GPRS or Edge Howto? #5350

espruino-discuss3 · 2025-02-12T14:33:10Z

espruino-discuss3
Feb 12, 2025
Maintainer

Posted at 2014-11-01 by fobus

Hello,

I'm really sorry about this question, may be it is already discussed, but I can't find any answer.

I want to design a simple tracker hardware that sends location data to server over "http", Location data will be gathered from GPS module (http://www.espruino.com/GPS) but I can't find a GPS or EDGE module. Is there a gprs or edge module to connect the device to internet?

Thanks all.

espruino-discuss3 · 2025-02-12T14:33:13Z

espruino-discuss3
Feb 12, 2025
Maintainer Author

Posted at 2014-11-01 by @allObjects

CC3000 module provides this connectivity - see http://www.espruino.com/CC3000. It's on my list. The GPS part I have implemented - see http://forum.espruino.com/conversations/255759/. If got the CC3300 Wifi board a while ago, but I'm working on some other items right now - last but not least because default connectivity for my display and and are using the same SPI and control pins.

Posted at 2014-11-01 by @gfwilliams

Right now I don't have a GPRS/EDGE module that I've tested (or have modules for) I'm afraid. It's on my list of things to get and try out though.

It seems like a lot of GPRS modules use AT commands to allow you to make TCPIP connections, and they're very similar to the ESP8266 discussed here - there's some code at that link to make an HTTP connection to the module and it should be pretty easy to modify it so you can use it with a GPRS module.

I'll be adding support for the ESP8266 to Espruino itself quite soon, and I plan to make sure it'll work with a GPRS module too.

By the way there's also some code here to handle SMS text messages, so you could always send readings via that (although that probably isn't what you want).

Posted at 2014-12-10 by net-tobi

Hello,

are there any news regarding the support of a GPRS module? Which module would you suggest?

We are highly interested in using Espruino in combination with a GPRS module for one of our projects. The idea is to build an Espruino based Sensor device which can be used in an outdoor area. The device shall deliver Sensor data to our Servers in the Cloud via GPRS.

Best,

Tobias

Posted at 2014-12-10 by @gfwilliams

Hi net-tobi,

At the moment there is no built-in GPRS module support (except for some code on the forums for sending text messages)... But as I'm adding ESP8266 WiFi support, and the protocol is similar (but not identical) to many GPRS modules, I'll be adding proper support in maybe 3 months' time.

The module that I will be getting working is the one that seems to get used a lot with Arduino - the SIM900A.

Right now you can still use this module with Espruino - you'll just have to write some code to drive it. You wouldn't be able to use Espruino's built-in HTTP client and server, but it would be pretty easy to get enough working to send data to a server in the cloud.

If you're interested I can give you some pointers?

Posted at 2014-12-11 by net-tobi

Hi Gordon,

thank you for your fast response. For the device prototype I start using a WiFi module now.

The final version will use a GPRS module when it is offically supported.

Best,

Tobias

Posted at 2015-03-02 by net-tobi

Any news about the implementation of GPRS support?

Posted at 2015-03-02 by @gfwilliams

Not really I'm afraid. I've been experimenting with finding a way to create something common to ESP8266 and GPRS, and it looks very promising. I now have a SIM900 module (seems common for Arduino) here that I'll be using to develop with when I get time though.

Someone else is actually developing support for their own product and seems happy to contribute back, so hopefully they will share some of their code soon too.

For the next few weeks at least I have to focus on the Pico, but after that I should have more time to get this sorted. Sorry about the delay...

Posted at 2015-03-09 by @joakim

I'd be interested in learning what product that is, if you can share that with us? :)

One alternative for 2G/3G connectivity is SparqEE CELL, it seems pretty easy to work with over UART:
http://www.sparqee.com/portfolio/sparqee-cell/

It comes with a SparqeeSIM card, and their plans are actually very cheap if you send very little data. And unlike a few other solutions, it works almost everywhere (with increasing price though):
http://www.sparqsim.com/

Posted at 2015-03-15 by user49225

For me GPRS is a must.. Sparqee looks interesting

Posted at 2015-03-16 by net-tobi

For me it is very important as well

Posted at 2015-03-16 by @gfwilliams

@cknight posted up about his project here: http://forum.espruino.com/conversations/264103/

I'm actually working on this now, and have Espruino calling into JS for network access. I'll get it working with the ESP8266 first, and will then tweak it for the SIM900.

