Re: does anyone have OI and RC radio issues
 

I talked to IFI yesterday (more importantly an IFI guy that I usually see at my local competition - a good friend) and we went over some "possiblities" such as whats on the robot as far as motors and everything. I explained to him that we were using all of the 2007 stuff on a 2003 robot and he said that I may be tripping some breakers and thats why the OI loses the RC - I told him I doubt it since the robot A) Has not been used / touched in 3 - 4 years B) There was nothing ever wrong with the way it was wired and worked perfectly with all the 2003 gear. We ruled out any kind of interference that may make the 2007 stuff stop talking for brief periods of time. So as it stands to him everything is working fine and the OI - RC radio problem lies inside the robot and whatever modules that are in there to make it move.

He says that if all the Lights on the OI & RC are green at the time of Signal Loss that it is not actually the OI & RC that is losing the signal but a wiring problem that is making it lose the signal possibly all the breakers tripping at once. When I asked about me d/l the beta version aster code 14 he says that it won't solve my problem that its not software related.

I will probably try again with the 2007 stuff on another robot - maybe the 2001 robot since I know for a fact that one has not been touched at all and see if I'm getting the same problems. The 2007 stuff works great on tether just not on the radio. I will also try the 2006 radios if my old coaches let me and see what transpires from that. After I'm done doing that and see what happens I will call IFI again and hopefully someone else will answer and give me a different opinion. BTW the reason I'm not testing on the 2007 robot is b/c it's still getting the finishing touches and is not ready for the control system. Should I wait for the '07 robot to be finished or keep trying it on older robots that I know are Electrically & Pneumatically Sound?

Re: does anyone have OI and RC radio issues
 

From the IFI FAQ be careful when using this year's radios with older robots. Since they just released v14 of the master code with the most recent FIRST bulletin, you may want to use that for any older robot controller tests. It's not clear they've tested v14 with any older RC's, so if there's any trouble try using v13 instead.

Which IFI guy did you talk to?

I wouldn't assume the radios have an issue until you've used this year's controller with them, and the v14 update. IFI is turning our radios around in 1 day, so you've still got time to get them repaired if necessary. Using last year's radios with this year's controller also works perfectly fine.

Re: does anyone have OI and RC radio issues
 

Hrm let me be a little more thorough I used everything in '07 Kit - '07 Radios with the '07 controllers. Nothing was mixed matched unless you meant not to use the '07 Radios and '07 Controllers on a previous year robot.

Re: does anyone have OI and RC radio issues
 

Based on what I've seen, I think that it is undoubtedly a hardware problem within the RC or the RC Radio itself (most likely the radio), for two reasons. First, I think we need to assume that the LEDs on the RC are working correctly, because if they're not then there's a hardware problem right there, in the RC. Second, if we assume that what the LEDs tell us is correct, then we know it's a hardware problem somewhere between the RC and the RC Radio, because when the signal loss occurs, the only LED that changes is the Radio State, which becomes red, indicating that there is no radio connected at all. From there, once you make sure that the cable connecting the two is in working condition its easy to understand how the problem has to be within the RC or the Radio Modem. And when you try using older modems and have no problems, you can eliminate the RC.

Anyway, to me the only logical conclusion is that the problem is within the radio itself, especially considering that the teams that have received new radios have had no problems at all.

And my last question was, do the teams who received new radios still notice that it takes several seconds for the radios to initially synchronize?

Re: does anyone have OI and RC radio issues
 

Our team started experiencing problems again. We changed the configuration, per the third post located at IFI's Forums.

We found that when you make both perpendicular to the floor and away from metal objects they work perfect. But you get a metal object near one of them, or in there line of site they have problems at times. After talking to IFI, they had told us two things to read that post and follow what it said there, and to keep it away form metal objects. Now this seems weird considering most of the field is metal, and the rack in the center is all metal, and other robots are made out of metal. My guess is this year we are going to have problems on the field.

Re: does anyone have OI and RC radio issues
 

If you've done everything IFI suggested, called them, discussed your symptoms, and your radios are still having problems, they will give you a RMA number to have them repaired.

If you haven't tried their suggestions, or talked to them, and you're having problems...you should try their suggestions and/or talk to them. They're terribly helpful, and once it's clear there is no user error involved, will issue you the RMA.

Re: does anyone have OI and RC radio issues
 

Based on our tests, yes, but it doesn't really matter since its not really THAT long. Once they connect, they are good to go!

Re: does anyone have OI and RC radio issues
 

Obviously you wouldn't want to put your RC radio in the bottom of the robot next to the motors, and you could have some problems, BUT with good visible mounting away electronics and metal, and they still don’t work right, it is a serious problem. This is FIRST and there will be a myriad of metalic objects moving on the field at a time, so chances are, "no metal objects" in its line of sight is obviously not a viable possibility. I have Faith that IFI will have this solved in a week. Go FIRST

Re: does anyone have OI and RC radio issues
 

We got our radios kind of working by getting them at least 8" away from any metal objects. I did tests by blocking the OI radio with an aluminum plate and also positioning the RC radio around in the chassis (w/ and without metal nearby). It looks like if these radios are within 6-8" of aluminum they lose comm (orientation didn't seem to matter). Thats a big problem... We're looking at making a special plastic mount to get this thing up and away from everything else just to ensure a constant signal. The old radios work great no matter where you place them. However they have plastic antennas and these new ones have metal antennas. I wonder if that has anything to do with it. I think FIRST needs to let us use the previous years radios. Theres no way 2000 teams are going to be able to keep their radios in comm and away from aluminum obstructions.

