does anyone have OI and RC radio issues
 

Hi all,
We hooked up our drivetrain with the OI and RC complete. As we were testdriving our robot so far, we noticed that the radio would go to "no communication" mode and the controllers were basically dead and not controlling the robot. It is intermittent.
anyone have issues or solutions with this problem?

Re: does anyone have OI and RC radio issues
 

When the radio doesn't work, the first response should be to tether up and see how things go. If that does not work then you can start to troubleshoot wiring errors, team number settings, dead batteries, etc.

Re: does anyone have OI and RC radio issues
 

It's not that the radio just loses connection but that the user loses control. Even the disable switch doesn't work. It's my understanding that if the robot loses contact with the OI it should disable itself. It doesn't. The user simply loses control for a short while.

Re: does anyone have OI and RC radio issues
 

We also experienced this. At the time, we were running the 2006 OI. Robot seems to be locked in the last data packet sent by the OI. Tonight we will continue testing with 2007 OI to replicate the problem. Because the robot thinks it has good data, disable switch does not work, leading to a very dangerous situation. It seems to happen for a matter of seconds, and return to normal operation. Because of the short duration, and random nature, haven't been able to read the diagnostic lights on the OI. It has not occured with the tether cable.

Maynard

Re: does anyone have OI and RC radio issues
 

I strongly suggest that you report this problem to IFI.

Re: does anyone have OI and RC radio issues
 

This sounds similar to last year's "8.2 volt" bug. It never bit us, so I didn't pay close attention to the prescribed fix. I think it involved modifying the linker script to make a bank of memory out of bounds. If nobody pipes up with a good pointer to the details, you can search the forums.

Re: does anyone have OI and RC radio issues
 

I believe it's a problem with the communications. With the 8.2 problem, I didn't see any reference to the disable switch failing. We were using the 2006 OI with the new radios, so it may be a change in the radio communications which causes a intermittent problem. I have notified IFI of the situation. We have the new libs, and linker file installed.

Maynard

Re: does anyone have OI and RC radio issues
 

Have you updated the Master Code on the 2006 RC?

I believe that the new V13 master code for 2007 has changes for the new radio.

Re: does anyone have OI and RC radio issues
 

Yes, that sounds very familiar! :ahh:

Also, for those who think the problem may be completely unrelated to the 8.2v bug, remember that when you corrupt a section of memory on a running computer program, the results are (almost) completely unpredictable. A section of memory that is receiving data from the OI may be being corrupted, thereby locking in the last data frame instead of shutting down due to lost radio link.

I wonder if this may be a problem peculiar to your RC, only time will tell.

Re: does anyone have OI and RC radio issues
 

It's the 2007 RC, which I believe has v13 master. Waiting for a return call from IFI. Were getting a "no radio" on the OI. Shouldn't this cause the master to shut down, regardless of what the User processor is doing?

Re: does anyone have OI and RC radio issues
 

Correct, "no radio" should immediately stop the robot dead in its tracks.

Does it work fine tethered??

Re: does anyone have OI and RC radio issues
 

Spoke with the fine people at IFI. Best guess is it's either a bad cable, or interference from another radio source. There is a half second delay after the last good packet before the robot shuts down. After a good packet is received, the counter is reset, causing an additional half second delay. Hopefully we can narrow it down tonight.

Gamer930,
We have not seen it happen with the robot tethered. It only happens intermittently on the radio.

Maynard

Re: does anyone have OI and RC radio issues
 

we were using the 2006 oi and rc with the new radio's from 2007. Is there a difference with the 2007 oi and rc? we are going to try and run tomorrow with using the 2007 oi and rc and see if there is a problem.
when we lose the radio signal on our oi, the robot stall and shows loss signal also.
cant see how it would be intereference. nothing else around and we have always tested in the same room.

anyone? please help.

Re: does anyone have OI and RC radio issues
 

To the best of my knowledge, the 2006 and 2007 systems are identical hardware. But the 2007 RC came with v13 of the master code installed, which has specific support for the new radios. If you haven't yet updated the master code in your 2006 RC, that might be an issue.

(To check the master code version, press the mode button on the OI until it shows the 3-digit user value. The display will show the version number briefly before changing to the user byte value. You want to see u013 appear.)

Re: does anyone have OI and RC radio issues
 

We're still seeing this problem. After talking to IFI, we tried the following.

1) replaced both modem cables
2) tried using other channels
3) moved the rc modem away from power sources
4) switched to the 2007 OI (shouldn't make a difference)
5) loaded default code from IFI
6) disconnected the power on OI to test 1/2 sec timeout (passed)

Still seeing intermittent modem losses. We did discover the RC is losing the link first. Sometimes it recovers before the OI realizes there is a problem (never see a modem light on OI).

waialua359,
I suggest you contact IFI. It could be an unrelated issue, but it sounds very similar.

I'll call IFI again when the sun gets a little further west.

Maynard

Re: does anyone have OI and RC radio issues
 

Maynard,
The condition you describe can be a power issue to the OI. Does the modem cut out when the robot is just sitting there or does it cut out when moving? There is also a possibility in antenna location and orientation. Is it possible to take a picture of the modem mounting without sacrificing team secrets? Is the radio mounted near a motor, particularly an FP or Mabuchi? Does the modem cable run near wiring that feeds any motors?