Posted at 2015-03-26 by @joakim

This one just came out:
https://www.kickstarter.com/projects/konekt/konekt-dash-cellular-dev-kit-free-global-data-plan/

Cellular modules are getting cheaper! The Dash is just $49 for early birds, and their global SIM is much cheaper than SparqSIM. $1/1MB/month is pretty nice, or even $0.55/500K/month!

Incidentally, Konekt is what SparqSIM actually uses behind the scenes. I guess the Konekt guys saw the interest around SparqEE and thought they could do it even cheaper and better.

Posted at 2015-03-26 by @joakim

Hm, the Dash has a Cortex M4, 12 analog inputs and 31 GPIOs. Doesn't say which exact chip it has, but "it works like an Arduino". Should be possible to run Espruino directly on the module right..??

Posted at 2015-03-26 by @joakim

There's also the conspicuously similar Spark Electron:
https://www.kickstarter.com/projects/sparkdevices/spark-electron-cellular-dev-kit-with-a-simple-data?ref=users

But it's not dual 2G/3G, it's monthly rates are 3 times as high as Konekt's, and it's not active in as many countries. No thanks.

Posted at 2015-03-26 by @gfwilliams

Hmm, I wonder what the chip is in the Konekt - they talk of Python so it might be running Micro Python... $0.55/mo is really exciting though - if that's actually not just a 'KickStarter special' it'll be the start of a lot more people using it. 500K is absolutely loads for embedded stuff.

The modules must be able to get cheaper too - the SIM900s modules on eBay are £12 each, and it wouldn't cost much to shove an ARM on one of them.

Posted at 2015-03-26 by @joakim

I just noticed some specs for the chip: "Cortex M4 1MB, 16 MHz, 32.768 KHz, Sleep Timer". Does that offer you any clues? They also say:

It works like an Ardunio and can run Wiring, Python, ARM assembly or whatever code you'd like to use. It's open source, and infinitely hackable, so you can easily adjust and build the Dash into any of your own projects

You're right about SIM900, but it's only 2G, which is already being phased out in the US and Australia, and possibly other regions to follow soon. So SIM900 isn't really an option for me, at least not if you're creating a product to be used in various countries.

(Makes you wonder how long 3G has left..)

Dash uses u-blox Sara which is 2G+3G, but it has variants for either Americas or Europe/Asia and I don't know which one it is (I just asked on Kickstarter). Dash Pro uses u-blox Lisa which is 3.75G and works just about all over the world. One thing is certain, the world of mobile networks is messy.

Posted at 2015-03-26 by LawrenceG

It's not just Konekt hardware it's their whole platform that excites me. I've got some of their SIMs and should be able to test the beta platform next week so will let you know how I get on. BTW I had to draw this diagram to get my head around their platform http://industrialinternet.co.uk/iot-2/konekt-io-architecture it might be of help to others.

Posted at 2015-03-27 by @gfwilliams

It looks very cool to have a platform that can take SMS as well as TCP/IP - that's perfect for a lot of us, as you can get pay as you go SIMs with sensible price text messages in every high street shop.

The think I don't get is that u-blox Lisa is crazy expensive - €150 one-off. They must have a massive volume discount available.

Posted at 2015-03-27 by LawrenceG

Part of the cost issue is carrier approval for the modem/device. In the EU telcos require GCF approval http://www.globalcertificationforum.org/ of at least the modem and increasingly the device (Dash/Electron etc.) before it's approved.

With high street PAYG SIMS you don't get any SIM management tools as you do with M2M sims. My M2M provider charges £3.30 a month for 1Mb for a Global SIM. Also most M2M providers don't like talking to me as I'm a one-man-band not some "big corp". For me Konekt/Electron are like citizen band for the IoT.

Posted at 2015-03-27 by @joakim

@lawrenceG Thanks for sharing the diagram, Konekt looks like a great platform when you see it all together like that! It's really worth it just to have all that abstracted away for you, and you get to focus on the fun stuff.

@gfwilliams Lisa sells for just €43.99 here, and you can get Sara for €10 less. (Nice names for modules, but that sounded a bit odd.)

Btw, I got an answer from Konekt. They'll let backers pick which variant of Sara they want, meaning which region the Dash should work in. (Dash Pro is worldwide though.)

