I've been forced to use bootloader mode to reprogram my microcontrollers and regain access to the ports Arduino IDE (Feather M0, Razor IMU).

When I try to upload the example code, it is successful but the port always disappears, removing the ability to check serial monitor or upload new code.

Main problem: sensor breakout code uploads "successfully" to an RFDuino, but has no outputs on serial monitor (not even Serial.println("foo") after Serial.begin), making debugging/data collection difficult.

I am using a Simblee RFD77201 with a SparkFun MS5803 14-bar pressure sensor. The code is (very slightly) modified from this breakout code (changed CELSIUS and FAHRENHEIT to CELSIUS1 and FAHRENHEIT1 in libraries and sketch because were already defined in RFD library), and is attached (libraries are MS5803_14.cpp and .h, modified sketch is PLEASEWORKPLEASE.ino). The RFD does recognize the sensor at the correct address (0x76) when running an I2C device scanner (sketch attached as I2C_scanner.ino). The sensor is connected to the RFD as follows: SDA to GPIO6, SCL to GPIO5, GND to GND, +3V to +3V (using the USB shield so it's receiving 3.3V as it should).

Thank you!

files_RFDcompatibilityIssue.zip

Observed on the Thing Dev. The ESP8266 has the same issue as #1

The same solution works as well. That is:

(1) Go to the .cpp file (here, Sparkfun_MS5803_I2C.cpp) and comment out Wire.begin() (here, in the MS5803::MS5803(ms5803_addr address) function)

(2) In the sketch, insert Wire.begin() after the Serial.begin() line. It won't work before it.