/*
     SerialSARAPassthrough sketch

     This sketch allows you to send AT commands from the USB CDC serial port
     of the MKR NB 1500 board to the onboard ublox SARA-R410 celluar module.

     For a list of supported AT commands see:
     https://www.u-blox.com/sites/default/files/u-blox-CEL_ATCommands_%28UBX-13002752%29.pdf

     Circuit:
     - MKR NB 1500 board
     - Antenna
     - 1500 mAh or higher lipo battery connected
     - SIM card

     Make sure the Serial Monitor's line ending is set to "Both NL and CR"
     create 11 December 2017
     Sandeep Mistry
  */

  // baud rate used for both Serial ports
  unsigned long baud = 115200;

  void setup() {
    // enable the POW_ON pin
    pinMode(SARA_PWR_ON, OUTPUT);
    digitalWrite(SARA_PWR_ON, HIGH);

    // reset the ublox module
    pinMode(SARA_RESETN, OUTPUT);
    digitalWrite(SARA_RESETN, HIGH);
    delay(100);
    digitalWrite(SARA_RESETN, LOW);

    Serial.begin(baud);
    SerialSARA.begin(baud);
  }

  void loop() {
    if (Serial.available()) {
      SerialSARA.write(Serial.read());
    }

    if (SerialSARA.available()) {
     Serial.write(SerialSARA.read());
   }
 }