make UART.write be blocking on SAMD; add timeout property #2331
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tannewt
requested changes
Nov 27, 2019
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UARTfixes and changes:UART.write()was inadvertently non-blocking, due to my misunderstanding the (poorly documented) ASF4 API. Fixes busio.UART write sometimes returns None #2263, I believe.timeoutapply only to read. Note, for instance, that PySerial has separate read, write, and inter-character timeouts..timeoutproperty so that the timeout can be changed after construction.board.UART(). It was 1000.0 seconds, should have been 1 second (leftover from msecs to msecs API change previously).Tested on atmel-samd, nrf, and stm32f4. Not tested on spresense because I don't have one yet.
I tried making
UART.writeinterruptible by ctrl-C on atmel-samd, but it causes the ASF4 driver to get irreversibly confused about whether it's completed the write or not, and there's no easy API call to reset it. It's not possible to have ctrl-C interrupts on some other ports anyway, so never mind.@jepler if you want to review, feel free, but no obligation. Not sure how we should divvy up reviewing in the future.