Posted at 2014-07-09 by user7143

Interesting post. I receive a FONA GSM board from Adafruit tomorrow. So I have been trying to figure out the same thing. I have been studying the npm modem code to try and understand the way to handle callbacks from a AT modem.

Posted at 2014-07-09 by @gfwilliams

Hi,

About the console.log - it won't hurt to use it when running off a battery - you just won't see anything. I guess you could define a function like:

function log(type, message) {
  if (type=="good") digitalWrite(LED2,1); // green
  if (type=="bad") digitalWrite(LED1,1); // red
  console.log(">"+message);
}

log("good", "It worked!");
log("", "It's ok...");
log("bad", "It's smoking");

You could also try calling a callback for the response message, rather than using intervals...

I've added a timeout so it won't just break if something goes wrong, but I'm not handling it very well at the moment :)

var cmd="";
var responseText = "OK";
var responseCallback = undefined;
 
//Function handles data coming in from Serial.
Serial4.on('data',function (data) {
  cmd+=data;
  // maybe we should be looking for newline instead?
  if(cmd.indexOf(responseText) > 0){
    console.log(cmd);
    if (responseCallback) responseCallback();
    responseCallback = undefined;
    cmd="";
  }
});
 
 
//Function handles sending AT commands to GSM device.
function Send_Command(command,response,time,caller){
  if (responseCallback) {
    console.log("we were already doing something!");
    return;
  }
  
  // if we didn't get anything within 'time' ms, 
  var timeout = setTimeout(function(){    
    console.log("Timeout for "+command);
    caller(false);
  },time);
  responseText = response;
  responseCallback = function() {
   // if we actually did want to repeatedly send the command, do it here
   clearInterval(timeout); // clear the timeout
   caller(true);
  };
  // send command
  Serial4.write(command);
}
 
 
//Start the GSM Module
function Start_GSM(callback) {
  console.log("GSM Starting...");
  pinMode(C0,"output");
  digitalPulse(C0,1,2000);
  // this will send the AT command right after C0 has raised.
  // Not sure it's what you want? setTimeout might be better here
  Send_Command("AT\r\n","OK",500,function() {
    console.log("GSM Started.");
    callback();
  });
}

//Send the text message
function Send_SMS(phoneNumber,message, callback){
 console.log("Setting SMS Mode..");
  Send_Command("AT+CMGF=1\r\n","OK",1000,function(){
    answer=">";
    console.log("Setting Phone Number.."); 
    Send_Command('AT+CMGS=\""+phoneNumber+"\"\r',">",1000,function(){
      console.log("Send Message"); 
      Send_Command(message+"\x1A\r","OK",3000,function() {
       console.log("Message Sent"); 
       callback();
      });
    });
  });
}

// You can then chain the callbacks together to use the library
Start_GSM(function() {
  Send_SMS("+441234567890","Hello There", function() {
     Send_SMS("+441234567890","Hello There Again", function() {
      Stop_GSM(function() {
         console.log("phew...");
      });
     });
   });
});

Posted at 2014-07-10 by Hardware_Hacks

Thanks for the example I've given it a try and got a bit muddled up will review properly tonight though. I see the serial4.setup is missing which might be the issue.

Posted at 2014-07-10 by @gfwilliams

Ahh - yes. I don't have GSM here to test it with though...

Posted at 2014-07-10 by Hardware_Hacks

No problem I understand the principles anyway

Posted at 2014-07-10 by user7143

I am also trying same test. As well as serial setup I see a few other things that I dont quite understand. Does espruino have a blocking timeout command? when setting c0 high for 2 seconds using digitalPulse does not block I tried using setTimeout(function(){},2000); after digitalPulse, the code continues and sends AT commands before the GSM unit turns on.

I am struggling to understand how the responseCallback routine works.

I am finding it really interesting to read and try to debug code. It gives a much better understanding of the way that Javascript works.

Posted at 2014-07-10 by Hardware_Hacks

I'm unsure on how the flora GSM board works @user7143 as the c0 high for 2 seconds is specific to the GSM2 click board I am using. It tells the board to turn on/off. This may not need to be the case in your instance (unsure but worth checking).

Posted at 2014-07-10 by user7143

Fona also requires 2 second high pulse to turn on/off board. I have might not explained correctly but when I run Gordon's code the digitalPulse command does not seem to block. Hence the other AT commands to initialize the board are sent before the GSM board is powered on.

Thinking about his maybe the Send_Command in the start_GSM function needs to be fired from a SetTimeout command that waits for 2 seconds to allow for the GSM board to be powered on. That way the commands are sent and read rather than being lost.

