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View Full Version : Rumor or Real: RF Tether product


joe_balint
01-23-2005, 06:06 PM
Some of my controls guys have been hinting that there is an RF tether out there somewhere. I've been searching the forums for about 25 minutes and the closest I got was an old link to team696 selling 25ft and 50ft tether cables for the old pre2004 control systems. Does anyone have any more info on a true wireless-RF tether for the current IFI controllers? If so, I would appreciate the link or any contact info. Thanks. -Joe

Tom Bottiglieri
01-23-2005, 06:07 PM
Whats the point?

jgannon
01-23-2005, 06:22 PM
How would this differ from just hooking up an IFI radio to the Radio port?

Sscamatt
01-23-2005, 06:25 PM
Maybe you could beef it up to like 2.4Ghz and use it at competition.

steven114
01-23-2005, 06:47 PM
I would much rather use it as a wireless programmer :D

Sscamatt
01-23-2005, 06:50 PM
You can do it with bluetooth:
http://www.codebluecommunications.com/2nd%20Generation.htm

Expensive though, ~$300

Mike Betts
01-23-2005, 06:56 PM
Some of my controls guys have been hinting that there is an RF tether out there somewhere. I've been searching the forums for about 25 minutes and the closest I got was an old link to team696 selling 25ft and 50ft tether cables for the old pre2004 control systems. Does anyone have any more info on a true wireless-RF tether for the current IFI controllers? If so, I would appreciate the link or any contact info. Thanks. -Joe
The thread you are looking for is http://www.chiefdelphi.com/forums/showthread.php?t=31931

However, (1) you can not program the robot with a SMiRF and, more importantly, (2) use of any RF transmitter on the robot or OI during competitions is illegal under this year's rules.

We did purchase a SMiRF and we are using it for code development. It's cool! However, we will not be bringing same to our competitions.

dez250
01-23-2005, 09:51 PM
-All programming at competitions must be done via a serial cable from your computer to the RC.

-While in the pits there is no wireless communication allowed, that includes everything from your robot having to be on tether to test and the use of walkie talkie radios being "banned".

There are NO exceptions for these rules and must be followed at all times.

cdawzrd
01-23-2005, 10:15 PM
At one point, IFI was selling wireless program/debug modems... i dunno if you could tether with them, but you could program remotely. They seem to have discontinued them.

Dave Flowerday
01-23-2005, 11:04 PM
At one point, IFI was selling wireless program/debug modems... i dunno if you could tether with them, but you could program remotely.
Those could only be used to program the old PBASIC-based robot controllers. The new C-based RCs require a baud rate of 115200 bps for programming which the Stamper radios are not capable of (likely the reason why IFI stopped selling them).

russell
01-23-2005, 11:24 PM
I have been thinking about a way that one could reprogram the robot remotely using the provided radio modems. You could even do it in competition I think, though it would be so incredibly slow that there is no way you could download a whole program during one match. Basically, there is a way to use the radio modem to actually send bytes to the RC isnt there? If so you write your own dashboard type interface, which sends the program one byte at a time to the RC, which in turn uses the TTL port to give it to an external programming thingy. Then when the programming thingy has the whole program it goes and downloads it to the RC. I havent looked into what this programing thingy would have to be, but I know that one can get programmers for PIC microcontrollers which you plug into your serial port, and if you were to use the serial output ability of a PIC to drive the programmer, which in turn programmed the RC then you could do it. Like I say it would be incredibly slow. The other way would be to simply have an onboard computer which retrieves the user bytes from the RC then runs a modified ifi loader to download the program. Is it legal to put say an old 386 on our robot, and only use the RC for IO, and do all of the actual processing on the 386? If so how would we do the cost accounting stuff, as I dont think they exactly make them any more?

steven114
01-23-2005, 11:29 PM
Whether you can find rules allowing it or not, the benefits of reprogramming the robot in the middle of the match seem negligible. Much more useful would to be able to not have to hook the laptop up to the robot to program it...

sanddrag
01-23-2005, 11:31 PM
We've still got the 25' cables for $12 shipped priority. Add $2 for a small gender changer to get a female-female cable, in essence. Or you can use just the 25' M-F cable as an extension to your red F-F cable.

Upon request, we can get 50' M-F cables and 10' F-F cables. On the 50 footers, I am not sure about signal loss over the length. I know with a BASIC stamp it doesn't like to load code over a cable that long, but I haven't tried it with the Pic controllers. I am certain the 25' will not cause any problems in programming or tether on any controller.

http://team696.org/forsale.html

Mike Betts
01-23-2005, 11:52 PM
I have been thinking about a way that one could reprogram the robot remotely using the provided radio modems. You could even do it in competition I think,...
What part of R53 do you not understand? Wireless communications to or from the robot is illegal.