Re: does anyone have OI and RC radio issues
 

The modem was near the main breaker. We moved it away, but perhaps not far enough. What would you consider a safe distance. We're running four CIMS on modified AM gearbox. Although it's difficult to say for sure, it generally seems to be under power. However, it also happens with the robot on stands, with little load on the motors (free wheeling). Sorry, don't have access to the robot now, so can't provide pics. It's still in the prototype phase (controls screwed to plywood). We'll try moving the modem a greater distance tonight.

Maynard

Re: does anyone have OI and RC radio issues
 

Maynard,
Being near the main breaker is usually not a problem, having the antenna itself near metal objects will detune the antenna and make it inefficent. Spark noise from the brushes can wreak havoc with the modem and usually unloaded motors produce more noise than normal loads so being up on blocks would produce as much or more problems than driving. It also may be the way the robot is wired. The power for the RC should come from the first breaker on the multi position breaker panel. Make sure that all connection to the RC are tight. Finally, and I should have mentioned this before, you need a fully charged Backup battery connected to the RC. The NiCads come discharged so you need to charge them at least ten hours out of the box. The backup holds up the radio modem during times the RC shuts down for low voltage.

Re: does anyone have OI and RC radio issues
 

Thanks for the help Al,

The modem is about one foot from one of the gear boxes. We'll try mounting it on a mast tonight. I'm quite sure our wiring is correct, but we'll double check it as well. We're servo shifting, so I am sure we have a charged backup battery.

Maynard

Re: does anyone have OI and RC radio issues
 

It wouldn't coincide with the shift point would it? Are the servos having a hard time shifting? Try without shifting and see what happens.

Re: does anyone have OI and RC radio issues
 

We loaded the default code, which did not have our shifting code. The servos were unplugged and we simply drove back and forward in a straight line. A failure occurred with 30 seconds. We'll also try leaving the robot idle to see if we get the failure.

Thanks
Maynard

Re: does anyone have OI and RC radio issues
 

OK. I just checked the version and it is the u012 version. i used this years mplab to get the default frc code. how do i update to version 013. Does anyone know if its the reason it would cause radio, no modem failure?

Re: does anyone have OI and RC radio issues
 

We have experienced the same problem. Even after following all the rules and guidelines provided by IFI and some of you folks, our radio randomly decides to stop working, and sometimes the robot will still keep going for a while (Maybe half a second, but thats enough to break a few bones). Some folks reported the same problem at Ramp Riot where the newer radios were tested. I really hope IFI looks into this and corrects this problem. It would be extremely frustrating to have a bug stop us from programming to our fullest like last year.

Re: does anyone have OI and RC radio issues
 

Just got off the phone with IFI. There shipping us new modems to try.If your seeing occasional modem losses, be very careful. We lost control of the robot at 15 fps. While the robot is supposed to shut down after 1/2 second, ours traveled around 30 feet before it met it's first obstruction. As they say, "The rest is history".

Bharat
If you have any 06 modems, IFI said the should work with v13 master code.

Maynard

Re: does anyone have OI and RC radio issues
 

We are having the same issue... We checked all the wiring, and its definitely the radio cutting out. I'll be interested to see what the results are.

I have to wonder if it has to do with the housing... the housing is far to large for the board as far as I can tell, and when you shake it a little, you can hear that it isnt braced much against the casing.

Re: does anyone have OI and RC radio issues
 

Now what happens if IFI determines it is the new radios or the whole RC kit to be defective. Will they ship new kits out to all teams or those with the problem. If they don't plan on shipping to the teams does that mean teams need to prolong the programming which usually is the last phase of building and pick up new kits when they get to their first regional? I have always known the lost of signal for the slightest amount of time was caused by power issues and interference, so I don't think it has to do with programming all though the simplest of things can cause the greatest of problems. Something to be kept up to date on. If i set up the 2007 Kit (RC & OI Stuff) and plug everything up would there be a chance of getting the same problem or does the RC need to have motors and such be attached before you see any radio issues?

Re: does anyone have OI and RC radio issues
 

That's what the kids did. I am not sure of the results but I hope one of them can post about it here soon. I am assuming IFI will at least put more reliable modems at the competition, but for now, we must live with what we have. I am not sure how rookies will take this as they have no older modems. Autonomous programming and testing purely on a tether is kind of hard.

Re: does anyone have OI and RC radio issues
 

wow! and I thought we only had this problem. Im surprised it didnt come up earlier with a lot of other teams. I guess we are lucky to have a drivetrain already with some functions.
Anyways, its confirmed that when we use our 05 or 06 radios, our 2007 robot works! But by only changing to the new 07 radios, it shuts down intermittently!
can someone confirm that the u013 code will work even with the older 05,06 radios. I didnt want to upgrade, only for it to not work. If that were to happen, then we would be stuck with using the new radios that dont really work well right now.

Thanks in advance!!:D

Re: does anyone have OI and RC radio issues
 

According to IFI v13 should work fine with 06 modems, and I believe 05 are the same.

Great to hear it solved your problems. We haven't tried the old modems yet.

Maynard

Re: does anyone have OI and RC radio issues
 

IFI is sending us new tested radios for us to see if they work properly on our robot. Cory was gracious enough to do this free of cost.
We are sending our old ones back.
This is a request similar to team 1276 also.

