Intermittent connection on field only
 

We're competing at the LA regional this weekend, and are having nothing but trouble when competing on the field. We lose communication at completely random times (moving, not moving, before match, during match, etc), and for random durations (for anywhere between a few seconds to almost the entire match). However, this only occurs when we are on the competition field with FMS, but has happened in every single match. When we run tethered in the pit, tethered on the practice field, and wireless on the practice field (with the practice field radio), it works perfectly, no hiccups.

We've replaced the following components, with no effect: cRIO, radio, ethernet cable, driver station computer, and radio 12-5v power converter. It occurs with the default LabVIEW code as well as our own code. We pulled every single circuit breaker, so that the only items powered were the cRIO and the radio, and it still occurred. We've had multiple people from our team, other teams, and event staff check our wiring, and wiggle the wires looking for shorts or loose connections, but haven't found anything. Our chassis is open to ground. cRIO is mounted to wood, and the camera is mounted to plastic. Our radio is mounted pretty high, and not overly surrounded by metal. The closest motor is around 12 inches away. We are not using any of the banebots 775 motors.

About the only control system component that we haven't replaced is PD board. I've used a DMM to look at the 24v and 12v power supplies, and both seemed fine. 24v supply was at 23.9v and 12v was at the battery voltage (12.5). I didn't see any change when communications dropped. While everything seems good with the PD board, since it's the only thing we haven't changed, I'm worried it's our only choice tomorrow. The PD board is brand new from the kit this year.

Any ideas or additional troubleshooting steps?

Re: Intermittent connection on field only
 

Joe,
sorry to hear of your issues as I can only imagine the frustrations.
I didnt get to watch you folks today, but members of our team clearly saw what was happening to both you and 1717 today.

The only hiccups our team had during the end part of build season was our laptop/driver station blanking out or blue screening at times. Randy found the issue to be with our bluetooth mouse interfering when we ran Labview. We bought brand new i7 core laptops this season due to the kinect.

I hope you find the culprit.
You are usually the source for finding solutions vs. vice versa.

Re: Intermittent connection on field only
 

A few more data points.

This does happen while setting up prior to a match also, while the robot is disabled. We set the robot out on the field, it links up, and then it will randomly lose connection while other robots are being set up.

We are using the camera connected directly to radio. All the code to access the camera on the robot is disabled.

We have customized the dashboard, and our using our own laptop. However the issue occurs on two different laptops. Driver Station CPU utilization is low. We are not using the kinect or the cypress board. cRIO CPU utilization is around 50%, but this happens with the default LabVIEW code also.

We've had two CSA's, the Field Supervisor, and the FTA all look at both the robot and the field logs, without any obvious answers, the robot just loses communication.

There is no correlation with battery voltage as seen in the FMS logs or the DS charts tab. (unless something is happening too fast to see). It happens with multiple batteries.

Re: Intermittent connection on field only
 

In addition to wiggling the wires, have you tightened down the connections (particularly on the PD board)? That bit us one year through an entire regional; one of the wires from the battery to the board was not tightened down really hard. If we wiggled the wire it seemed good, but it wasn't until we tried replacing the wires that we found they weren't tightened properly.

Re: Intermittent connection on field only
 

It looks like this problem happens to the best of em.
We had this same problem in Breakaway, we would lose connection randomly and for a random period of time.

I wish I knew the solution, have you considered changing both CRio and Driver Station computer?
Edit: Nevermind, i see that you have.

Re: Intermittent connection on field only
 

It seems that 364 is having similar issues at the Bayou regional. In that thread, Greg asked for cRIO and radio info. Adding it here for completeness.

We've tried 3 radios, all rev A. Two with firmware version 1.21 (one was ours and one from spare parts) and one with firmware version 1.4 (purchased last month). We've tried 2 cRios, both have been 4 slot cRios (no room for 8 slot).

Re: Intermittent connection on field only
 

If you unplug the camera from the Wireless Gaming adapter, does the problem go away? Can the FTA tell if your robot is more bandwidth hungry than the others at the event?

We had a situation with the symptoms you describe happen at the Chestnut Hill District Event, and the FTA ultimately traced the problem down to a pair of particularly bandwidth hungry robots. After they changed their camera settings (lowered resolution, lowered framerate, increased compression), I believe the problems went away.

I know that there is no worse feeling in FRC than watching your robot die in the middle of the field with no discernible cause.

Re: Intermittent connection on field only
 

3193 was having very similar issues to what you were describing in Pittsburgh. For some reason, the staff was reluctant to let them program a new radio at the kiosk - they brought a brand new one with them from home (not sure of the firmware/rev level on that). Ultimately, the staff relented - they programmed the new radio at the kiosk and then had no issues with on-field robot comms the rest of the competition. The team was also making other repairs to the bot inside the base at the time that might have affected wiring connections, etc., so this might have been a coincidence.

It sounds like you've swapped radios many times already, though.

Re: Intermittent connection on field only
 

We're still at a loss. We're going back to the classmate, eliminating CAN, eliminating the camera. That's the last of the niceties of our robot. We're back to basic framework.

Re: Intermittent connection on field only
 

At Alamo during week 1, the Robonauts had similar problems in a couple matches on Friday. In one match we never started autonomous, and in another we lost connection with 30 seconds remaining.

Changing out the classmate stopped the symptoms. Although I'm not fully convinced the classmate was the root cause, we didn't have any problems afterward. Prior to changing it out, we were seeing delays off the chart (> 100 msec) and approaching 50 lost packets per unit time, even when tethered. This went away after we swapped the classmate.

Re: Intermittent connection on field only
 

No go still. This is sickening. We're at the point where the only variable left is the FMS, and they're not budging. It's not code, it's not electrical, it's not us.

We also moved the router to an unpopulated part of the robot because of interference worries. I don't know what's left.

Frankly, I'm pissed off because of this. FTA has given little support so far.

Our problem still occurred even with the camera unplugged and unpowered. At one point we pulled all breakers so only the radio and crio had power.

This morning, we swapped the PD board and it ran perfectly in our first match. 2 more qualification matches to go.

Sent from my BlackBerry 9650 using Tapatalk

Re: Intermittent connection on field only
 

Murphy says it's always the part that can't be causing the problem, that is the problem....

Hope it stays fixed!

Re: Intermittent connection on field only
 

Joe,
The 12 volt output for the radio should be 12 volts +/- 0.1 volts. It should not read the same as the battery. Since you replace the PD already, I am going to guess that the 12 volt supply has a problem. However, none of this explains the action on the field vs all other trials. If the radio resets due to a power dump it takes about 50 seconds. The new FMS dashboard also reports lost packets. Were you told that there were cluster of lost packets on your data stream? They also have the ability to check emissions on your channel, have they looked at that? Normally they only check prior to the event and not during the event. It really sounds like something is interfering with your radio. I know it's not supposed to happen but it obviously is. What is the possibility that your WPA key is corrupt in the kiosk? Have you always configured at the same kiosk or did you try the second one?

Re: Intermittent connection on field only
 

My understanding is that it tracks battery voltage at >12 volts. That may be wrong.