ETA from the IFI Forum (and this IS the fix):
"Poor reception can also be caused from incorrect mounting and wiring. For best radio reception, follows the guidelines: 1) the RC and OI Radio Modems should be mounted high and perpendicular to the playing field. 2) Both the Radio Modem Case and the moveable Antenna should be perpendicular to the playing field. 3) The Radio Modems and DB9 Radio Modem Cables should be kept as far as possible from any High Current Wiring, Motors, and Victors ….etc. 4) The Radio Antennas should not be touching any other surface. 5) The Radio Modem Case and Antennas should not be shielded by any metal structure. 6) There should be a “Clear Line-of Sight” between the RC and OI Radio Modems case and Antenna. 7) Interference from another radio source can be solved by changing to a different practice channel."

But these requirements can be a real pain in the neck depending on your design...

Re: does anyone have OI and RC radio issues
 

This brings up some interesting issues with the radios this year. So that everyone knows, the FCC site has internal photos of the radios. These photos show a second antenna withing the black enclosure. It is positioned on the side oppositie the metal antenna. I expect that teams will find more stable communications if this side of the enclosure is positioned away from metal support structure. Only time will tell.

Re: does anyone have OI and RC radio issues
 

It attacked me too eric =(

Re: does anyone have OI and RC radio issues
 

While this helps, this in no way solves the problem :( Now it only cuts out every 10 seconds instead of every 5. 2006 Radios ftw

Re: does anyone have OI and RC radio issues
 

Call IFI, get an RMA, get them fixed, get them back. This is your last week to do it, and shipping only gets more expensive the longer you wait. They've only had 10 radios to date returned to them, so as it stands right now there is no mass reason not to use the 2007 radios.

Still, I wouldn't want to be at the first regional this year when there are 30 or 40 of these things on at once.

Our team will be getting our radios back from IFI bright and early tomorrow morning, and I'll report whether or not ours work like waialua's do now.

Re: does anyone have OI and RC radio issues
 

They will have 11 when my teams' get there I just sent in my teams yesterday they should be getting them monday! IFI told me to move the modem away from any motors or anything metallic so this is what I did I used a brand new DB9 Cord and put the radio next to the OIs Radio, Put the robot up on wooden chocks and guess what I still had problems and this time the robot wasn't even moving it the signal would just come and go randomly and I said before in prior posts I had this robot in a room where no interference can exsist. It seems like theres more to this story then they care to admit. When you have both the OI & the RC Radios within a foot of one another and neither one of them is near the robot and you still have issues I'd say that thats a defect right there. The 2007 setup worked flawlessly when I had the 2006 Radios hooked up

Re: does anyone have OI and RC radio issues
 

Is this a problem that exists with all Radios, or just some? We drove our robot yesterday for about 4 hours straight with no problems with losing communication.

Re: does anyone have OI and RC radio issues
 

Mike,
Putting radios close together can be just as much a problem as mounting next to metal or being far away. The high RF levels may just overload the receivers at that close a distance causing distortion in the receiver front end (preamp).

Re: does anyone have OI and RC radio issues
 

We are having drop out problems with our radio communications too and I thought we had these solved but they came back again....

When we initially had problems with this, our antenna on the robot was within 1 foot away from the drive motors. I then moved it and mounted it on a metal mast which is part of our arm lift mechanism and it was working just fine but now it sems to drop out every 15 seconds or so while driving the robot.

We notice the OI PWM red lights (for the drive motors) are on constant when this happens and sometimes the red No Data/Radio or the No Data lights on the OI light up and stay on for 20 seconds or more while the robot is dead in its tracks. I notice dthat reset clears this and will re-enable the robot.

The green lights on the robot antenna are usually blinking on an off and I have noticed that they do not blink as fast when this condition occurs.

Is this a problem with the RC, the OI, or the antennas?

I am beginning to wonder if this is a susceptibility problem with the antenna unit where we are picking up interference from something else... The location where we are testing the robot has a wireless network, could this be causing some of the problems?

We are also having run-on problems and will load the v14 bin file later today but from what I have read this will probably not fix the drop out problem.

We just wasted a day finding a bind up problem on one of the cim motors and now this is keeping us from the precious time we need...

Any suggestion of how we can over come this problem are greatly appreciated.

Thank you in advance for your advice on the drop out problem.

Re: does anyone have OI and RC radio issues
 

hmm no no problems but our antenna did break off...

Re: does anyone have OI and RC radio issues
 

1625 is having radio issues as well. In competition mode, the problem gets even worse. :ahh:

Re: does anyone have OI and RC radio issues
 

I am very concerned that as it gets close to the end of build season, many teams will be faced with this problem and the ramifications may be enormous such as not being able to test, waiting for new radios, etc.

Re: does anyone have OI and RC radio issues
 

yea i don't think we have any problems yet >.<

looking forward to your open house on thursday? ^^

Re: does anyone have OI and RC radio issues
 

Well as far as not being able to test & waiting for new radios the teams that know this problem already and who have / haven't decided to seek the IFI gods there is still hope for them. One of which is kinda lengthy - Tether the robot (and too be on the careful side if you choose to tether you robot make sure that you do not secure the tether cable competely If the robot should suddenly lose control make sure the tether cable is unscrewed from the OI or the RC side so that the plug comes out w/o destroying the tether port on either unit. Unless of course you put chocks under it then it isn't as lengthy & you can secure the tether cable if you wish.) The other is to use the 2006 Radios which work perfectly with this years OI & RC. Of course these are temporary solutions and will probably need to resolve whatever issues with their radios while the robot has been shipped and hopefully have the newer / re-built radios in time for their 1st. regional.