Re: does anyone have OI and RC radio issues
 

its now confirmed 100% that our radios are having issues. IFI has not posted an answer to my question yet because they are still investigating the issues.
If anyone has similar problems, please post.

Thanks,
Hawaiian kids

Re: does anyone have OI and RC radio issues
 

We should get our radios today. IFI has been great to deal with and very responsive. Sure makes a difficult situation a little easier.

Maynard

Re: does anyone have OI and RC radio issues
 

IFI told me this morning that they will want to investigate your radios when you send them back. We are sending ours back already also.

Re: does anyone have OI and RC radio issues
 

Ok I have a few questions and maybe I should post them on IFI's Forums but I'll give here a shot first:

1) All though a few teams have come forward and made the rest of us aware of the OI & RC Modem problems - Does this effect all the teams radios?
2) Is there a way to find out if your OI & RC Modem is defective by just plugging everything in as far as joystick or 2 / power / maybe a speed controller & a victor - Basically not setting up completely but enough to get everything talking and making everything look like its under joystick control or does the control system need to be completely setup?
3) Should teams just go and contact IFI and talk with their representatives under the assumption that the OI & RC Modems are defective w/o actually hooking everything up and finding out first.

Re: does anyone have OI and RC radio issues
 

Team Update #6 seems to address your concerns -- looks like IFI is working on it.

Re: does anyone have OI and RC radio issues
 

Ahh see this is the end result of me not keeping up on the team updates thanks for pointing that out i'll go ahead and download the update

Re: does anyone have OI and RC radio issues
 

As of now, of the 4 teams participating in Hawaii, Team 368 has also tested out their RC and OI with the new radios. After talking with them last night, they have not encountered any problems with the radios so far.
It seems that since there has not been too many teams posting problems here, they either havent tested them yet, have no problems with them, or havent read this post.

Can anyone who has tested their 2007 radios post if they DO work OK?:D

Re: does anyone have OI and RC radio issues
 

Well, I have my own comment to add to this issue.

1075 got the 07 system set up on a bot tonite, and I IMMEDIATELY noticed alot of lag in the system... soon after that, i realized it was the radio cutting out on me. Sounds EXACTLY like what you're saying, the Master chip isn't shutting the bot down on radio loss... this is rather distressing to take your hands off the controls and the robot doesn't stop.

Our first thought laid the blame with our placement of the radio... it is within a few inches (read 4-6") of two CIM motors. After reading this, I think maybe the blame needs to be laid on the v13 master code, or the new radios.

Edit: We were using the 07 RC / 07 OI / 07 Radios

Re: does anyone have OI and RC radio issues
 

I really dont think its the master code. we encountered the problems with the older u012 and u013 codes alike. We used three different robots, including this year's robot base and tried all the likely scenarios to try and pinpoint the source of the problem, including orientation, location, etc. the new master code worked perfectly with our old radios also. Unless, the new master code is geared towards the old radios??

Re: does anyone have OI and RC radio issues
 

Our FCC ID for our RC is UKU-RC01.
Our FCC ID for our OI is UKU-OI01.

Re: does anyone have OI and RC radio issues
 

fcc exibits on the lisence
OI. Modem https://gullfoss2.fcc.gov/prod/oet/cf/eas/reports/ViewExhibitReport.cfm?mode=Exhibits&RequestTimeout =500&calledFromFrame=N&application_id=606267&fcc_i d='UKU-OI01'

RC. modem
https://gullfoss2.fcc.gov/prod/oet/cf/eas/reports/ViewExhibitReport.cfm?mode=Exhibits&RequestTimeout =500&calledFromFrame=N&application_id=642706&fcc_i d='UKU-RC01'

Re: does anyone have OI and RC radio issues
 

we have a problem with our oi and rc, i got it to connect and we were all happy, but when we went to power it back up, it just didnt want to work. ifi has not posted anything yet about the problem but i hope they fix it, the robot workes in teather mode

Re: does anyone have OI and RC radio issues
 

Ran the replacement modems today for nearly an hour without any failures. With the original modems we never went longer than 10 minutes with out a loss of signal. While we still need to test them further, it's very encouraging.

Maynard

Re: does anyone have OI and RC radio issues
 

Team 1501 is also having the same problem. We have already experienced things like the disbale not wokring when it should etc. When it was first rbought to my attention and i was testing it we let go of the joysticks and the robot did not stop until it scooted a table a good 2 feet or so.

We usually try to have extra radio modems, victors, and spikes, so when the radio modems come in we will switch them out and see what happens.

*EDIT
I wanted to add that, we had a problem simular last year. We had came to the conclusion that it was static electricity coming through a custom cable. Once the cable was removed off the robot, we didn't have the problem again.

I have also seen (as mentioned elsewhere in this thread) the robot do this when the backup battery gets low. I did not think of the frame and the antenna being close together as causing a problem, but will check on that.

So far we have tried a bunch of things. While it has only happened a few times, when it does happen it goes on for a little bit. I think the last time I seen a problem was 2 or 3 days ago

*EDIT

Re: does anyone have OI and RC radio issues
 

I hope we get the new ones today so we can test them out.

Maynard-is your radios still working without problems?

We will post whether our new radios work once we get them.

