arduino-opentherm
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jpraus
Support for SAM D21 based microcontrollers (Arduino Zero)
This pull request adds support for SAM D21 based microcontrollers. It was tested with a Sodaq Sara 412 AFF board, but it should work with an Arduino Zero as well, but I don't have one around. A voltage divider is needed to make incoming communication from the thermostat work. The only change in the code is interrupt code specific for SAM D21.
Thank you! Will merge it into the library. What voltage divider is needed and where?
The issue was that the voltage at MASTER-IN was about 1.2V for a low bit (if I remember correctely) which is not low enough for the SAMD21 processor to be seen as a logical low. I used a voltage divider from that pin to ground, with resistors of equal size to scale it down to half that voltage. But maybe you have a better solution?
The issue was that the voltage at MASTER-IN was about 1.2V for a low bit (if I remember correctely) which is not low enough for the SAMD21 processor to be seen as a logical low. I used a voltage divider from that pin to ground, with resistors of equal size to scale it down to half that voltage. But maybe you have a better solution?
I believe this https://github.com/jpraus/arduino-opentherm/issues/20#issuecomment-925286258 fixes this also
