Radio cuts out, student's foot run over

[grantf]

The following is our compliance with the IFI radio recommendations.

You need to be running Master Code 13 when using the new 2007 Radios and a 2006 or 2007 OI.

We were running the v14 Master code when the robot took off.
We are using the 2007 OI and RC only.

As for intermittent stalls; make sure all power connections are tight, from the battery, through the circuit breaker panel and to all devices. Pull on all your power connections. Repair any that are loose or come free. It is best to solder all wire connections; a crimp connection can come free.

We are using quick connects (spade connectors) for all 20 amp lines.
These connectors are from this year's kit and fit very tightly.
All connections were checked.
A charged backup battery was in use.
A fresh main battery was installed only seconds before the incident.

Intermittent stalls can be from breakers tripping. If you have all green LEDs on the RC unit, you do not have a radio problem. If your motors are drawing too much current, the breakers will trip and the motors will be dead for a few seconds until the auto-resetting breaker has reset.

There were times when we only saw the Valid TX light on the OI go on.
Other times the No Data/Radio light was solid red.

If you see the RC’s Radio Modem LED flashing Red, the RC unit is not receiving radio data. This can be caused from Interference from another source, bad Radio Modem Cables, Radio Modems (OI or RC), or in rare cases the RC or OI unit.

Didn't really see this because we were busy chasing the robot.

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.

1. Check
2. Check
3. Check
4. Check
5. Check, I think... the RC Radio Modem is mounted vertically, about 2 feet off the floor, very near 2 aluminum support colums (1 inch square AL tubing, about 3.5 feet long). However, the RC modem is not "sheilded" in a Faraday-Cage sense... most (90% or more) of the antenna's field of view is unobstructed.
6. Check
7. Check, but we haven't tried another channel yet.

I contacted IFI just the other day and reported this issue (robot taking off while apparently disabled).
They said that in 5000+ systems shipped, they have never once come across this issue.
IFI is waiting for us to reproduce the problem.
It would be great if other teams who are experiencing radio issues could try to produce this problem as well.

Thanks for all the feedback,
Grant

[Matt Krass]

Originally Posted by grantf

I contacted IFI just the other day and reported this issue (robot taking off while apparently disabled).
They said that in 5000+ systems shipped, they have never once come across this issue.
IFI is waiting for us to reproduce the problem.
It would be great if other teams who are experiencing radio issues could try to produce this problem as well.

Thanks for all the feedback,
Grant

Did they really say that? That seems a bit like "You're making it up" to me..

..anyways, would it be possible to test this with older radios/firmwares from last season? Sorry if you already tried that and I missed it, I'm kind of in a rush here.

[Eldarion]

Originally Posted by Matt Krass

Did they really say that? That seems a bit like "You're making it up" to me..

..anyways, would it be possible to test this with older radios/firmwares from last season? Sorry if you already tried that and I missed it, I'm kind of in a rush here.

We are using the 2006 radios on the 2007 RC with FW 13 with no problems.

[whytheheckme]

Originally Posted by Eldarion

We are using the 2006 radios on the 2007 RC with FW 13 with no problems.

Yeah... We have a set of 2006 radios that work beautifully. The 2007 radios crap out all the time. And how do they expect you to mount your radio so it is '6-8"' completely away from metal? Do they want a foot long piece of plywood sticking out from the middle of your bot in a direction away from any other part of the bot that doesn't violate the height limit and in a place where the cord can't get caught in moving parts / get run over by robots climbing up your ramp?

Why do the old 06 radios which are RS-232 have no problem, while these new larger RS-422 radios have all sorts of problems.

Also, they wont let us use the old ones. WHY???

Originally Posted by www.ifirobotics.com/radio_modem.shtml

Note: These radios are new for 2007 and can not be used/interchanged with previous radios/modems.

Jacob

[Eldarion]

Originally Posted by whytheheckme

Why do the old 06 radios which are RS-232 have no problem, while these new larger RS-422 radios have all sorts of problems.

Also, they wont let us use the old ones. WHY???



Jacob

Actually, the '06 radios are also RS-422 (none of these radios were ever RS-232). The reason that IFI is not re-using the old radios is that they cannot get any more, as Electrowave (the suppliers of the radios) cannot get parts to build any more--this was in another thread on CD somewhere (I forget where ).

I am not happy about this either. I have also had critical parts discontinued for a product that I designed--not a good place to be.