Re: does anyone have OI and RC radio issues
 

It was Saturday we tested them, and we did not meet Sunday. Not sure how much we will run them tonight. We spent over two nights trying to resolve the problem before we got replacements, so we're playing catch up. I'll let you know how it goes.

I shipped the old modems back today.

Maynard

Re: does anyone have OI and RC radio issues
 

From another thread on this subject...
Any merit?

Re: does anyone have OI and RC radio issues
 

I am not sure how many people are having problems with the OI and RC, but from what I can tell we are one of the few unlucky ones. I think we will be contacting IFI soon about our glitches. Namely, the robot running several seconds after it drove into our makeshift player station. It's nice to see that they are doing something about this though.

Good Luck to all of you and I hope that not everyone is affected on this one.

Re: does anyone have OI and RC radio issues
 

cell phones are not the issue that's for sure. However, we have yet to try our new radios yet since we were powdercoating parts of our robot.
We will try it today and see if IFI has fixed our problem.
Again, I will keep it posted once we find out.

Re: does anyone have OI and RC radio issues
 

I wonder if this problem only affects random radios, or if it's every single radio.

Re: does anyone have OI and RC radio issues
 

Team 1511 has experienced the OI/RC radio issues as well for the past 2 weeks. Same symptoms of cutting in and out for a period of a few seconds, as well as the master disable switch on the competition port NOT killing the robot as it should.

I contacted IFI over this past weekend, and spoke with Corey Chitwood, who was extremely helpful. We had a discussion regarding potential RF interference issues, internal vs. external antennas, and we tried a few of his suggestions. From our discussion on Saturday morning, there is not a mass recall or swarm of teams reporting problems (yet). He mentioned the teams who have posted above this, and said that they found and fixed a clear hardware problem on the very first team to have sent their radio back. At that time, he had not received the other radios that were RMA'd, and couldn't provide any additional info.

We tested extensively on Saturday and Sunday, both in autonomous and manual drive modes, and continued to experience radio cutouts. After nearly squashing a mentors foot with a speedy autonomous (and un-killable) robot, we reverted to last years radios. I obtained a RMA from IFI on Tuesday afternoon, and our modems ship out Thursday morning.

When we receive our new ones I'll post an update regarding their performance.

--Eric

Re: does anyone have OI and RC radio issues
 

Well, our team has not yet contacted IFI, since we usually order an extra set of radio modems we were going to wait to see if those worked. But they have been out of stock for quite a while. Our problem from what i have seen and heard does not happen all the time it is quite random. But having a robot with no control even for a few seconds can be bad.

I'll post if i have any news

Re: does anyone have OI and RC radio issues
 

We decided to do a double process tonight. We broke in our transmissions and tested our modems. We had the controller on one side of the class room and the RC on the other.
We used the trim on one joystick to drive both motors via the "single stick" drive mode.
Randomly the motors would just stop and restart, indicating that the data comm. had dropped for a sufficient amount of time to cause a timeout. While observing the RC, it became obvious that the Radio Modem light would flash RED when ever the motors would stop.

We will be contacting IFI in the morning to report the problem and await further instructions.

Re: does anyone have OI and RC radio issues
 

While cell phones do not operate on the same frequency as the modems, they are capable of some high signal levels that could cause local inteference which could cause the radio modems trouble. It is one of the reasons that wireless communication is not allowed at the playing field.

From section 3.14.3 Pit and Competition Safety

Two-way radios: Not allowed in the Pit or near the playing field since they may interfere with robot operation and cause accidents.

Re: does anyone have OI and RC radio issues
 

If our new radios continue to have problems, I plan to run a poor man's RS103 test (1 V/m, 30MHz-9GHz) in a 3m shielded room to see if I can cause the problem to crop up at a specific frequency range. I might be able to push the field strength with some hacking up to 5 V/m from 1-8GHz, which includes the cell phone band.

For the interested reader, RS-103 is part of a battery of tests performed under MIL-STD-461D (the new E is very similar) for military qualification of electronic products. Commercial products rarely need to meet a susceptibility requirement, other than the generic FCC Part 15 statement for intentional radiators that says they "must accept any interference caused by the legal operation of other radio services".

I suspect no one is really interested in EMI though :( :(

Re: does anyone have OI and RC radio issues
 

Esqaured,
The modems operate in the 918MHz FRC band. So most cell phone interference is from cell phones operating just under 900 MHz and obvious FRC radios and Ham operators in the adjacent band. I suspect you might find that interference is not as big a problem as the AGC overload caused by nearby signals forcing the input gain down.
Please check for EMI as well, I think it will prove to be useful data.

Re: does anyone have OI and RC radio issues
 

I should have been more specific in my previous post, the medium power amplifier I will try out has a spec'd frequency range of 1-8GHz, but continues to exhibit reasonable gain and output power specs for another 2-300MHz below it. The 5V/m is my best guess at effective radiated power at these "unspecced" frequency ranges.

You've got an excellent point about AGC (Automatic Gain Correction, which in RF systems is intended to avoid saturating your receiver, which leads to data that all looks like the same, far too high level). To test this, I'd have to crack the case on the modem, and somehow I doubt our team leader will go for this :ahh: Anyone void their warranty and see how they implemented this year's radio?