Like many have said and I will repeat - IF YOU HAVE PROBLEMS WITH YOUR RADIOS TRY PLACING IT AWAY FROM THE METAL CHASSIS & ANY MOTORS, TETHER YOUR ROBOT TO MAKE SURE THAT IT'S ONLY A PROBLEM WITH THE RX/TX ON WIRELESS AND NOT ON A DIRECT CONNECT LEVEL, IF IT'S A PROBLEM WITH THE ROBOT BEING WIRELESS THEN USE THE 2006 RADIO MODEMS, IF PROBLEM IMPROVES WITH THE 2006 RADIO MODEMS THEN CONTACT IFI AND GET A RMA AND SHIP THE 2007 RADIO MODEMS BACK SO THEY CAN REPAIR / REPLACE THEM AS NECESSARY (MAKE SURE YOU ARE VERY THOROUGH WHEN REPORTING THE PROBLEM OTHER WISE THEY WILL FLOW CHART YOU TO DEATH. THE MORE THOROUGH YOU ARE THE LESS QUESTIONS YOU WILL NEED TO ANSWER THE QUICKER YOU CAN OBTAIN AN RMA#. AND AS AL S. HAS SAID MANY TIMES CHECK YOUR WIRING VERY CAREFULLY, WE'RE ALL HUMAN AND MAKE MISTAKES VERY EASILY ESPICIALLY UNDER PRESSURE.

Re: does anyone have OI and RC radio issues
 

WE were successful at correcting the problem that we were having last night..

Here is what we did:

1). We moved the antenna on the robot so that it is now as high as we could get it and made sure the antenna itself was totally vertical (perpendicular to the track).

2). The antenna unit was mounted to a metal vertical mast on our robot so we attached an "L" bracket to this metal mast and a piece of 1/2" plywood and attached the antenna to the plywood. The antenna is also cable tied to the plywood with a small piece of foam to cushion it and to keep it from touching metal.

3). We re-routed the data cable from the RC unit on the robot to the antenna unit so that is was not near any motors, victors or spikes.

With these three things we did not have one drop out condition all night long...

What a relief it is to clear that problem up... only a few more other problems to figure out.

Re: does anyone have OI and RC radio issues
 

You know what burns me more then anything is that IFI is 1) very doubtful of our problem and that we the programmers and team members are imagining things when the RC system fails for whatever reason, 2) forcing us to build around a problem in which they caused.

Basically this is what they are doing: We IFI have chosen to upgrade the hardware on the Radio Modems to make it bigger and much more harder to mount. You have to mount our radios in such away that it is put in danger of breaking if you don't mount it to our guide lines you will suffer signal degradation. What ever problems you come across are through your own fault and not of ours even though we've tested unsuccessfully the new radios at an offseason event. We will however allow you to send your radios to us for repair / adjustment or replacement if you can correctly identify the problems you are having.

It's bad enough we have to design a robot within 6 weeks to FIRST specs. Now we have to do it to IFI specs to. I don't like this one bit but hey if anyone thinks otherwise then please share your opinion.

BTW got my teams radios back but don't have any time to test them. Much to Much work left to get done. I guess we'll find out come the first regional. :ahh:

Re: does anyone have OI and RC radio issues
 

Just an update from us. We've mounted this thing in the best possible way you could imagine. It's high, its amost 1' away from any metal ( mounted to a plastic panel up in the air. It's vertical and the wires route clearly away from everything that could cause interference. AND WE STILL HAVE DROPOUTS. Not as many but they happen every minute or so, for a second or 2. I'm convinced there's nothing you can do to make these things work properly. They are definitely defective and poorly designed. When I get to our regional the first thing I will do is ask if we can use the 06 radios.

Re: does anyone have OI and RC radio issues
 

Dan,

First of all, let me say that I respect your opinion and your posts have always had merit. I am going to vent a bit and I apologize for using you as a target but feel it better you than using a student or someone less experienced.

Now to the meat of it:

If you follow that path, you will certainly fail.

Let's assume that the 06 radios work better and that the 07 radios have a systemic problem. If you were running the competition and a number of teams brought the 06 radios and petitioned to have them allowed, would you allow it? Would it be fair to the teams who did not bring 06's? How about the rookies who can not get 06's?

Answer: You could not allow the 06 radios to be used because everyone waited too long to complain!

I looked on the IFI forum today and found only 3 posts about radios not working since the kickoff. Let's assume another 10 teams called on the phone. This is only 13 teams out of 1307 having a problem as far as they know. There are a lot of companies out there which would love a 0.1% return rate.

Your team (and everyone else who is having problems), MUST make this issue clear to both FIRST and to IFI.

$@#$@#$@#$@#$@#ing and moaning on CD will not resolve the problem.

OK. I'm done now and, once again, I'd like to apologize for singling you out. Please forgive me...

Mike

Re: does anyone have OI and RC radio issues
 

Our team was one of the first to report problems to IFI, reportedly the 5th to contact IFI and the 3rd to return radios for evaluation. IFI gave them a once over, but didn't really find anything wrong.

Testing since their return 2-3 weeks ago, shows an improvment, but not resolution, and I have continued to communicate that message to IFI with hopes that they would be able to provide a solution.

In all other areas, my contact with IFI has been a positive one, and I think that they've responded to my requests in a very reasonable and timely manner, so when it comes to the problem with the radios, I've given them the benefit of the doubt, and for the most part I still do.

Recognizing that we are down to the wire here, and still don't have a viable solution in hand, on Thursday I once again put the question to IFI if they wanted to RMA our existing radios again, or if they wanted to swap them out with others, and also indicated that I felt it was time to elevate this issue to FIRST's attention, and the response was that they'd pass the request up the food chain.

On Thursday afternoon, I sent an e-mail to FIRST's team contact e-mail found here and outlined our ongoing problems with the radios and that we were not receiving a solution to this problem from IFI. I ended by suggesting that the regional events make use of 2006 and prior year's radios, and that all non-rookie teams bring old/spare radios to provide to the 2007 rookies.

I have also communicated this same information and request to the regional FIRST contact's to pass along to FIRST as well.

So clearly I concur with the thurst of Mike's input here in that any team that is continuing to experience a radio communication problem, that has already worked with IFI and not yet obtained a satisfactory solution, that it is probably time to make certain that FIRST hears your concerns. Ultimately it is their call as to how to fairly address the problem.