Posted at 2015-04-21 by net-tobi

Any news on the official GPRS support (SIM900 module)? I saw a remark in the issue list on GitHub about that, a few weeks ago.

Posted at 2015-04-21 by @gfwilliams

@net-tobi - not there yet. It's on my desk but I haven't been able to find the SIM I had kicking around (and my phone's one didn't work for me). I'll get it done during the next month I hope.

However things have moved on - it's actually at the stage where someone else could easily do it now if I'm taking too long. The ESP8266 driver is all JavaScript, and hopefully isn't too painful to figure out. All the AT command handling is there already.

So basically all you have to do is take that file and modify it for the SIM900, which is remarkably similar... datasheet here - take a look at Chapter 8 (TCPIP)

Posted at 2015-05-18 by net-tobi

Is there someone in the community who already implemented a working driver for the SIM900a module based on NetworkJS?

Posted at 2015-05-18 by @gfwilliams

I bought a sim card over the weekend and am looking at it this morning.

It turns out that the SIM900A doesn't work in the UK out of the box and you've got to update the firmware though - which I'm still struggling to do.

Posted at 2015-05-18 by @gfwilliams

Hmm - well that was a waste of a morning. Looks like my module is dead. It couldn't see any cell towers and it couldn't read the SIM card, even after a firmware update.

I've just ordered a different SIM900 module, so hopefully I'll have more luck with that.

Posted at 2015-05-18 by net-tobi

Oh... this is annoying. Which module do you exactly have? I have this one:

http://imall.iteadstudio.com/im140318007.html

This is pretty good.

Posted at 2015-05-19 by @gfwilliams

That one looks good - mine was a very cheap Chinese one off eBay. The simple way to check is to put a SIM card in, plug it into power, and then see if after a while the light goes from blinking every 0.8s to blinking every 3 sec. Mine never did :)

Posted at 2015-06-01 by net-tobi

Hello all, I started writing a driver for the SIM900A today based on the ESP8266 driver.

init is working
connect is working
getIP is working
reset is just calling init currently because I didn't find a way to reset the SIM900 by using an AT-command (for ESP8266 there is AT+RST)

I got stuck at sending a HTTP-Request through NetworkJS. What happens is, that the send-method is called over and over and after a few retries it stops. I can not see any response from the server currently. I assume that there are subtle differences in the use of the AT+CIPSEND command for ESP8266 and SIM900A. Any ideas?

Here you find the code:

Serial1.setup(115200, { rx: B7, tx : B6 });


var at;
var socks = [];
var sockData = ["","","","",""];
var MAXSOCKETS = 5;

var netCallbacks = {
  create : function(host, port) {
    /* Create a socket and return its index, host is a string, port is an integer.
    If host isn't defined, create a server socket */  
    if (host===undefined) {
      sckt = MAXSOCKETS;
      socks[sckt] = "Wait";
      sockData[sckt] = "";
      at.cmd("AT+CIPSERVER=1,"+port+"\r\n", 10000, function(d) {
        if (d=="OK") {
          socks[sckt] = true;
        } else {
          socks[sckt] = undefined;
          throw new Error("CIPSERVER failed");
        }
      });
      return MAXSOCKETS;
    } else {
      var sckt = 0;
      while (socks[sckt]!==undefined) sckt++; // find free socket
      if (sckt>=MAXSOCKETS) throw new Error("No free sockets");
      socks[sckt] = "Wait";
      sockData[sckt] = "";
      at.cmd('AT+CIPSTART='+sckt+',"TCP",'+JSON.stringify(host)+','+port+'\r\n',10000, function(d) {
        if (d=="OK") {
          at.registerLine(sckt + ', CONNECT OK', function() {
            at.unregisterLine(sckt + ', CONNECT OK');
            socks[sckt] = true;
          });
          at.registerLine(sckt + ', CLOSED', function() {
            at.unregisterLine(sckt + ', CLOSED');
            socks[sckt] = undefined;
          });
        } else {
          socks[sckt] = undefined;
          throw new Error("CIPSTART failed");
        }
      });
    }
    return sckt;
  },
  /* Close the socket. returns nothing */
  close : function(sckt) {    
    at.cmd('AT+CIPCLOSE='+sckt+"\r\n",1000, function(/*d*/) {
      socks[sckt] = undefined;
      //console.log("?"+JSON.stringify(d));
    });
  },
  /* Accept the connection on the server socket. Returns socket number or -1 if no connection */
  accept : function(sckt) {
    // console.log("Accept",sckt);
    for (var i=0;i<MAXSOCKETS;i++)
      if (sockData[i] && socks[i]===undefined) {
        //console.log("Socket accept "+i,JSON.stringify(sockData[i]),socks[i]);
        socks[i] = true;
        return i;
      }
    return -1;
  },
  /* Receive data. Returns a string (even if empty).
  If non-string returned, socket is then closed */
  recv : function(sckt, maxLen) {    
    if (at.isBusy() || socks[sckt]=="Wait") return "";
    if (sockData[sckt]) {
      var r;
      if (sockData[sckt].length > maxLen) {
        r = sockData[sckt].substr(0,maxLen);
        sockData[sckt] = sockData[sckt].substr(maxLen);
      } else {
        r = sockData[sckt];
        sockData[sckt] = "";
      }
      return r;
    }
    if (!socks[sckt]) return -1; // close it
    return "";
  },
  /* Send data. Returns the number of bytes sent - 0 is ok.
  Less than 0  */
  send : function(sckt, data) {
    console.log(data);
    if (at.isBusy() || socks[sckt]=="Wait") return 0;
    if (!socks[sckt]) return -1; // error - close it
    console.log("Send: " + data);
    var f = function(d) {
      // TODO: register for '>'
      //console.log("?"+JSON.stringify(d));
      if (d=="> ") {
        return f;
      }
    };
    at.cmd('AT+CIPSEND='+sckt+','+data.length+'\r\n' + data , 10000, f);
    return data.length;
  }
};


