Quote:
Originally Posted by Trevor4004
My team recently received our navX board and we are very excited about the possibilities it will give us. However, the power LED on the RoboRio turns a solid red when we plug it directly into the MXP area of the RoboRio as described in the Plug-n-Play section of the navx-mxp wiki ( https://code.google.com/p/navx-mxp/wiki/RoboRioInstall). The RoboRio User Manual says that a solid red for the power LED means "Fault condition detected. One or more user voltage rails are in short-circuit or overcurrent condition."
Our first thought was that the short-circuit or overcurrent problems were due to some strange interaction between the naxv board connecting to the RoboRio via MXP and our daisy chain going from the RoboRio to the PDP and containing 4 talon srxs and the PCM. But this doesn't seem to make a lot of sense considering this board is supposed to be designed to work with the RoboRio for FRC and a daisy chain of 4 talons and the PCM seems like a common setup in FRC.
We can still connect to the robot with out driver station, and we get full communication and robot code when we do. We are able to drive the robot around normally, but we are worried about trying to test the navx in our code until we can determine why the RoboRio is detecting a short-circuit or overcurrent condition. Any insight into why the RoboRio is detecting these problems would be greatly appreciated. Thank you. |
This sounds like a short between one of the power (or potentially signal, if active) pins and one of the ground pins on the navX MXP's MXP Expansion connectors. This could be any of the DigitalI/O\PWM\QuadEncoder, Analog In, Analog Out, I2C, SPI or TTL UART connectors. In this case, the navX MXP's RED Power LEDs, and green S1/S2 LEDs will be all off - the navX MXP isn't getting any power from the RoboRIO in this case, because the RoboRIO is protecting itself from a short. The RoboRIO appears well-designed to deal w/this case.
Note that the RoboRIO can be powered via USB, in which case the navX MXP's sensors and microcontroller will work, even if there's a short on the MXP Expansion voltage rail. But in this case, the voltage on the navX MXP expansion connectors will be unavailable, so you won't be able to communicate w/the RoboRIO from the navX MXP via the TTL UART / I2C or SPI interfaces - and you won't be able to use the navX MXP expansion connectors. You'll be limited to using USB unless the source of the short is found and corrected.
So work on finding any shorts, I believe this is the source of the issue you are seeing.