GSMExtras Library

This library complements the Arduino GSM library by providing additional commands for controlling the Quectel M10 GSM module found on the Arduino GSM shield, DIY Cellphone, and Cellphone Module.

GSM3VolumeService

To use: #include <GSM3VolumeService.h>

void setVolume(int);

Set the volume, from 0 to 100.

void checkVolume();

Query the GSM module for the current volume. Use ready() to check if the module has responded and getVolume() to retrieve the current volume.

volume.checkVolume(); // query the GSM module for the current volume
while (!volume.ready()); // wait for it to respond

// if the response was successful, get the volume and print it
if (volume.ready() == 1) {
  Serial.print("volume: ");
  Serial.println(volume.getVolume());
}

int getVolume();

Returns the current volume, either the last volume set with setVolume() or the last volume returned by the module through a call to checkVolume().

int ready();

Check the status of the latest query of the GSM module (with checkVolume()). Returns 0 if the command is still pending, 1 on success, and greater than 1 on error.

Example Code

#include <GSM.h>
#include <GSM3VolumeService.h>

GSM gsm(true);
GSMVoiceCall vcs;
GSM3VolumeService volume;
int potval;

void setup()
{
  pinMode(31, INPUT_PULLUP);
  pinMode(19, OUTPUT);
  digitalWrite(19, LOW);
  delay(12000);
  digitalWrite(19, HIGH);  
  while (gsm.begin(0, false) != GSM_READY);
}

void loop()
{
  if (vcs.getvoiceCallStatus() == RECEIVINGCALL && digitalRead(31) == LOW) { vcs.answerCall(); delay(500); }
  if (vcs.getvoiceCallStatus() == TALKING && digitalRead(31) == LOW) { vcs.hangCall(); delay(500); }
  
  // if the reading from the analog input has changed by some small amount, set the volume
  if (abs(analogRead(A0) - potval) > 10) {
    // analogRead() returns values from 0 to 1023, map that to 0 to 100 (the range for setVolume).
    potval = analogRead(A0);
    volume.setVolume(map(potval, 0, 1023, 0, 100));
  }
}