Anthony Kesich
01-24-2005, 12:02 AM
Whether you can find rules allowing it or not, the benefits of reprogramming the robot in the middle of the match seem negligible. Much more useful would to be able to not have to hook the laptop up to the robot to program it...

Our team has been looking at this. We went out and purchased a low profile motherboard with a PII on it and a flash card reader. We then bought a one gig flash card. We're gonna put this setup on the robot if we have the available weight (which it looks like we will this year). At the very least, we are going to use it for blackboxing and programming.

We would have a wireless card on it and run XP. This way we could run remote desktop, trasnfer over the code, and program through an Ad-Hoc network. Granted we would remove the wireless card before matches, but it would be very useful for testing code and quick changes to programming.

Even if the wireless wouldnt be allowed in the Pits (though i dont see how WiFi would interfere) it is still going to be useful for blackboxing and programming during build season.

-Tony K

Alan Anderson
01-24-2005, 08:23 AM
Basically, there is a way to use the radio modem to actually send bytes to the RC isnt there? If so you write your own dashboard type interface, which sends the program one byte at a time to the RC,...
The dashboard is a "listen-only" interface. You cannot send bytes to the RC using it. The only data you can control via the radio modem link is what the OI reads from the four joystick ports (and the two sanctioned pins on the Competition Port). If you want to send specific bytes, you'll have to control the joystick switch inputs to do it.

Mike Soukup
01-24-2005, 04:06 PM
Obviously not. If wireless communications to or from the robot was illegal then why is only 15 seconds of the match autonomous? Think this through. You push the joystick forward... The robot goes forward. How do you think the robot knows to go forward? (hint: the robot does not watch you with a camera and see when you push the joystick forward so it knows to go) Just for the sake of keeping this thread short I will just tell you. It uses this little thing we in FIRST call a radio modem, which uses what is commonly known as wireless communications to send and receive data to and from the robot. If you read my post, the system I described simply utilizes the perfectly legal connection that is already there. Sorry, Im getting sleepy.
I'm confident that Mike Betts knows what wireless communication is, he's been around FIRST competitions much longer than you have. Nor does he need a lecture on how FIRST robots work, he knows more than you do. The insulting attitude of your post was uncalled for and added nothing to the discussion. If you want to prove how smart you are by belittling Mike or anyone else, take it to PM or email.

And by the way, there is still wireless communication between the OI & RC during autonomous mode. Maybe you should get your facts straight before attempting to be a know-it-all.

Mike Betts
01-24-2005, 07:47 PM
Mike,

Thanks for coming to my rescue but it is not necessary... I have a pretty thick skin.

If anything, I am guilty of losing my temper (not a good thing)...

I just get a bit perturbed when people post on subjects which a passerby may interpret to be "cheating".

FIRST made it very clear that communications between the robot and operators must be exactly the same for everybody. This is why they do not give you the Master source code. This is why the dashboard is one way communication. And this is why no other communications device is allowed.

It is the spirit and the intent of the rule which is at stake here.

At least half of the teams have team members with the technical competence to install a two way communications device onto their robot and most would be able to make it so stealthy that a FIRST inspector would never find it.

At risk is the other half of the teams (mostly rookie) who read these threads and say "It's OK! Team 1430 is cheating so we can too!" or "I saw a post by Russell who says that this is legal!".

At risk is a mentor or sponsor backing away from a program like this because they do not want to be involved with less than ideal ethical issues.

At risk is what people like you and I have worked so hard at for so many years being undermined when people post about ways to circumvent the rules.

Thanks anyway...

Mike



Russell,

My apologies for snapping at you in my post. You are not the only person who is tired this time of year...

Regards,

russell
01-24-2005, 10:37 PM
Ok, now im in a much better mood and, apology accepted and returned.
And I guess my idea wouldnt work.... Unless you did like Alan said and used the digital or analog inputs for joysticks to transfer the program...(As if the other idea wasnt slow enough) Is there a rule against plugging your computer into the joystick ports? I am gonna look that up in a second, in the mean time I am gonna delete that other post. Sorry about that.

steven114
01-25-2005, 08:48 AM
You can't hook the computer up to the joystick ports - there is a rule (don't remember which one) expressly prohibiting this.

russell
01-25-2005, 11:27 PM
Blasted rules. Someone should start a FIRST without rules. Except maybe weight, size, and build season limits. But other than that you are free to destroy, reprogram wirelessly, or otherwise do fun stuff. I think im getting tired again. Id better shut up.