//Handle +IPD input data from SIM900A
function ipdHandler(line) {
  var colon = line.indexOf(":");
  if (colon<0) return line; // not enough data here at the moment
  var parms = line.substring(5,colon).split(",");
  parms[1] = 0|parms[1];
  var len = line.length-(colon+1);
  if (len>=parms[1]) {
   // we have everything
   sockData[parms[0]] += line.substr(colon+1,parms[1]);
   return line.substr(colon+parms[1]+1); // return anything else
  } else { 
   // still some to get
   sockData[parms[0]] += line.substr(colon+1,len);
   return "+IPD,"+parms[0]+","+(parms[1]-len)+":"; // return IPD so we get called next time    
  }
}

var gprsFuncs = {
  ipdHandler:ipdHandler,
  "debug" : function() {
    return {
      socks:socks,
      sockData:sockData
    };
  },
  // initialise the SIM900A
  "init" : function(callback) { 
    var s = 0;
    var cb = function(r) {
      console.log(r);
      switch(s) {
        case 0:
          if(r === 'ATE0' || r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 1;
            at.cmd('AT+CPIN?\r\n', 100, cb);
          }
          break;
        case 1:
          if(r === '+CPIN: READY' || r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 2;
            at.cmd('AT+CGATT?\r\n', 100, cb);
          }
          break;
        case 2:
          if(r === '+CGATT: 1' || r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 3;
            at.cmd('AT+CIPSHUT\r\n', 100, cb);
          }
          break;
        case 3:
          if(r === 'SHUT OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 4;
            at.cmd('AT+CIPSTATUS\r\n', 100, cb);
          }
          break;
        case 4:
          if(r === 'STATE: IP INITIAL' || r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 5;
            at.cmd('AT+CIPMUX=1\r\n', 100, cb);
          }
          break;
        case 5:
          if(r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            callback(null);
          }
          break;
      }
      return cb;
    };
    at.cmd("ATE0\r\n",1000,cb);
  },
  "reset" : function(callback) {
    gprsFuncs.init(callback);
  },
  "getVersion" : function(callback) {
    at.cmd("AT+GMR\r\n", 1000, function(d) {
      callback(null,d);
    });
  },
  "connect" : function(apn, username, password, callback) {
    var s = 0;
    var cb = function(r) {
      switch(s) {
        case 0:
          if(r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 1;
            at.cmd('AT+CIICR\r\n', 2000, cb);
          }
          break;
        case 1:
          if(r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            callback(null);
          }
          break;
      }
    };
    at.cmd('AT+CSTT="' + apn + '", "' + username + '", "' + password + '"\r\n', 1000, cb);
  },
  "getIP" : function(callback) {
    var ip;
    var cb = function(r) {
      if(r && r != 'ERROR') {
        ip = r;
        return cb;
      } else if(r === 'ERROR') {
        callback('CIFSR Error');
      } else if(!r) {
        callback(null, ip);
      }
    };
    at.cmd('AT+CIFSR\r\n', 2000, cb);
  }
};
var connect = function(usart, connectedCallback) {
  gprsFuncs.at = at = require("AT").connect(usart);
  require("NetworkJS").create(netCallbacks);
  at.register("+IPD", ipdHandler);
  gprsFuncs.reset(connectedCallback);
  return gprsFuncs;
};