Another possibility: I've seen front-end bandpass filters that had poorer than expected rolloff outside the band, resulting in a susceptible front-end. Since the hardware repair to the first team's radio was relatively quick, replacement of a poor quality filter would fit into this category. Additionally, it may not be an issue with all filters, so some teams could be operating just fine.

In the end, I expect this to be similar to last year's 8.2V problem where some teams had it, some didn't. Very similar in that both resulted in non-responsive or potentially destructive robots!

Re: does anyone have OI and RC radio issues
 

That's interesting. How about the old radios? Is there something in its makeup where cell phones dont have a strong enough signal to affect them.
I made that statement earlier based on an earlier post, then had our whole team use their cell phones near the robot with our old radios. It didnt encounter any loss signal between the OI and RC.
What's different internally with these new radios?

Re: does anyone have OI and RC radio issues
 

E,
I kind of doubt there is great filtering on these radios due to the low cost of the item. My guess is the T/R filtering is about all there is with a little additional low pass to cut the 2nd harmonic down to spec. What we don't know at this point is how great the shields are inside and your testing might show that.

waialua,
We don't know enough about these radios yet to answer your questions. The reports of failures from teams on CD do not tell the whole story. There are far too many variables to point to one thing. Let's just hope that IFI will take care of this as they have in the past.

Re: does anyone have OI and RC radio issues
 

Eric,

Pictures of the radio's internals are part of IFI's FCC OET, EA public file as is the emissions test report performed on a prototype unit.

Based on my own observations of the problem, an Electrical Fast Transients test, such as EN 61000-4-4, might be more revealing than an RF succeptability test, but certainly a lower frequency, 100% AM modulated signal can reveal problems that an EFT test would also expose.

Again, without motors running, we saw no indication of packet loss.

Our build location is surburban with no close field radiators, let alone any dynamic radio transmission that would be tightly coupled to motor actuations.

Re: does anyone have OI and RC radio issues
 

that just went right over my head??

Re: does anyone have OI and RC radio issues
 

I appologize if some of my references or terminology was confusing to others. My intent was to respond to Eric's proposed test and to answer a question as to the 'what's inside' question.

Eric suggested that he was going to run some high(er) frequency RF succeptability testing, and I suggested that, based upon my observations, that the problem might be easier to expose by subjecting the device to lower frequency pulsed transients.

EN (EuroNorme) 61000 describes a number of different product compliance tests, and among them is a specific fast transient test where interconnecting cabling is laid in a coupling trough and subjected to this test.

I also stated that a lower frequency AM (Amplitude Modulated) signal can sometimes expose weaknesses with a given product design that a transient test will expose.


As to the FCC (Federal Communications Commission) OET (Office of Engineering and Technology) EA (Equipment Authorization) reference, if you look on the back of any unlicensed device which intentionally generates RF (Radio Frequency) emissions, you should find a manufactuer and product code identifier. With that identifier, you can look up information regarding that specific device, on the FCC's website, as that information becomes part of a public file. The direct link to this information was provided earlier in this rather lengthly thread, so I didn't see the need to re-post it.

I think it is unfair to IFI that we publicly speculate as to what the root cause of this problem is, or is not, without factual information in hand. However, as someone experienced with product design, including RF design, I will state that I do not believe that "cell phones" are the problem here. As I indicated in my response, our build location is not located near any RF sources (i.e. transmitters), let alone any that would be synchronized in time with the actuation of the motors.

Ultimately, whatever the cause of the problem affecting a few of us may be, the responsibility to resolve it lies upon the manufactuer and or FIRST to work out a solution. Those among us, such as Eric, with equipment to perform testing that IFI may not otherwise be able to accomplish on their own, may be able to provide some additional data to IFI that would help them.

I hope that helps,

Re: does anyone have OI and RC radio issues
 

How about a machine shop, given the number of different types of equipment and such in a machine shop, would any of that equipment be enough to disrupt RC to OI communictaions for a few seconds? Same goes for a wood shop?

Re: does anyone have OI and RC radio issues
 

The comment about cracking the box was in regard to seeing if the automatic gain control (assuming the IFI RF frontend was using this) was kicking in to some unknown response. With a few oscilloscope leads we could check to see if this was occurring.

We performed no lab testing before shipping the modem back, so other than some more recent comments about potential motor interference the only thing I had to go on was the cell phone comment. It seems unlikely to me as well, but if I'm scanning at 30MHz it's just as easy to let the equipment continue up to 900MHz. Our Biconilog antenna is good to 1Gig, and somewhat shoddy to 3Gig. From 3-9 I've got a log antenna, and past that you'd need a horn which doesn't calibrate well for the 10m FCC testing we typically perform.

I'm pretty limited in the EFT testing I can perform, however we have some loops lying around that might work, albeit in a completely non-calibrated fashion. Certainly anything I try in that realm will be pretty non-scientific.

If IFI chooses to end speculation after a few more radios have been in their lab, that would be fantastic. Like last year's 8.2V problem, there were some intelligent discussions trying to determine what the problem is. The more people with something useful to contribute looking at the problem, the better.

Ninja Edit: Thanks for filling in the details of our acronym-laden conversation Dave. I tried to give some detail to my earlier posts so this doesn't lose meaning to others following the thread.