There seem to be many teams reporting success with their radios, so clearly they will have an additional advantage over teams such as ours.

Use the FIRST e-mail address in the link I posted above to make your concerns known. You can also find FIRST regional contact information on this webpage.

Please keep your comments and concerns constructive an professional, and please refrain from bashing IFI. The reason for the change in the radios was outside of their control, and while I don't factually know the timetable they had to work with, I suspect it was quite short.

Re: does anyone have OI and RC radio issues
 

1902 is having these problems. It wasn't seen until we placed the radios in a real robot, before we tested in a VEX like setup.

We will send an email to IFI also.

Re: does anyone have OI and RC radio issues
 

We DID contact IFI, they kindly directed us to the forum and said that should fix it, have a nice day. In other words we got that same sentiment I'm seeing other people recieved, its not our equipment its how your using it. And that was about 2 weeks ago.

Re: does anyone have OI and RC radio issues
 

We didn't see the problem until we tested heavily this week. I think a lot of teams are having the problem but just don't see it yet.

Kind of scary thinking your bot can stop at anytime.

Re: does anyone have OI and RC radio issues
 

(I haven't gone through most of this thread.)

We can confirm that our cellular phones are interfering the radio communication between our OI and RC. It seems to reset or otherwise turn off the OI completely -- our robot stops responding to commands, the LEDs on our OI turn off and things are otherwise completely useless.

Is this a problem with our radios or is this a generic defect with the new IFI radios?

Thanks. :)

Re: does anyone have OI and RC radio issues
 

While the radio issues are frustrating, please understand one thing. IFI didn't "choose" to upgrade anything. The guts of the old radios are obsolete. In fact, so obsolete that the only thing to do was redesign. It just wasn't possible to create another 1300 sets of the old ones. Why are they so big? That's what it took to try and make the right thing happen. IFI had a significant challenge in making the new radios work. They were testing prototypes as early as July 2006 in competition conditions and were still testing during offseason competition in November 2006.

This is not a situation IFI created, but rather a huge challenge they they have been working like crazy to overcome. The solutions they are providing are the best that currently exist.

Re: does anyone have OI and RC radio issues
 

Lets all remember that every team is under different circumstances. Some teams havent reported issues because they didnt have a robot until maybe very recently, enough for them to test.
We were fortunate to have finished a little earlier, thus being the 1st ones to start this thread and report it. Im sure teams are more worried about other bigger things such as building a robot.
For example, we just finally put the diagnostic light on and the solid state relay doesnt work. Then we find out that some teams got the wrong one, which is the case for our team. In addition, we find more info on other threads.
People wont search some threads if there is no problem/challenges to search questions for.:D

By the way, will the competition have spares? We participate the 1st weekend of competitions already!

Re: does anyone have OI and RC radio issues
 

I think we have found a correlation between this and the use of cell phones, especially if you are getting a call or on the phone. Today I got several phone calls while right near the robot as which point RC and OI lost communication. coincidence? I don't think so though, I am not 100%. I'm no engineer or RF expert but thats what I have been able to observe.

Re: does anyone have OI and RC radio issues
 

We had an open house today. Students have reported occasional communication glitches over the past few weeks, but when there were a couple dozen spectators gathered around the field, things got very squirrely. After the guests moved away, all was well again. My guess at the time was that it was all the cell phones in people's pockets causing interference.

Re: does anyone have OI and RC radio issues
 

so whatever the technical jargon is, these new radios are not as efficiently "strong" as the old ones when other potential interferences occur.

That's so strange. I dont know what it is about our new radios, but we didnt follow anyones advise about where to place them (away from motors, etc.). Our objective was to put it somewhere convenient first. In fact, our's is laying down with the antenna sideways to fit under our ramp platform. We also have a lot of "cell-phones" around including our open house.
Conclusion: NO problems with our new radios.
Must be some non-uniform device inside our radios that vary between teams.

Re: does anyone have OI and RC radio issues
 

Mike:

I did the same thing as Dan and got the same response from IFI - read the forum and try all the fixes and have a nice day. I even told them that our radios were cutting out in a small closed room sitting on a table a few feet from each other, while we were bench checking the electrical system. No cell phones around, no metal from the robot, direct path between antennas. Never an indication from them that there is a systemic problem. The only reason I called them at all was I saw the hundreds of posts on CD from teams who were having problems, and the advice from one person who had received an RMA number. I did not post my problem here - it looked like it was pretty well covered. I believe your estimate of 10 calls is grossly low.

Re: does anyone have OI and RC radio issues
 

We just had our "pre-ship mini-meet" here in Central Texas, and we had a number of issues that were very, very strange - I would say they all could be related to the radio modems. It seemed as if when our robot got near our team coach, the robot would be very unreliable. In one event the drivers were pushing the joysticks to make the robot turn, but the robot suddenly became completely nonresponsive, though there was no indication on the LEDs that the radio was out.

Our shop just isn't large enough to do any kind of really decent radio modem tests, though we never had any problems in our shop with the OI and RC between 5 and 10 feet from each other or near our team coach or other sources of interference. This is making us very concerned, we've followed all the regular best practices specified by IFI but there were too many instances of radio unreliability this weekend.

-Danny

Re: does anyone have OI and RC radio issues
 

I'm so pro-First and pro-IFI its crazy. But, I don't like the fact that IFI is taking the defense that it is our problems, mounting etc. It is obviously a FIRST-wide problem, and a radio design problem. Ignoring the fact that it is a faulty design won't make this go away. Some teams say their new RMA'ed radios have worked better than their first ones.

Our radios lose packets at 3 feet away sitting on top of a wooden table. This year we have a new communications engineer mentor who basicly said, if the connections are tight, and it is still losing sync at that distance, nothing is gonna fix these radios.

As I stated a week ago: IFI will solve these problems, Go First.