connect(Serial1, function() {
  gprsFuncs.connect('pinternet.interkom.de', '', '', function(err) {
    console.log(err);
    gprsFuncs.getIP(function(err, ip) {
      console.log('IP:' + ip);
      require("http").get("http://www.pur3.co.uk/hello.txt", function(res) {
        console.log("Response: ",res);
        res.on('data', function(d) {
          console.log("--->"+d);
        });
      });
    });
  });
});

Posted at 2015-06-02 by @gfwilliams

What get shown when you call gprsFuncs.at.debug()? From what I can see, it looks like CIPSEND behaves the same way when CIPMUX=1 was used - which is was in your case. It's possible it doesn't like the newline after \r though... It should return SEND OK if all has gone well.

It looks like it might just send back the result data without +IPD, which would make it harder for Espruino to get the data.

I think you need to send the AT+CIPHEAD=1 command when initialising to make sure that +IPD gets prepended to any data.

Posted at 2015-06-02 by net-tobi

I think the problem is within the AT lib. It just handles lines which end with \r\n. On the SIM900 you have to wait for "> " before sending the data after sending AT+CIPSEND=...

The "> " is not ending with \r\n therefore it is not sent back to the callback provided to at.cmd()

My send method currently looks like this:

  send : function(sckt, data) {
    if (at.isBusy() || socks[sckt]=="Wait" || sockBusy[sckt]) return 0;
    if (!socks[sckt]) return -1; // error - close it
    sockBusy[sckt] = true;

    var cb = function(r) {
      at.debug();
      console.log('-->' + JSON.stringify(r));
      return cb;
    };
    sockSent[sckt] += data.length;
    console.log('Send '+ data.length + ': ' + JSON.stringify(data));
    console.log('Total: ' + sockSent[sckt]);
    at.cmd('AT+CIPSEND='+sckt+','+data.length+'\r\n', 3000, cb);
    return sockSent[sckt];
  }

Posted at 2015-06-02 by net-tobi

I added the CIPHEAD=1 setting to init and I took the send method of the ESP8266 driver now and I call at.debug() in the callback.

It now looks like this:

  send : function(sckt, data) {
    if (at.isBusy() || socks[sckt]=="Wait") return 0;
    if (!socks[sckt]) return -1; // error - close it
    var f = function(d) {
      console.log(d);
      at.debug();
      if (d=="> ") return f;
    };
    at.cmd('AT+CIPSEND='+sckt+','+data.length+'\r\n'+data, 10000, f);
    return data.length;
  }

The output is the following:

 _____                 _
|   __|___ ___ ___ _ _|_|___ ___
|   __|_ -| . |  _| | | |   | . |
|_____|___|  _|_| |___|_|_|_|___|
          |_| http://espruino.com
 1v80 Copyright 2015 G.Williams
>echo(0);
=undefined
null
IP:10.54.158.176
undefined
["AT+CIPSEND=0,31\r\nclose\r\nHost: www.pur3.co.uk\r\n\r\n"
] "> \r\n0" <--- "\r\n0"
>
] "0, CLOSED\r\n\r\nERROR\r\n" <--- ", CLOSED\r\n\r\nERROR\r\n"
ERROR
["AT+CIPCLOSE=0\r\n"
] "\r" <--- "\r"
] "\nERROR\r\n" <--- "\nERROR\r\n"
>

Posted at 2015-06-02 by @gfwilliams

You probably want to call at.debug(); before CIPSTART, just so you can see what's being sent back a bit sooner.

It looks to me like the CIPSEND command itself is working, but the connection has already been closed by the server - hence the CLOSED message?

While the AT command module doesn't have an easy way to respond to just >, I don't think you have to worry. It basically always sends > so you can pretty much ignore having to wait for it and just keep sending data.

