Description
I've got a MatrixPortal board running CircuitPython which is having some issues. If I connect the board to a PC (or any device that can handle the MatrixPortal's USB serial output), then the board runs fine for extended periods of time. If I hook it up to a charger (or a PC that is sleeping, etc), then the board will eventually hang.
I've run a few experiments and been able to demonstrate that I can get the board out of the hung state by waking the PC it is connected to.
Here's a simple sample to reproduce:
import time
count = 0
while True:
print(count)
for i in range(2000):
print(count, end=" ")
print("\nnaptime")
time.sleep(300)
- Plug MatrixPortal into a PC
- Upload the code snippet above
- Monitor the serial output and confirm that the code is working properly
- Put the PC to sleep
- Wait some length of time (hours produces the most obvious result)
- Wake the PC and check the serial output
The expected result is that the "count" value printed should be approximately "the amount of time the board has been active, divided by five minutes." In my experiments, the "count" value printed was much lower.
The amount of loops that the board is capable of doing before it hangs can be changed by changing the amount of printing that is done on each loop. (ie, change the constant in the range(2000) call). This would seem to indicate that the issue is that the print statement is hanging, possibly due to a buffer being full? I'm not that familiar with the lower level CircuitPython (or MatrixPortal support).