Alternate firmware for genMDM devices to work as a Port 2 Serial cable for rhargreaves/mega-drive-midi-interface

genmdm-alt.ino

#include <SoftwareSerial.h>
SoftwareSerial softSerial(11, 2);

void setup()
{
  Serial.begin(115200);

  while (!Serial) {
    ; // wait for serial port to connect. Needed for Native USB only
  }
  
  softSerial.begin(4800);
}

void loop()
{
  if (Serial.available()) {      // If anything comes in Serial (USB),
    softSerial.write(Serial.read());   // read it and send it out softSerial (pins 11 & 2)
  }

  if (softSerial.available()) {     // If anything comes in softSerial (pins 11 & 2)
    Serial.write(softSerial.read());   // read it and send it out Serial (USB)
  }
}