Posted at 2015-06-02 by net-tobi

Hello again,

the entire at.debug() trace is the following:

 _____                 _
|   __|___ ___ ___ _ _|_|___ ___
|   __|_ -| . |  _| | | |   | . |
|_____|___|  _|_| |___|_|_|_|___|
          |_| http://espruino.com
 1v80 Copyright 2015 G.Williams
>echo(0);
=undefined
["AT+CPIN?\r\n"
] "\r" <--- "\r"
] "\n+CPIN: READY\r\n\r\nOK\r\n" <--- "\n+CPIN: READY\r\n\r\nOK\r\n"
["AT+CGATT?\r\n"
] "\r" <--- "\r"
] "\n+CGATT: 1\r\n\r\nOK\r\n" <--- "\n+CGATT: 1\r\n\r\nOK\r\n"
["AT+CIPSHUT\r\n"
] "\r" <--- "\r"
] "\nSHUT OK\r\n" <--- "\nSHUT OK\r\n"
["AT+CIPSTATUS\r\n"
] "\r" <--- "\r"
] "\nOK\r\n\r\nSTATE: IP INITIAL\r\n" <--- "\nOK\r\n\r\nSTATE: IP INITIAL\r\n"
["AT+CIPMUX=1\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
["AT+CIPHEAD=1\r\n"
] "\r\n" <--- "\r\n"
] "OK\r\n" <--- "OK\r\n"
["AT+CSTT=\"pinternet.interkom.de\", \"\", \"\"\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
["AT+CIICR\r\n"
] "\r\n" <--- "\r\n"
] "OK\r\n" <--- "OK\r\n"
null
["AT+CIFSR\r\n"
] "\r" <--- "\r"
] "\n10.50.96.30\r\n" <--- "\n10.50.96.30\r\n"
IP:10.50.96.30
["AT+CIPSTART=0,\"TCP\",\"www.pur3.co.uk\",80\r\n"
] "\r\nOK\r\n" <--- "\r\nOK\r\n"
] "\r\n0" <--- "\r\n0"
] "0, CONNECT OK\r\n" <--- ", CONNECT OK\r\n"
["AT+CIPSEND=0,64\r\nGET /hello.txt HTTP/1.0\r\nUser-Agent: Espruino 1v80\r\nConnection: "
] "\r\n> " <--- "\r\n> "
["AAT+CIPSEND=0,31\r\nclose\r\nHost: www.pur3.co.uk\r\n\r\n"
] "> \r\n0, CLOSE" <--- "\r\n0, CLOSE"
] "0, CLOSED\r\n\r\nERROR\r\n" <--- "D\r\n\r\nERROR\r\n"
["AT+CIPCLOSE=0\r\n"
] "\r\n" <--- "\r\n"
] "ERROR\r\n" <--- "ERROR\r\n"
>

Posted at 2015-06-02 by net-tobi

I cannot see any "0, SEND OK" responses and I currently have no idea why.

Posted at 2015-06-02 by @gfwilliams

Thanks - as you say, no response even to the first CIPSEND.

Have you tried just sending the CIPSEND command manually and seeing if you can get it to go sending something simple? It might be it wants a newline after the text that's sent?

The other option is to go for Ctrl+Z terminated mode:

  send : function(sckt, data) {
    if (at.isBusy() || socks[sckt]=="Wait") return 0;
    if (!socks[sckt]) return -1; // error - close it
    var f = function(d) {
      if (d=="> ") return f;
    };
    at.cmd('AT+CIPSEND='+sckt+'\r\n'+data+"\x1A"/*ctrl+z*/, 10000, f);
    return data.length;
  }

That'd be easier but will cause you problems if you want to send binary data.

Posted at 2015-06-02 by net-tobi

Hello again,

I tried it manually. When I wait for the "> " to appear, it works:

["AT+CIPSTART=0,\"TCP\",\"www.pur3.co.uk\",80\r\n"
=0
] "\r\n" <--- "\r\n"
] "OK\r\n" <--- "OK\r\n"
] "\r" <--- "\r"
] "\n0, CONNECT OK\r\n" <--- "\n0, CONNECT OK\r\n"
>at.cmd('AT+CIPSEND=0,5\r\n');
["AT+CIPSEND=0,5\r\n"
=undefined
] "\r" <--- "\r"
] "\n> " <--- "\n> "
>at.cmd('HELLO');
["HELLO"
=undefined
] "> \r" <--- "\r"
] "\n0, SEND OK\r\n" <--- "\n0, SEND OK\r\n"
] "\r" <--- "\r"
] "\n0, CLOSED\r\n" <--- "\n0, CLOSED\r\n"

Do you have an idea how I can wait for "> " using the AT-lib?