Re: does anyone have OI and RC radio issues
 

Letting veteran teams use old radios should be allowed in this situation. FIRST is all about sharing and caring. I am sure it wouldnt be unfair for teams that dont have access to them because others would share during the matches.
No one would blatently let a team suffer because of malfunctioning radios.
This would actually help IFI with the demands to fix the new radios.
Even though ours works now, I am still advocating for others.
:]

Re: does anyone have OI and RC radio issues
 

At our scrimmage in AZ yesterday, there were several incidents of odd radio modem communications loss. Not sure why. It could be because of the radios but then again it can be battery problems, lose wiring, etc.

I think the real problem, for us anyway, is we don't trust the new radios because of all the bad reports. We kind of expect to see radio problems.

I would feel more confident if we were using the older radios. The problem with that, of course, is rookie teams do not have older radios, but veteran teams, who have been issued a radio set every year, have multiple sets and there should be plenty in the FIRST pool to provide everyone at competitions with a pre-2007 radio modem.

Actually, at competitions we only need 6 older radio sets, one for each robot competing. Another dozen or two for the teams in the queue and it seems the radio problem would be solved for this year.

Re: does anyone have OI and RC radio issues
 

We had our practice match yesterday, only about 4-5 robots really moving.

There was at least two of us having the radio problems. It goes like this:

1. Radio modem lights flash rapidly back and forth (Standby and Receive)
2. RC lights flashing wierdly.
3. OI lights flashing wierdly.
4. Lasts about 5-15 seconds not enough time to capture what exactly is happening.
5. It seems what ever the robot controller mode it was in stays in. Yesterday it was in fast forward and went into that radio drop out mode and it stayed fast forward and bot climbed the rack to a 45 degree angle. Didn't know it could do that. VERY DANGEROUS, YOU CAN NOT STOP OR CONTROL ROBOT WHEN IT DOES IT.

Does do it more when cell phones are around.

Needs to be fixed or we will have dangerous situations with robots out of control.

Re: does anyone have OI and RC radio issues
 

Alot of people are commenting on Cell Phones causing problems with the radios.

I really don't know what they think is gonna happen when they throw 6 robots on the field on flaky wireless connections in a hockey arena full of people with cell phones. Seems like asking for trouble. Our 07 radios seemed to work sort of, but the latency is even an issue. The pre-07 radios were awesome, and I still want to know why we changed. You say they couldn't build another 1300 of them... why not? These are far less reliable, MORE difficult to mount (what was that about equivalent technologies getting SMALLER as time goes on?). I think that the problem is very few teams actually assemble and test their controls in an environment similar to competition, BEFORE the week before ship. THIS is the problem. If this had been construed to IFI they might have been able to fix the situation, or tell FIRST to allow pre-07 radios. I know 1075 has 3 different sets of pre07 radios, and they're all infinitely better than these. We've been testing with 06 radios... supposed to put 07 ones back on it today. Mounting them as good as is possible may still not be enough... there's no way we can mount them 6-8" from any metal.

Re: does anyone have OI and RC radio issues
 

We followed the "best practices" from IFI forum for mounting and have the correct version of code, and it still drops occasionally. We'll contact IFI today and make them aware of our difficulties, too. The old radios - which we have 6 pair, work fine!

Re: does anyone have OI and RC radio issues
 

From what I understand, some of the parts in the old radios were from older cellphones and were obsolete. They had to redesign because they couldn't get a hold of the older parts any longer.


We have Radios from 9 years of competition at our shop... and we would be more than glad to bring them to a competition to lend out to people. I wish FIRST would allow this, because if things continue on as they are with the newer radios... People can expect to be in control of their robot less than half the time during competitions.

Re: does anyone have OI and RC radio issues
 

We had our pre-ship scrimmage yesterday and experienced the same issues. I had taken the precaution to download the U14 beta mastercode but it did not seem to solve the problem. We didn't have any issues with run-away robots but we did experience the dropouts and glitchy operation. All of the teams running saw the same issue.

Steve Stark

Re: does anyone have OI and RC radio issues
 

Nice to see everyone having this problem, I was worried it was our electronics. Being a rookie team, when the robot cuts motion for not reason, it freaks us out. We had no idea what was wrong.

Re: does anyone have OI and RC radio issues
 

We are finally system testing (driving + arm + everything else), and we are having the same or similar issues - robot stops moving for about 1/2sec, OI light "No data/radio" flashes, and then everything goes back to normal. Seems to happen with increasing frequency as we slowly add in more and more of our software (presumably putting a higher load on the PIC), which is bizarre because the radio is handled by the master processor, which has nothing to do with us.

Re: does anyone have OI and RC radio issues
 

I was at the Sussex, WI mini-regional today, and everyone there had radio issues.

Re: does anyone have OI and RC radio issues
 

We did cell phone tests tonight. BINGO! Make or recieve a call within 30 feet of the bot and it starts glitching bad (this distance may be greater but I was on the phone and walked away from it and it seemed to get better after I was in the next room). Then also just hold it near the bot (while not in use) and every 15 seconds or so it starts fluttering.
So whats the answer, ban cell phones from the competitions? Can someone get IFI to read this thread? Someone said if it is a cell phone issue, you can't fix it. Which I gather those frequencies can't be altered out of that range? I contacted the FIRST Florida rep (Charles Kennedy), and he's waiting to hear back from FIRST. The way I see it, this is a bigger issue than the banebot problem because we all need to use these radios.

Re: does anyone have OI and RC radio issues
 

I bet an update will come out soon saying that old radios will be allowed.:D

Re: does anyone have OI and RC radio issues
 

We were doing some testing tonight (finally!) and during the first 5 minutes our driver was driving backward, the bot kicked into high gear and started flying backward. the driver let go of the controls and the bot kept moving. Luckly, we were using a dead man's switch to cut the power and we were able to stop the bot and nobody got hurt (the bot survived as well). the RC antenna was not surrounded by any metal, there was a direct line of sight between the antennas and the distance was about 10' or so. We switched to last years antenna, and everything seems to be ok.

