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sam: Missing support for HardwareSerial configuration #2966

Closed udoklein closed 9 years ago

udoklein commented 9 years ago

With commit https://github.com/arduino/Arduino/commit/1fab8c85e6d1b545ef88cb99965e0234bf3c2f8b on Jan 16 2014 the AVR version of HardwareSerial introduced a new method void HardwareSerial::begin(unsigned long baud, byte config) The SAM version https://github.com/arduino/Arduino/blob/master/hardware/arduino/sam/cores/arduino/HardwareSerial.h does not offer this kind of feature. According to the documentation http://arduino.cc/en/Serial/Begin I would have assumed that the SAM version offers this as well. How can this be fixed? Reason why I would need it: in my DCF77 project I have a "Meinberg Emulator" http://blog.blinkenlight.net/experiments/dcf77/meinberg-emulator/. This Emulator requires serial communication with mode 7e2. I want to port this to support both AVR and SAM.

cmaglie commented 9 years ago

Unfortunately, the 2-stop-bits modes are available only on the alternative serial ports of the Due (Serial1, Serial2, Serial3) but not on first one (Serial).

The reason is that pins from 14 to 19 (Serial1/2/3) have been mapped to SAM3X's USARTs that supports all the serial modes, instead pins 0/1 (Serial) on UART that support only a few modes.

Here the reference code: https://github.com/arduino/Arduino/blob/master/hardware/arduino/sam/cores/arduino/UARTClass.h#L28 https://github.com/arduino/Arduino/blob/master/hardware/arduino/sam/cores/arduino/USARTClass.h#L28

udoklein commented 9 years ago

Aha, got it. This implies that I can have 7e2 if I am willing to connect to pins other than 0, 1. Or i have to use the native USB port to emulate a serial port. Thanks for pointing me in the right direction.