Best,

Tobias

Posted at 2015-06-02 by @gfwilliams

Ok, great! Yes, It's possible using register - I'll just try and come up with some code for you.

Posted at 2015-06-02 by @gfwilliams

Ok, turns out there's a very annoying bug in the interpreter! > is used as a character that prefixes internal variables that users don't want to see, and it means it gets ignored when it's in an array. I've just pushed out a new AT module with a workaround in.

Try:

send : function(sckt, data) {
    if (at.isBusy() || socks[sckt]=="Wait") return 0;
    if (!socks[sckt]) return -1; // error - close it
    var f = function(d) {
      at.unregister(">");
      if (d!="SEND OK") console.log("Send got: "+d);
    };
    at.register(">", function() {
      at.write(data);
      return "";
    });
    at.cmd('AT+CIPSEND='+sckt+','+data.length+'\r\n', 10000, f);
    return data.length;
  }

Posted at 2015-06-02 by net-tobi

Thank you Gordon. I tried it, but it doesn't work for me :(

["AT+CPIN?\r\n"
] "\r" <--- "\r"
] "\n+CPIN: READY\r\n\r\nOK\r\n" <--- "\n+CPIN: READY\r\n\r\nOK\r\n"
["AT+CGATT?\r\n"
] "\r" <--- "\r"
] "\n+CGATT: 1\r\n\r\nOK\r\n" <--- "\n+CGATT: 1\r\n\r\nOK\r\n"
["AT+CIPSHUT\r\n"
] "\r" <--- "\r"
] "\nSHUT OK\r\n" <--- "\nSHUT OK\r\n"
["AT+CIPSTATUS\r\n"
] "\r\n" <--- "\r\n"
] "OK\r\n\r\nSTATE: IP INITIAL\r\n" <--- "OK\r\n\r\nSTATE: IP INITIAL\r\n"
["AT+CIPMUX=1\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
["AT+CIPHEAD=1\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
["AT+CSTT=\"pinternet.interkom.de\", \"\", \"\"\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
["AT+CIICR\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
null
["AT+CIFSR\r\n"
] "\r" <--- "\r"
] "\n10.37.76.134\r\n" <--- "\n10.37.76.134\r\n"
IP:10.37.76.134
["AT+CIPSTART=0,\"TCP\",\"www.pur3.co.uk\",80\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
] "\r\n0, CONNECT O" <--- "\r\n0, CONNECT O"
] "0, CONNECT OK\r\n" <--- "K\r\n"
["AT+CIPSEND=0,64\r\n"
] "\r\n> " <--- "\r\n> "
Send got: undefined
["AT+CIPSEND=0,31\r\n"
] "> \r\n" <--- "\r\n"
] "0, CLOSED\r\n\r\nERROR\r\n" <--- "0, CLOSED\r\n\r\nERROR\r\n"
Send got: ERROR
["AT+CIPCLOSE=0\r\n"
] "\r\n" <--- "\r\n"
] "ERROR\r\n" <--- "ERROR\r\n"
>

Posted at 2015-06-02 by @gfwilliams

Can you add some debug code to make sure the register(">" handler is getting called?

It looks possible it's getting confused by the leading newlines. You could hack it in for now by changing the line to:

at.register("\r\n>", function() {

I'll see about modifying the AT command thing a bit more

Posted at 2015-06-02 by @gfwilliams

Ok, maybe try now - without the \r\n>?

Posted at 2015-06-02 by net-tobi

Great to see good progress :)

I should react somewhere to "0, CLOSE". What I do not see currently is that the responses which are coming in are sent back to the HTTP-Lib.