I think most GSM boards are going to have the same command set so once the code is working it will be relevant to a number of GSM boards.

Posted at 2014-07-10 by @gfwilliams

Yes, I had a feeling that digitalPulse(C0,1,2000); may not have been quite right.

The best thing is probably just to replace it altogether:

digitalWrite(C0,1);
setTimeout(function() {
  digitalWrite(C0,0);
  Send_Command(...)
}, 2000);

Of course you might need to wait a few ms after taking C0 low again too...

Posted at 2014-07-10 by Hardware_Hacks

Looks to be quite a bit not working I think im going to go back to basics on this one and give it another shot!

Posted at 2014-07-10 by user7143

Serial4.println() allows the modem to be set up. The Serial.write does not seem to work

Posted at 2014-07-11 by Hardware_Hacks

Odd.. Write has been perfect for me. I have some working code now but doesn't really look much like the stuff above. I'm trying to decide how best to receive the send command output and check its content still.

Posted at 2014-07-11 by @gfwilliams

@user7143 Serial.write won't send a newline automatically, so you'll have to send it explicitly with \n or \r. Could that be your problem?

Posted at 2014-07-11 by user7143

Took another look at the Serial.write cmd. I had the / \ mixed up. Now it seems to work.

On to the issue of reading and processing the send command output. Would a swicth statement in the serial.on("data") make sense?

if I send the command Serial.write("AT+CBC\n\r", 500, "+CBC",function(){}); to check the battery voltage I get +cbc: 0,94,3978 returned from the serial port. With a switch statement I could act on this by parsing the +cbc from the line and comparing it to the expected response from the Serial.write line (+CBC). If these agree I could then return an array for the 0,94,3878, that shows battery % charge left and the battery voltage.

I will try to code this later today if someone agrees this is a good way to proceed.

Posted at 2014-07-11 by Hardware_Hacks

@user7143 yeap thats the route you should go down in my opinion.

Typically you will take the response from the on.data, build up a buffer to get a complete command and then check the command to see if it has the required response.

I was part the way implementing that and got confused over how I wanted to go about it. You will see in my original code I had an answer variable which stored the expected response agains the sent command. Note. The answer is not always OK nor is it always the expected answer.

I was hoping to do the check agains the response buffer to see if I got what I wanted in return. If I didnt I would just raise and error and shutdown the module.

There is also the scenario where you have slow response or no initial response. This is why I had the timer implemented into the send command function. This meant that I could repeatedly run the command every few seconds if I didnt get an answer back from the module. There is also the scenario where the command times out, so how long do you want to keep sending a command or waiting for a response until you decide the module is either dead or unresponsive? You can potentially end up in a loop.

As you can see there are a few things to consider and I think I rushed in to it at first without splitting all of the problems down and building out the solution. In my confusion I created quite a mess which I'm now working on to fix. Would be good if you could share your code though might help me get a bit further on my work :)

Posted at 2014-07-11 by user7143

Will work on the Switch code and share when I have a few minutes free. This should take care of the differing responses based on different commands. A if statement before the switch statement should be able to check the expected response vs actual response.

The Digital.write code that Gordon posted above still does not seem to work correctly. I think rather than using a delay time after the 2 second high turn on code is run, the right way to handle this is to read a pin on the modem that lights up the ready LED to make sure the modem is ready to read commands.

This is fun stuff!

Posted at 2014-07-11 by Hardware_Hacks

This is where I'm at after a refresh.

var cmd="";

//Function handles data coming in from Serial.
Serial4.on('data',function (c) {

  if(c==="\r")
  {  
    parseResponse(cmd);
    cmd="";
  }
   cmd+=c;
});


//Parse responses on data received on serial
function parseResponse(buffer){
   if(buffer.length < 2)
     return; 

     if(buffer.indexOf("ERROR:")>0){
     console.log("Error - forcing shutdown");
      Stop_GSM();   
      }
    else
     {
       console.log(buffer);
     }
}



function Send_SMS(text)
{
  Start_GSM();
  setTimeout(function(){send(text);},10000);
}


//Start the GSM Module
function Start_GSM() {
  Serial4.setup(9600);
  console.log("GSM Starting...");
  pinMode(C0,"output");
  digitalPulse(C0,1,2000);
}

function Stop_GSM(){
pinMode(C0,"output");
digitalPulse(C0,1,2000);
}



function send(input){
    setTimeout(function(){send_command("AT+CMGS=\"number here\"\r");},2000);
    setTimeout(function(){send_command(input+"\x1A\r");},3000);
  setTimeout(function(){Stop_GSM();},10000);
}



function send_command(command){
//Send the command to serial port connected to GSM
  Serial4.write(command);
}



function onInit(){
Send_SMS("Heyyyy!");
}

onInit();

For me the timed sending of commands is enough to get things running and sending texts. I just need to add in my GPS code and I'll have a tracker that can sms coords to twilio. My JS skills arent up to doing anything better.