Re: does anyone have OI and RC radio issues
 

E and Dave,
I went to the FCC files and looked over the pictures. Anyone else notice the internal antenna? Is it a dipole with the external antenna or a separate transmit or receive antenna?
I would like to know how many teams having problems have the modem mounted against a metal surface. If any team is having regular problems, could you try holding the modem outside the robot and check for same issues you had when the modem was mounted on the robot?

Re: does anyone have OI and RC radio issues
 

They're definitely separate antennae, one for transmit one for receive. During my discussion with Corey this past weekend, some of his suggestions were to mount the modem vertically, orient the external antenna away from the internal antenna, and to keep it away from any metallic structure nearby that could be acting as a ground plane. At the time, both modems were screwed to pieces of plywood, one for the driver station, and one that was C-clamped to our drivetrain with no structures surrounding it. Implementing those suggestions still resulted in a number of cutouts on Saturday afternoon and Sunday.

IFI should have our modems on Tuesday assuming UPS does its job. Right now, last year's modems are working flawlessly so paying double or triple for to overnight them wasn't worth the cost.

--Eric

Re: does anyone have OI and RC radio issues
 

Eric,
Did Corey indicate which antenna was the transmit?

Re: does anyone have OI and RC radio issues
 

I dont think this would be the problem. We work in GM and the WHOLE machineshop is around the corner, we havnt had any problems with the radio as of yet. So maybe it just might be your connections or something other thats simple. Maybe your radio has been brainwashed by another team not to work? :ahh:

Re: does anyone have OI and RC radio issues
 

Nope. Without knowing more about their link budget, it's not immediately clear which should be which.

Judging from the photos and clever use of MS-paint, the internal antenna is roughly 1/4 wave, and the external roughly 1/2wave for the 902-928MHz band. Assuming no poorly placed metallic structures, and that you aren't purposefully pointing the antennas end-wise at each other, you should get a nice fat pattern off both. Once again, for the interested reader, RFCafe has lots of fun info about antennas, power, patterns, etc. IN particular, check out http://www.rfcafe.com/references/ele...a_patterns.htm

I've got to hand it to the IFI RF guys though, they tuned their transmit strength to be JUST under the FCC limits. Particularly on the RC side :) If there is a signal strength problem, it's not on the transmit side.

I'd say those are my 2 cents, but at this point I'm up to about a buck's worth.

--Eric

Re: does anyone have OI and RC radio issues
 

So beyond a relocation of the mounting of our radio, 1075 needs to phone up IFI and ship the radios back? They seem to be much less reliable than the old Ewave models... I'm not sure why we switched either, considering Ewave engineered those radios FOR us. Our old radios were rebranded Ewave Screamer422s for reference, Ewave's website even states that they were specifically designed for us.

Re: does anyone have OI and RC radio issues
 

If you have the same problems other people in this thread have shown, you've tried mounting them vertically, and not deep inside your robot, then call them up and get an RMA. Since so far there isn't a mass posting of "my radio doesn't work", if you don't have any problems I wouldn't send it back.

Re: does anyone have OI and RC radio issues
 

The parts adjacent to the shield appear as though they might be the first and 2nd IF filters, probably 455kHz and perhaps 10.7MHz or higher, and are only stuffed on one of the boards. So my guess would be that the internal antenna is Tx, and the external is Rx. It seems odd they wouldn't just diplex the external antenna.

As to the Tx power, I was a bit surprised to see that was considered passing and do note a "unc." in the pass/fail column but saw no discussion on it in the report... but certainly that is not a problem for us to consider here as the error is potentially on the side of a tiny bit too much power.

I have my doubts that this is a link budget, antenna tuning, external interference (cell phone or otherwise) issue, but speculation and facts are two different things and IFI is in the best position right now to analyze the facts.

Thanks,

Re: does anyone have OI and RC radio issues
 

Correct, and I'd like to echo that as well, and in part is the reason why I started a new thread, so that we could be very clear that IF you have a problem as some of us have described, that you need to contact IFI and discuss the situation with them, and if they determine that it is necessary, to RMA the unit back to them.

As of Monday this week, only 2 of the 4 teams reporting a problem had sent in their radio's for examination by IFI. I overnighted our teams radios to make that 3 out of 5.

The burden falls upon IFI and FIRST to determine how to address this issue and whether or not it is something they feel warrants additional attention.

As with last years problem, with what I think was a silicon bug in the user processor, that was worked around by a change to the linker file, some people had experienced the problem and others had not. IFI and FIRST were proactive in making sure that by competition time, all teams had been given the information they needed to make the updates, and I think we should be confident that the same level of effort would be applied to this problem, IF (and I must stress IF) this is later determined to be a problem that potentially affects everyone.

The FUD factor (Fear, Uncertainty, and Doubt) might be running a bit high here, but logical thinking will resolve whatever this issue may be, which again has only been reported by a few teams.

Thanks,

Re: does anyone have OI and RC radio issues
 

all of IFI's suggestions were tried for our robot. Ex. mounting radio's vertically, away from suggested places, etc. Still the same problem.

Hopefully we will all find out soon the specific(s) on what may be causing these symptoms.:D

Re: does anyone have OI and RC radio issues
 

Team 359 UPDATE!!!
We finally tested our new radios from IFI. We tested for two hours with 3 fully charged batteries.
NO. of problems with radio during that time.........NONE!!!!!!!!!!!!!!!