Re: does anyone have OI and RC radio issues
 

The RF decks in the eWave designed radios were made by Uniden, and those were no longer available. It is reasonable to conclude that the modules were made for consumer cordless phones, and products of that type. These are channelized, narrow bandwidth, analog FM full duplex transceivers operating as unlicensed devices in the 902-928MHz ISM band.

Re: does anyone have OI and RC radio issues
 

Dan, We did the same thing as well today. Everyone in the room 1 by 1 would call their voicemail with their cell phones. We noticed an interesting pattern, while my service ( Sprint ) never seemed to cause the robot to lose radio contact, EVERY SINGLE TIME a cingular or AT&T serviced cell phone was used the robot would immediately lose radio signal. We also found that each time the phone would reconnect with the towers to re-establish signal the robot would break the frequency.

My service is Sprint, and the other sprint phones also never-( or atleast noticeably ever ) tripped the radio. Now the way I understand it Sprint uses a different cellphone technology than both Cingular and At&T. Its this technology that we believe is tripping the radios. We know for a fact that the cell phones would trip the radio, because we tested repeadtly for about 15-25 minutes, turning them off walking away hiding them then calling them or making calls with them.

I don't claim to have any clue whats going on, this is probably apparent due to the vagueness of my post however I do realise there is a problem. During our skrimmage yesterday, there were many times where people came very close to being hurt because of the radio frequency loss, then the robot suddenly coming to life near the sides of the fields. You don't have to be an electrical engineer to realise this is a problem. This type of problem not only can greatly corrupt the competition, it could also cause some significant safety issues, or even potential damage to our robots, I'd hate to see a robot lose radio contact as its driving up a ramp and flip over causings thousands of dollars in damage.

I really hope that IFI will do something soon. I completely agree with you Dan this is a HUGE issue. In the case of the bane bots, if problems occured, at the very worst we could always change companies, or come up with custom solutions. With IFI there is no other option. I know they realise this, and trust they will come up with a solution as they always do. Lets hope it comes before regionals, otherwise get ready to see some of the most interesting/unsightly regionals in years.

Re: does anyone have OI and RC radio issues
 

Sprint and Verizon actually use the same technology (CDMA). The more important difference is that Sprint's network is entirely in the 1900MHz band, while Verizon primarily uses 800MHz. So, your findings are not surprising. Verizon's phones are using frequencies very close to those used by the radio modems (902-928MHz).

Re: does anyone have OI and RC radio issues
 

To a certain extent, IFI's hands are tied in terms of being able to solve this problem. If they were to modify the design, it would most likely require recertification for the FCC equipment authorization.

I'll again echo my previous statements that in all other respects, my experience with IFI has been timely, professional and reasonable. While I'm sure they can solve the problem, the bigger question is whether they'll be able to do it in both a timely and legal manner.

Based upon what I saw today at the local regional in Sussex, WI, many teams operated successfully, and there appeared to be some interference issues with teams operating on the same channel, however even when the event organizers dutifully checked to make certain everyone was on the correct channel, there were still some teams experiencing problems to the extent that it affected the outcome of the match.

In a couple of instances, I was able to see the lights on the robot's radio showing the radio going into standby and then attempting to find its operator interface again... and this is with less than 10 feet between the OI and the robot.

Instances where more than one radio pair attempted operation on the same channel is quite easy to spot as the Tx/Rx LED's on the radios will be almost constantly illuminated as opposed to the normal alternate flickering. So once you know what to look for, it is pretty easy to see the difference between interference and a radio that has just lost communications with its partner.

One of the teams at todays event simply chose to use the older radios.

While its good to hear that many, and perhaps most, teams are not experiencing an obvious problem, unfortunately our team is not one of those.

Teams experiencing problems, should make all attempts to make your FIRST contacts aware of your individual situations.

At this point, the reasonable and conservative answer would seem to be the use of the old radio's. I'm sure most of us have 18 other design implimentation issues that our time would be better spent on.

Re: does anyone have OI and RC radio issues
 

A quick correction to Dan's post: it was the Cingular and AT&T phones causing the repeatable interruption.

My Verizon and and others' Sprint phones caused no interruption as far as we could tell.

Re: does anyone have OI and RC radio issues
 

Yes I'm sorry my bad, it was late when I made that post. It was Cingular and AT&T, Verizon and Sprint were seemingly safe.

Re: does anyone have OI and RC radio issues
 

For those interested in some additional background...

Both the old (eWave) and new (IFI) radios use unlicensed (Part 15) frequencies in the 902-928MHz band. Both radio designs use relatively narrow channels, as opposed to a spread spectrum design. Both designs operate full duplex, with the OI and RC radios transmitting near either end of the spectrum.

"Cellular" carriers use spectrum allocations in the 824-849MHz and 869-894MHz, with the subscriber units transmitting in the lower channel block.

"PCS" carriers use spectrum allocations in the 1.8-2GHz range.

Cingular/AT&T uses GSM (Groupe Special Mobile) as the air access standard for their subscribers. GSM is a TDMA (Time Division Multiple Access) standard which assigns each subscriber a fairly precise time slot in which your device transmits a burst of data, representing compressed voice and control information. The packet frames are sent at a relatively low repitition rate of 217Hz or one of its submultiples.

That 217Hz packet rate results in a rapid on/off keying of the transmitter in the phone. The resulting modulation is AM (amplitude modulation) which can be problematic for many devices, whether they are radios or not. The succeptability some devices have is that components like diodes and transistors make good receivers because they will rectify the incoming signal, and by extension components like operational amplifiers (op-amps) that have transistor inputs are among the most succeptible for near field signals.