Posted at 2014-07-12 by Hardware_Hacks

Things working a bit nicer now!

var cmd="";
var issued_command="";




//Parse response v2
function parse(buffer){
  var line = buffer.toString().substring(0, buffer.length - 1);


  //Remove anything remotely blank or echoey
  if(line.length < 2 || line.indexOf(">")===0 || issued_command===line){
     return;
  }

  issued_command="";

  //SMS Received
  if(line.indexOf("+CMTI")>0){
     console.log("SMS Received");
     }
  
  //Response Received
  console.log("Parsed: " + line);
}



//Serial on data v2
Serial4.on('data',function(data){
cmd += data;
  var id = cmd.indexOf("\n");
  while (id>=0){
  var line = cmd.substr(0,id);
  cmd=cmd.substr(id+1);
  parse(line);
  id=cmd.indexOf("\n");
  }
});




function Send_SMS(text)
{
  Start_GSM();
  setTimeout(function(){send(text);},10000);
}


//Start the GSM Module
function Start_GSM() {
  Serial4.setup(9600);
  console.log("GSM Starting...");
  pinMode(C0,"output");
  digitalPulse(C0,1,2000);
}

function Stop_GSM(){
pinMode(C0,"output");
digitalPulse(C0,1,2000);
}



function send(input){
    setTimeout(function(){send_command("AT+CMGS=\"XXXXXXXXXX\"\r");},2000);
    setTimeout(function(){send_command(input);},3000);
  setTimeout(function(){send_command("\x1A\r");},3500);
  setTimeout(function(){Stop_GSM();},10000);
}



function send_command(command){
//Set the command that we are sending to issue_command for later parse out
issued_command=command;
//Send the command to serial port connected to GSM
  Serial4.write(command);
//Output what we sent to console
  console.log("Command Sent:" + command);
}



function onInit(){
Send_SMS("Heyyyy!");
}

onInit();

Results in:

 1v66 Copyright 2014 G.Williams
>echo(0);
GSM Starting...
=undefined
Command Sent:AT+CMGS="xxxxxx94740"
Command Sent:Heyyyy!
Command Sent:�
Parsed: +CMGS: 96
Parsed: OK
Parsed: NORMAL POWER DOWN

Now I guess we can do lots with the Parsed responses and I have added in an example of a SMS received which the console will pick up on.

You can add in some error handling and also wait for an OK from an AT send on startup. I think I'll work on the latter next so that I can then kick off the actual SMS sending via callbacks once I'm sure the module is running.

Posted at 2014-07-14 by user7143

Tried to add some parsing to build on your code.

Also added some functions like get_signal(), get_voltage(), get_network()

saying lights on or lights off in a message line will turn on LEDs on espruino board.

Posted at 2014-07-14 by user7143

var cmd="";
var issued_command="";

Serial4.setup(9600,{rx:C11,tx:C10});

//Parse response v2
function parse(buffer){
  var line = buffer.toString().substring(0, buffer.length - 1);
  //Remove anything remotely blank or echoey
  if(line.length < 2 || line.indexOf(">")===0 || issued_command===line){
     return;
  }
  issued_command="";
  //SMS Received


  if(line.indexOf("+")>-1){
    var d = line.substr(line.indexOf("+")+1,line.indexOf(":")-1); 
       switch(d) {

         case "CMTI":
           tnum = line.split(",");
           console.log("SMS received #", tnum[1]);
           setTimeout(function(){send_command("at+cmgr="+tnum[1]+"\r");},1000);
           break;
          //read incoming SMS

         case "CSQ":
           sgnl = line.slice(5);
           sgnl = sgnl.split(",");
           console.log("signal strength "+sgnl[0]);
           //console.log(line);
           break;
           //Read cell signal

         case "CMGL":
           //console.log("all text messages in memory ");
           break;
           //View all text message in memory

           case "CMGR":
           console.log("text message "+line);
           break;
         //read individual text message in memory
         case "COPS":
           ntwk = line.slice(5);
           ntwk = ntwk.split(",");
           console.log("network "+ ntwk[2]);
           break;
           //Read network carrier

         case "CBC":
           chg = line.split(",");
           console.log("battery charge " + chg[1] + "% + " + chg[2] + "mv's");
           break;
          //read battery charge