Our conclusion is whatever technical possible reasons it could have been, simply put, the ones that came in our kit was defective, and the new ones that we got work PERFECTLY. Not one time did we lose signal between the OI and the RC.

I hope its as simple as everyone else who have similar problems, to have their radios replaced.

Aloha!:D

Re: does anyone have OI and RC radio issues
 

i was being really stupid and desided to look at the ifi site for information, and came across the manuel. i might have found the reason for ours not working. cuz when we did it like the manuel said it worked, so might be the error on my part. *slaps self across the head*

Re: does anyone have OI and RC radio issues
 

The Nemko lab I've worked with in Canada has an uncertainty of around 1-2dB for their 10 meter site. It rolls up all the uncertainty in the site, antenna, cables, equipment, etc. Anything less than that uncertainty number means they have to put Unc. in the pass/fail, but it doesn't stop you from passing.

Re: does anyone have OI and RC radio issues
 

Team 179 is also having intermittent loss of connection. It is constant and when it loses signal it takes <10 seconds to come back. It is mounted visibly and away from other components.

Re: does anyone have OI and RC radio issues
 

I would send them back. that fixed our problem when we got new ones. seems to me that their must be some defective component when the initial batches were made and sent to teams during kickoff.
Just my guess.:yikes:

Re: does anyone have OI and RC radio issues
 

I can't find the manual, can you post a link to what you found please??

We're seeing some funny stuff, but have NOT actually done any troubleshooting, nor have we confirmed that there actually IS a problem. We'd like to check that everything si correct before jumping to any conclusion.

Don

Re: does anyone have OI and RC radio issues
 

ysh sure, here it is

Re: does anyone have OI and RC radio issues
 

I went to go help my old H.S. Robotics Team and one of the things I did today was test out the 2007 Robot Control System Package - I hooked it up to a 2003 robot using the default program that was already loaded onto the RC and unfortunately they too have bad radios. At first I thought it was a dead battery dropping the communication so we changed the battery and I kept a very sharp eye on it and when it would lose connection the battery registered +12vdc so we eneded up ruling a battery problem and wiring problem right then and there. Next we moved to a secluded room and still had issues and came to the conclusion that it was the modems. I did contact IFI & left a message with the voicemail but I would like to know is there a specific number you guys called other than the ones on IFI's Tech Support Link? The sooner we can get some new radios the better. The only thing I didn't try was the 2006 modems and I am not up to the challenge of dismantling a robot to get to it.:ahh: One thing I noticed about the Communication Link being lost was that it was happening extremely rapidly no more then 30 secs apart and lasting up to 15 secs without a link. The good part was when the link died so did the robot even though the OI & RC registered as still being connected so thankfully no one was harmed and nothing was damaged.

Re: does anyone have OI and RC radio issues
 

Has anyone following this thread tested the new v14 Beta version of the Master Code as mentioned in Team Update #8? It was created to remedy this problem.
I will attempt to test it tonight when I get to the school and post our results.

Re: does anyone have OI and RC radio issues
 

we've had some similar things, but only for the short term. after disabling the robot goes for about a second, and then stops what's up with that?

Re: does anyone have OI and RC radio issues
 

I was unawair of the upgraded master code I will have to d/l it into the RC tomorrow afternoon but me personally I think it may be a hardware problem more then a software problem.:eek:

Re: does anyone have OI and RC radio issues
 

I believe there are actually 2 problems here, and I suspect the new RC code only addresses one:

1) Dropouts in the communication link between the modems

2) RC continues to run on the last information received for a few seconds when the link drop occurs

My guess is that the new RC firmware addresses the second issue but not the first. We loaded it on Saturday but due to not having a fully-charged battery available and some other issues we're reserving judgment until we do more testing tonight. It definitely did not fix the communication loss, however. We saw the red "No Data/Radio" light on the OI at least a few times a minute, usually lasting about 2-3 seconds.

{edit} Another question that I don't remember seeing: has anyone else noticed quite a bit of latency with the new modems? We were experiencing about 1/2 second delay on any controls from the OI before the RC responded. Tonight I will compare the new and old modems to see if the new modems are responsible for this as well, but I'm curious if others noticed this too.{/edit}

Re: does anyone have OI and RC radio issues
 

Hey, guys. Just another team to report the same problem with losing radio connection. We've had it for as long as we've been running, but until Saturday, we haven't been actually driving and operating for an extended period of time. Also, I originally thought it might have to do with how we mounted our RC board. The opposite end of the power distribution rail is mounted close to the RC ports, and you have to apply a decent amount of pulling pressure upwards to plug into them. Originally, I thought this was the problem, but today, I opened up the RC, to check for problems, which I could not find. I also remounted the RC to avoid the pulling, as well as tested the radio cable and tried several different ones. We also tried moving the radio away from the motors and electronics, and positioning it many different ways. Nothing helped, and we still have the problem.

Logically, it seems like it has to be a hardware problem, in either the RC or the radio itself, not a signal interference problem. When the connection loss occurs, I notice several things. Firstly, the radio light on the RC turns red, which normally indicates a lack of any radio at all. And yet, the radio itself still has power. Also, the OI always shows that there is a connection present, despite what the RC light shows. And yes, we also have the continuation of the last command, for a short time.

