Cannot send packet inside notify* functions about loconet2 HOT 2 CLOSED

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Hi Alex. Thanks for the response.

Actually what I was pointing out is not the inherent issue with LocoNet protocol but the way it is implemented. The problem lies in that the task that sends bits to network also does receiving and processing bits from network. So when a packet arrives, its notify function is called from that task. If there is a send inside notify function, the task comes to a busy loop that waits for data to be sent. But that is never sent because sending is done by that same task. If, for example, sending was implemented in another task or by timer interrupt (as it is done in AVR version), there would be no issue even considering CD backoffs and stuff - sending would eventually succeed and the task would continue.

I found only one fork that had some commits. The timer+bitbanging code does not seem to work (or I've messed with its timings somehow), but there is an implementation via UART driver that kinda works but does not allow to invert tx pin while not inverting rx pin - which most DIY LocoNet schematics require. On the good side, it does not seem to be deadlocking in the described case, though I have not tested it yet.

Anyway, thanks for your good work with the libraries. I'll keep poking around in the library and its fork, trying to fit it to my hardware and software requirements, probably making some changes in the process. Do you accept pull requests though?

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