    }

     }

   //Turn on LED's if command sent!  
   else if (line.indexOf("Lights on")>-1) {
    console.log("do something");
    LED.write(1);
    LED2.write(1);
  }

    //Turn off LED's if command sent. 
    else if (line.indexOf("lights off")>-1) {
    LED.write(0);
    LED2.write(0); 
  }

     else {
  //Response Received
  console.log("Parsed: " + line);
     }}
  //Serial on data v2
Serial4.on('data',function(data){
cmd += data;
  var id = cmd.indexOf("\n");
  while (id>=0){
  var line = cmd.substr(0,id);
  cmd=cmd.substr(id+1);
  parse(line);
  id=cmd.indexOf("\n");
  }
});
  // get network carier
function get_network() {
  setTimeout(function(){send_command("at+cops?\r");},200);

}
  //get signal strength
function get_signal() {
  setTimeout(function(){send_command("at+csq\r");},200);
  }
  //read all texts in memory
function read_all_text() {
  setTimeout(function(){send_command("at+cmgl=\"all\"\r");},200);

}
  //bet battery % charge and voltage
function get_voltage() {
  setTimeout(function(){send_command("at+cbc\r");},200);

}

function Send_SMS(text)
{
  Start_GSM();
  setTimeout(function(){send(text);},1000);
}
  //Start the GSM Module
function Start_GSM() {

  console.log("GSM Starting...");
  pinMode(C0,"output");
  digitalPulse(C0,1,2000);
  setTimeout(function(){send_command("at+cmgf=1\r");},1000);
}
function Stop_GSM(){
pinMode(C0,"output");
digitalPulse(C0,1,2000);
}
function send(input){
  setTimeout(function(){send_command("AT+CMGS=\"xxxxxxxxxx\"\r");},2000);
  setTimeout(function(){send_command(input);},3000);
  setTimeout(function(){send_command("\x1A\r");},3500);
  setTimeout(function(){Stop_GSM();},10000);
}
function send_command(command){
//Set the command that we are sending to issue_command for later parse out
issued_command=command;
//Send the command to serial port connected to GSM
  Serial4.write(command);
//Output what we sent to console
  console.log("Command Sent:" + command);
}
function onInit(){
  // send SMS when BTN pressed
  setWatch(function(e) { Send_SMS("Saying hello! "); }, BTN, { repeat:true, edge:'falling', debounce:20 });
//Send_SMS("Saying hello ");
}
onInit();

Posted at 2014-07-14 by user7143

sorry about the messed up code format. If someone can tell me what I am doing wrong I will repost it

Posted at 2014-07-14 by @gfwilliams

@user7143 I just fixed it for you. You need three backticks before and after the code. The simplest way is to just highlight the code you paste in and click the button that says </> code at the top of the edit window.

Posted at 2014-07-14 by DrAzzy

The </> code button sometimes refuses to work for me (same with the quote button).

It's 3 backticks: ```
And you need a blank line before the backticks, otherwise they don't seem to work right.

Posted at 2014-07-19 by Hardware_Hacks

@user7143 looking good! Seems like we are getting somewhere now

Posted at 2014-07-20 by Hardware_Hacks

Im going to be building in a basic check to see if the module is on.

You should be able to send the "AT" command and receive an "OK" back. This can then probably be expanded out for most other commands. When a command is issued we can check the response against the expected response and start to handle errors better then.

Posted at 2017-07-21 by @gfwilliams

@Hardware_Hacks did this AT/SMS module ever get anywhere?

Posted at 2017-07-24 by user79451

doesn't seem to be anybody home :(

Would you know where the latest version of the library would be, at the end of the post I guess? Also, was it very specific to the GSM2 Click or should I expect it to work on a SIM800 as well?

I need a worldwide working gsm for sending sms reliably..

Thanks

Posted at 2017-07-24 by @gfwilliams

I think as-is, the code in this post isn't going to be that easy to use... Espruino has an at library built in now, which should make this much tidier.

So I can try and get something working quickly, exactly which functionality did you want? Literally just sending SMS messages, or other things too?

Posted at 2017-07-24 by user79451

Just sending some sensor values by sms would be great. Possible receiving an sms with instructions for turning sensors on or off could be a next step.

Posted at 2017-07-24 by @gfwilliams

Ok, just done! So as not to hijack the thread, I made a new one here: http://forum.espruino.com/conversations/308106/