MicroPython Forum (Archive)

During a normal boot, the green LED is turned on here: https://github.com/micropython/micropython/blob/master/stmhal/main.c#L317 and turned off here: https://github.com/micropython/micropython/blob/master/stmhal/main.c#L470 So that adds virtually no delay. I think you'd need to profile the boot to s...

The next thing is to make sure that the firmware was configured with the crystal frequency you're actually using. The pyboard uses an 8Mhz crystal. I did a port to the Cerb40 II, which is basically just a 405 on a DIP carrier. If you look at stmhal/boards/CERB40 you can see the files which were crea...

Thanks- that helps a lot. Looks like I missed several things, especially the tricky little circuit on the bottom of P19. It appears you have to pull USB-DP up to 3.3V, although I don't see where that happens on the Pyboard.... Still don't have it working, but I have a bunch of things to try. Those ...

You didn't mention BOOT1. I believe it has to be low and BOOT0 has to be high (at RESET time) to enter DFU mode. There are a bunch of other pins which need to have pullups/pulldowns on them. See this document: http://www.st.com/web/en/resource/technical/document/application_note/CD00167594.pdf Page ...

The only caution I have is that sometimes the pyboard will decide to erase it's flash memory (I've had this happen - typically when I'm messing around with interrupts and such). If that happens, then you'll lose all of the your changes since the last commit. I use git repositories as well, but I ten...

Perhaps to help demystify the GC (garbage collector) a bit. When python needs to allocate memory, it goes to the heap, and tries to allocate it. If the allocation succeeds, then life is good and your program continues. If, however, the allocation fails, then the GC is run. The GC figures out which c...

I'm thinking so.

Now that you've confirmed that resetting the counter to zero fixes the problem, I've created a pull request to fix freq and period so that they reset the counter to zero.

I think I would reorder this slightly and make it:

I have a guess as to what's happening. The way that the timers work is that they have a counter and a limit (reload register). When the counter reaches the limit (i.e. is equal to) then it gets reinitialized to zero and continues to count. If the current counter value is larger than the limit regist...

Sweet.