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neilh10 / ModularSensors

A forked ModularSensors for a rugged solar powered logger; Mayfly.
https://github.com/neilh10/ModularSensors/wiki
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SDI-12/Wio Terminal #72

Open neilh10 opened 3 years ago

neilh10 commented 3 years ago

Add Wio Terminal to the Arduino-SDI12 library

neilh10 commented 3 years ago

Arduino-SDI-12 sw implementation requires a bit clock that is accurately timed at 1200*13bits or 15,600Hz The Wio Terminal uses ATSAMD51P19 which has a complex set of clocks. CycleCounter - runs at 120MHz can be read directly, and arithmetically divided down to the bit clock.

Alternatives: GCK5 - 1 Mhz that can be routed to a counter like TC_3 with a divisor of 64 for a 15,625Hz counter Part of the TC (Time Counter) features is they haver pre-scaler as a power of 2 from 1~1024 The "GCK"s can have a divider that is any number. So an alternative is to create a new GCK (GCK6), feed from the 48MHz, divide by 3 to have an output of 16MHz, and then for the TC pre-scaler to use 1024.