CDMA (Code division multiple access) is a spread spectrum technology that assigns each subscriber a PN (Pseudorandom Number) sequence with which to scramble their transmissions. The transmitter technically remains on the air while the frequency that it operates on is rapidly changed in a psueudorandmon manner. Phones that use this technology will typically not impact succeptible devices as much as a device using a TDMA/GSM type of modulation scheme.

Cingular and AT&T Wireless, pre-merger, both held "Cellular" and "PCS" licenses across the country, the local use of which was determined by how they came to own the licenses in a given market. Both companies heritage, in some markets, trace back to the wireline LEC (local exchange carrier) license grants in the early 80's where the LEC was given one 'cellular' channel block, and a wireless carrier was given the other 'celluarl' channel block.

Starting in the 90's, the newer 'PCS' spectrum was auctioned to new carriers, and companies such as Sprint got into the cell phone market, and established cellular carriers also bought spectrum in other markets.

Sprint uses PCS channels for their national system, and is CDMA.

Verizon Wireless came out of the merger's of Bell Atlantic Mobile Services (BAMS), GTE and Vodaphone, and the combined holdings and subequent acquistions and expansions have all utilized CDMA technology as their digital air access standard. In markets where Verizon's heritage is traceable back to the origional LEC, largely in the east, they primarily operate on celluar channels, though many areas both celluar and PCS are used for capacity. Local to me, Verizon uses PCS channels obtained through their acquistion of PrimeCo wireless which had constructed systems in the midwest, and if I remember correctly also had a prescense in Florida.


If celluar phones utilizing GSM/TDMA technology are found to drive the IFI radios nuts, then I suspect that Nextel subscriber units would also have the same potential for problems.

Nextel is neither a cellular nor PCS carrier, they are a SMR (Specialized Mobile Radio) licensee that has a patchwork of 800MHz spectrum holdings in which they have constructed a cellularized, full duplex, two-way radio network. Nextel uses a Motorola propriatary TDMA technology marketed as iDEN (integrated Digital Enhanced Network). iDEN's packet rate results in the subscriber devices transmitter typically being modulated at 22Hz.



In our teams situation, I've not attempted to torture the radio's with any cellphones, nor has anyone been on their phone's nor has any phone alerted (i.e. rang) during our tests. In many cases, I've been the only one present, and my phone is Verizon CDMA using PCS channels.

I'm not saying that there isn't a problem with susseptability from cellphones, just that in our case, I believe we are being affected by a different problem, as our packet loss events appear to always be tied to large demands on our electrical system.

Re: does anyone have OI and RC radio issues
 

This evening I implimented code to watch for packet loss, for more information see the details and example code in this thread.

With a packet loss counter displayed on the operator interface, I had a couple of Cingular (i.e. GSM) phone users setup calls within proximity to the 2007 radios, and boy did the packet loss counter take off. This was not a difficult problem to reproduce at all, nor did the phones appear to need to be particularly close to the radios. We didn't do range testing to see how far away they would still cause problems.

With eWave radios, the problem could still be produced, but the phones had to be within about 12-18" before some minor packet loss was noted.


My CDMA phone affected neither.


I also tested with a /\/\otorola 450MHz 5W handheld and found that it was fairly difficult to disturb the 2007 radios, but when I did, they took quite a while to recover, and it seemed to be longer than it normally takes for the radios to sync in the first place.

When I tried the same test with the eWave radios, I found that they were actually more succeptable to interference from the commercial handheld radio than the 2007 radios were. However, the eWave radios never experienced anything more than a few packets being lost when the commercial radio was keyed, whereas the 2007 radios lost sync for up to 20 seconds as a result of a single transmission on the commercial handheld.


With regard to the V14a firmware, my test code seemed to indicate that the robot controller will disable the outputs when 8 consecutive packets are lost. My number could be off a bit, as I sometimes saw as many as 12 missing packets prior to the RC disabling the outputs, but its right in that area somewhere. In otherwords the outputs will be disabled 200-300ms after packet loss starts to occur.


With the packet loss counter displayed on the operator interface, over several minutes of operation, both the eWave and IFI radios showed occaional packet loss counts during the regular course of operation, however the packet loss rate was higher for the IFI radio than the eWave radio. I won't quote specific numbers nor quantify that statement as I wasn't making a specific expermient to instrument packet loss.

The environment that I was testing had no other 900MHz signals present, as verified with a spectrum analyzer.

Overall, the IFI radio design appears to be quite a bit more succeptable to cellular phone interference than the eWave design, however the eWave design was more succeptible to 450MHz two-way transmission.




From a design curiosity standpoint...

Additional testing shows that the IFI designed radios are FSK radios using channels spaced 150kHz apart. The RC radio channel 1 starts at 902.100MHz and works up from there. The OI radio channel assignments are less obvious, and not sequential, operating in the 922-928MHz portion of the band.

The eWave designs operate on 50kHz channels with the RC side transmitting on the lower frequency channels, just like the IFI design, and appear to be AFSK. Presumably the AFSK approach avoids needing to design the transmitter/receiver to be able to essentially pass/recover data down to DC. The latter results in a slightly more complicated synthesizer design because the PLL reference needs to be modulated in addition to modulating the VCO.

The IFI FSK signal appears to contain a ~3ms pre-amble prior to the data, which I presume is to center the recievers data-slicer, then sends the data, and then sends what appears to be a post-amble. Given that the data is true FSK, its not clear why a post-able burst could be helpful.

I also noted that the signals didn't appear to be properly pre-emphasised, so the higher frequency content of the signal didn't deviate as widely as the lower frequency data, nor was the signal necessarily well balanced. Depending upon the data-slicer design, this could certainly result in a reduction of performance.

While a bit hard to tell, the signal encoding didn't appear to particullarly try and place a limit on long strings of 1's or 0's as long periods of mark and space were evident, which again can make the design of the data slicer a bit more challenging.

