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Unread 25-02-2013, 16:11
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Re: Robot running spikes on reboot?

Quote:
Originally Posted by Iaquinto.Joe View Post
Update: It looks like the robot was setting relay values from the last recieved teleop packet. Adding code to disable all actuators in DisabledInit solved the issue.
The only problem here is that the relay outputs and PWM outputs are supposed to be electrically buffered in the Digital Sidecar. There's a /Output_En signal that needs to be pulled low to enable any of the outputs. The cRIO image is supposed to be set up to only pull that pin low in Teleop Enabled or Autonomous Enabled. That pin shouldn't be pulled low during a reboot. So there's only a few possibilities:
1. There's a problem with the cRIO image that makes this happen. In which case there should be lots more reports of it happening.
2. You have some electrical problem that's shorting this pin/trace to ground. This could be a bad sidecar, a nicked ribbon cable, a bad NI module, a metal shaving in exactly the wrong place... A whole lot of things, but something unique to your robot.

I think it's really important to try to determine the root cause of this and not just patch around one of the symptoms. If the problem is actually #1, then FIRST needs to know so the cRIO image can be fixed to work safely. If the problem is #2, then you need to solve the actual problem, because this means your robot is capable of running relays, and perhaps motors, in Disabled mode. That's all kinds of illegal and unsafe. So please do try to figure out where the actual problem is. If it's still happening despite swapping sidecars, I'm guessing the problem is in your ribbon cable or NI module.
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