I ordered XRP Beta hardware (https://www.sparkfun.com/products/22230, part #22230) on 28Apr2023, and received it on 27Aug2023, and have assembled it.
When I try running code that should drive [both of] the motors, only one responds (i.e., only one wheel turns). This is 100% reproducible with simple code using the Blockley interface in the XRP Code Editor, and with the XRP Reference program (available after installing the current WPILib Alpha build for the 2024 FRC season, and after reprogramming the XRP with the WPILib firmware (https://github.com/wpilibsuite/xrp-wpilib-firmware)).
I initially thought that this might be indicating that one of the cables was incorrectly seated, or that there was a problem with one of the ports on the controller board. However, when I swap the left and right motors (i.e., move the motor plugged into Motor R over to the Motor L port, etc.), the motor that worked when plugged into one side still works when plugged into the other, while the failing motor still fails. I have also tried reseating the cables connecting the board to the motors (with no net change), and swapping the motors from one cable to another (with the failure continuing to follow the motor).
These results tend to suggest that the problem is not a software issue, a problem with the port, or a problem with the cable, but rather a failing motor.
I reached out to SparkFun customer support to report the issue, and was directed to post a request for support here, along with a video demonstrating the issue (https://photos.app.goo.gl/8XWVmjmvyNk1FN898 was recorded using the aforementioned “XRP Reference” sample Java code, running on a MacBook Pro under the 2024 Alpha 1 version of the WPILib tools.
Per the directions provided, I’ve uploaded a video of the XRP demonstrating this problem (https://photos.google.com/photo/AF1QipN … _EvPQciPDc), where:
As can be seen in the video, only the wheel on one side of the robot is turning. (If needed, I’ll be happy to upload a second video with the motors swapped, subsequently showing that only the wheel on the other side of the robot is turning.)
As indicated above, I believe that this is a problem with the motor hardware, rather than the RasPi-based controller or the sample code being used.
Please let me know what the next steps should be in resolving this issue: we’re hoping to validate the XRP as a viable training unit for our FRC team, and then order more units once they are available.
Thanks!
-mjh
PS - If needed, I’m also more than happy to provide the order #, etc., but as this is not listed as required information on the “How to get assistance” post, I’m leaving this out for now.