[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