In addition, I know that we have the master code v13, because I went through each of our RC processors and ensured that the newest version is installed. And yes, we are using all new equipment both on the robot and on the control console.

Does anyone know how many teams have actually reported this problem? I plan to contact IFI tomorrow as well and add our name to the list.

Re: does anyone have OI and RC radio issues
 

It seems that more and more teams are having those 2 issues as more teams test.
Once again, we tested at least several different occasions already with our new radios from IFI with NO problems yet.
But also, Unless you have problem #1, how would we be able to fix problem#2?
I agree with team 111, IFI more than likely solved the software issue, but not the hardware issue (problem #1).:D

Re: does anyone have OI and RC radio issues
 

Actually, it's not a nationwide problem. There are a large number (majority) of teams who are not experiencing issues. I'm sure IFI will work to resolve the issue for those affected, as they have time and time again. Normally, I'm one to get into a panic about these types of issues, but not this time. IFI has kept the robots running on the field since the year 2000, I have complete faith that they'll work through this issue. As has been said time and time again, if you are one of the teams affected, contact IFI and they will help you get things resolved.

Re: does anyone have OI and RC radio issues
 

As a follow-up from our testing tonight, here's what we found:

• The connection was very unreliable for us, just as others have noted. A multi-second dropout occurs every 15-30 seconds while driving (even when not under heavy load). Does not appear to be a battery issue to me (fully charged battery and backup battery, and voltage on the OI looks good).
• The "run on" problem didn't seem apparent, but now the problem is opposite: every time there's packet loss the robot shuts down (triggering single-action solenoids to de-activate, stopping the drive motors, etc). Basically, if the robot doesn't have data, it has two choices: keep doing what it was doing for a bit, or play it safe and shut down. Obvious safety concerns exist with the first (and what was seen in R13 firmware), but serious performance issues exist with the second (as seen in R14).
• I confirmed that the new radio modems add significant latency. There's probably 300ms of latency with the new modems. Switching to the old modems eliminated this. I think this will be quite a hindrance to drivers (though I imagine they will mostly adapt and have to predict movements more).

I'll be contacting IFI tomorrow with this information.

Re: does anyone have OI and RC radio issues
 

Lets make things clear.

Two problems were discussed here today.

1, V13 repeating the last code, for an extra few seconds.
2. Defective Radios


1. With the V14 Beta update this problem should be fixed.
2. It seems that a few of these new radios this year actually have some kind of defect in them.
Lost Packets / No Radio as if it was getting interference or something was blocking the signal. After you have performed all the normal maintenance is when a call should be placed to IFI. The wonderful people at IFI are sending out tested replacements.

Re: does anyone have OI and RC radio issues
 

I have not yet encountered a radio that will remain functioning for more than a few seconds without cutting out

Re: does anyone have OI and RC radio issues
 

We tested our radio out today, and had a very unreliable connection the entire time. At one point in time, when trying to drive the left side forward, the right side went backward and continued to after disabling.

Re: does anyone have OI and RC radio issues
 

Our radios have problems too. They cut every 10 seconds or so, and then reconnect.

Jacob

Re: does anyone have OI and RC radio issues
 

SOOOOOOOO, if the new beta code supposed to resolve the problems, how come we never downloaded it and our robot/radios work fine now?
The ones that came in our kit was "defective" and by just getting new replacements from IFI, it works fine now after hours of testing.
Seems to me there are more variables in what the problem could be.
Anyways, if it aint broke, why fix it at this point for us.:D

Re: does anyone have OI and RC radio issues
 

On the other hand, I had been using it without incident for a week when working with the camera on last year's drive base, and it behaved itself just fine this evening while I was twiddling with the joystick response. (I was running the OI from one of the old drill batteries for portability tonight. I wonder if that has anything to do with it.)

The only oddness I have noticed with the new radio modems is the time they takes to sync up when first turned on. The old radios found each other within a second or two; the new ones take closer to ten.

Re: does anyone have OI and RC radio issues
 

that is TRUE! we noticed that also that it takes a while for them to link up together.
great observation.

Re: does anyone have OI and RC radio issues
 

Is this still true for teams who have received new radios from IFI, or who don't have this problem at all?

Re: does anyone have OI and RC radio issues
 

There is one confirmed response from waialua who had the issues we've all reported, sent his back, got them back from IFI 'repaired', and they now have no issues. There are 2 other teams who I know have sent theirs back (my team, and team 930). Dave K. from 930 will hopefully have his back this week, and update us if his work.

Our radios should be at IFI today, as soon as I hear back from them I will update the thread with what the problem (if any) was. By the time they're back in our hands, our robot will be complete and we'll be able to beat on them for a week or so to find out if they are fixed, and I'll update the thread then as well.

Now that there is v14 out, anyone here who still has their radios AND is currently having a problem, PLEASE post if it helps with either the robot continuing to run after a dropout, or the dropouts themselves. This will help IFI determine if their solution indeed will work across a number of different RC/OI/Radio/robot/motor/etc configurations, as well as other teams!

Re: does anyone have OI and RC radio issues
 

We saw this in one of our test drives. We discovered that our antenna was folded down into the frame of the robot. This shielded the antenna from smooth communication with the controller. It just lost contact for short periods of time and came back. Check to see if your antenna is being blocked by parts of your robot.