CP Express Hardware Serial in Arduino IDE

[crcibernetica]

Using CP Classic I access the USB serial port using "Serial" and the RX/TX serial using "Serial1".
The same naming does not work for me using a CP Express. What is the correct way to access the hardware serial port using the Arduino IDE?

Regards,

Ubuntu 16.04LTS
Arduino IDE 1.8.5

[danhalbert]

What errors are you seeing?

https://learn.adafruit.com/adafruit-cir ... -serialusb discusses one issue. As described there, you need to make sure to install both the Arduino and Adafruit SAMD M0 board packages to get `Serial` instead of `SerialUSB`.

If you want to use the non-USB Serial1, it appears on the pads labeled "RX" and "TX" (A6 and A7). I ran the simple program below (also on Ubuntu, as you did) and saw appropriate output on the TX pin with my logic analyzer:

Code: Select all

void setup() {
  Serial1.begin(9600);
}

void loop() {
  Serial1.write('a');
}

[crcibernetica]

I think CircuitPlayground.begin() sets up the capacitive touch pins and overwrites any Serial1 port that has been previously initialized. Using Serial.begin(9600) and Serial1.begin(9600) after CircuitPlayground.begin() seems to work.