Again, this last bit is offered just as insight into the radio's design. I have no reason to believe that the modulation methodology plays into the performance problems that I've noted, and believe are tied to power supply issues, nor should they play a great part in the receivers succeptablility to GSM/TDMA type transmissions... that is unless the succeptability problems are related to RF getting into post receiver circuitry.

Re: does anyone have OI and RC radio issues
 

Makes you want to think that the AGC delay release is set a little too long doesn't it.

Re: does anyone have OI and RC radio issues
 

So is playing with broken radios this year a part of the game challenge?
..

Re: does anyone have OI and RC radio issues
 

They should tell everyone with Sprint & AT&T service to shut off their cell phones :D

Re: does anyone have OI and RC radio issues
 

Ben,

People don't turn off their phones in restaurants, movies theaters, meetings or Broadway shows. They text message while driving down the interstate. They even ignore FAA regs and jeopardize their very lives by using phones while taking off on commercial jets.

What chance do you think you have in getting people to turn off their phones at a robot competition?

JMHO.

Mike

Re: does anyone have OI and RC radio issues
 

our radio channels are different RC is 32 and OI is 40 anyway to fix and i'll try it at regionals

Re: does anyone have OI and RC radio issues
 

I would certainly hope not...

Re: does anyone have OI and RC radio issues
 

I wonder if first will let you use last years oi and rc if yours does not work????

Re: does anyone have OI and RC radio issues
 

It doesn't work the way you are describing it.

The radio 'channel' involves a pair of channels between the OI and RC.

The channel pair is determined from the OI side via the dip switches OR via the competition connector. The OI radio begins transmitting on the selected channel, and the RC radio scans all available channels until it finds an active transmission that contains your team number.

The initial tethering process after setting your team number on the OI is how the RC comes to know which 'team' it is associated with.

Set your team number, tether the OI and RC, remove the tether and you should be good to go.

Re: does anyone have OI and RC radio issues
 

For what it's worth -- we just received an e-mail from the Pacific Northwest Regional Director asking that veteran teams bring along 2006 radio sets to act as backups, should they be needed.

Re: does anyone have OI and RC radio issues
 

The Regional Committee Chairman for the Los Angele Regional will be doing the same if she hasn't already. Team 330 alone has six working units of the old radios. If all of the veterans in our area bring their radios as well we should be well covered.

Just a reminder... bringing old radios is a cheap, low impact fall back solution. We will at least start with the new radios.

ChrisH

Re: does anyone have OI and RC radio issues
 

If there are too many problems, a decision will have to be made on whether FIRST should use the new radios or old radios for a particular regional. I say this because you cannot just keep switching radios on robots and player station randomly. It will create too much confusion and maybe unnecessary work. It will also waste a lot of time.

Luckily, we sent ours to IFI and they told us that there was a bad board in it. They also confirmed that it is now repaired and it will work flawlessly at the regional. I hope everyone else having problems connected with IFI(and something was done about it).

Re: does anyone have OI and RC radio issues
 

All teams should closely examine team update #15 for vital radio information:

http://www2.usfirst.org/2007comp/Upd...pdate%2015.pdf

Re: does anyone have OI and RC radio issues
 

No radio trouble for us at BAE Regional.
We had a ton of trouble with our radios at a pre-season mini-meet and during our own testing sessions. When Cingular cell phones rang within about 30' we lost communications. The radios also broke up at other times, not sure why.
** But with the v15 RC update, and the update done by IFI to our RC Radio [and everyone elses] at the event, we had absolutely no radio problems. I just wanted to say thanks to IFI for working the problem and getting it solved.

Re: does anyone have OI and RC radio issues
 

Ditto. Also, Cingular cell phones wiped all the room key cards at our hotel...

Jacob

Re: does anyone have OI and RC radio issues
 

The IFI guy at the NJ Regional (Rick) had each team informed to bring their radios to a secluded room at the arena and he would flash the RC Radios with new software. The process took all of about 5 minutes to complete. While the update made the radios work a bit more better, it also made the location of the radios in teams robots seem more of the problem and a few teams had to re-locate the radios so there were no more problems with data packet loss. All in all once all the RC Radios were upgraded and the RC's upgraded to v15 there were little to no problems with the robots working on the field. You still had interference while working off the tether and no interference on the tether but thats to be expected while working in a room down the hall, at a practice field or in the pits.

Re: does anyone have OI and RC radio issues
 

Actually, at competition it's expected that you never run the robot without the tether unless you're on the field. If you used your own OI radio, you were interference.

Re: does anyone have OI and RC radio issues
 

IFI did a great job coming up with the fix(es) for the radios. At NJ, I did not notice any radio problems - which is better than even previous years. Nice. I love it when there are less unnecessary problems to worry about.

Re: does anyone have OI and RC radio issues
 

Just so you all know, the IFI people use a monitor device that shows your team number and a variety of stats on your robot when you are using the radios, even in the pits. Use your tether at all times you are not on the field or you may invite a visit from a friendly inspector or IFI rep.

Re: does anyone have OI and RC radio issues
 

Dumb question from a Mechanical Engineer: by RC radio, do you mean the box with an antenna that is connected to the RC by a cable? Do they need the IO radio as well?

Re: does anyone have OI and RC radio issues
 

Yes, IFI is updating the "box with an antenna that is connected to the RC" on the robot, and No, IFI is not doing anything with the teams' OI radios that you would attach to your driver control panel (or wasn't in NJ, anyway).

Re: does anyone have OI and RC radio issues
 

Just the RC Radio needs to be bought to IFI. Teams will be notified when they get to pit admin. at their regional where to bring their radios so that IFI can do the upgrade. Your Radio should only be upgraded once by IFI so if it was done already you may not need to do it again unless it is your first regional.


I was using an example. I'm pretty sure teams know to run their robot on the tether cable when in the pits. But just in case their are a few rookies attending event I would throw that little tid-bit in.