 _____                 _
|   __|___ ___ ___ _ _|_|___ ___
|   __|_ -| . |  _| | | |   | . |
|_____|___|  _|_| |___|_|_|_|___|
          |_| http://espruino.com
 1v80 Copyright 2015 G.Williams
>echo(0);
=undefined
["AT+CPIN?\r\n"
] "\r" <--- "\r"
] "\n+CPIN: READY\r\n\r\nOK\r\n" <--- "\n+CPIN: READY\r\n\r\nOK\r\n"
["AT+CGATT?\r\n"
] "\r" <--- "\r"
] "\n+CGATT: 1\r\n\r\nOK\r\n" <--- "\n+CGATT: 1\r\n\r\nOK\r\n"
["AT+CIPSHUT\r\n"
] "\r" <--- "\r"
] "\nSHUT OK\r\n" <--- "\nSHUT OK\r\n"
["AT+CIPSTATUS\r\n"
] "\r" <--- "\r"
] "\nOK\r\n\r\nSTATE: IP INITIAL\r\n" <--- "\nOK\r\n\r\nSTATE: IP INITIAL\r\n"
["AT+CIPMUX=1\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
["AT+CIPHEAD=1\r\n"
] "\r\n" <--- "\r\n"
] "OK\r\n" <--- "OK\r\n"
["AT+CSTT=\"pinternet.interkom.��@�\� üÍ ñÿÿ] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
["AT+CIICR\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
null
["AT+CIFSR\r\n"
] "\r\n" <--- "\r\n"
] "10.49.128.77\r\n" <--- "10.49.128.77\r\n"
IP::10.49.128.77
["AT+CIPSTART=0,\"TCP\",\"www.pur3.co.uk\",80\r\n"
] "\r\nOK\r\n" <--- "\r\nOK\r\n"
] "\r\n0, CONN" <--- "\r\n0, CONN"
] "0, CONNECT OK\r\n" <--- "ECT OK\r\n"
["AT+CIPSEND=0,64\r\n"
] "\r\n> " <--- "\r\n> "
] "\r\n0, SEND OK\r\n" <--- "\r\n0, SEND OK\r\n"
Send got: 0, SEND OK
["AT+CIPSEND=0,31\r\n"
] "\r\n" <--- "\r\n"
] "> " <--- "> "
] "\r\n0," <--- "\r\n0,"
] "0, SEND OK\r\n" <--- " SEND OK\r\n"
Send got: 0, SEND OK
] "\r\n+RECEIVE," <--- "\r\n+RECEIVE,"
] "+RECEIVE,0,289:\r\nHTTP/1.1 200 OK\r\nDate: Tue, 02 Jun" <--- "0,289:\r\nHTTP/1.1 200 OK\r\nDate: Tue, 02 Jun"
] "Date: Tue, 02 Jun 2015 14:39:12 GMT\r\nServer: Apache/2.2.14 (Ubuntu)\r\nLast-Modified: Fri, 15 Nov 2013 " <--- " 2015 14:39:12 GMT\r\nServer: Apache/2.2.14 (Ubuntu)\r\nLast-Modified: Fri, 15 Nov 2013 "
] "Last-Modified: Fri, 15 Nov 2013 15:42:26 GMT\r\nETag: \"c01036-d-4eb390b8a8d18\"\r\nAccept-Ranges: bytes\r\nContent-Length: 13\r\nVary: Accept-Encoding\r\nC" <--- "15:42:26 GMT\r\nETag: \"c01036-d-4eb390b8a8d18\"\r\nAccept-Ranges: bytes\r\nContent-Length: 13\r\nVary: Accept-Encoding\r\nC"
] "Connection: close\r\nContent-Type: text/plain\r\n\r\nHello World!\n" <--- "onnection: close\r\nContent-Type: text/plain\r\n\r\nHello World!\n"
] "Hello World!\n\r\n0" <--- "\r\n0"
] "0, CLOSED\r\n" <--- ", CLOSED\r\n"
["AT+CIPCLOSE=0\r\n"
] "\r\n" <--- "\r\n"
] "ERROR\r\n" <--- "ERROR\r\n"
>

Posted at 2015-06-02 by net-tobi

Closing is as well now working well. Do you have an idea why the response doesn't show up in the HTTP lib?

Here is the entire code:

Serial1.setup(115200, { rx: B7, tx : B6 });


var at;
var socks = [];
var sockData = ["","","","",""];

var MAXSOCKETS = 5;

var netCallbacks = {
  create : function(host, port) {
    /* Create a socket and return its index, host is a string, port is an integer.
    If host isn't defined, create a server socket */  
    if (host===undefined) {
      sckt = MAXSOCKETS;
      socks[sckt] = "Wait";
      sockData[sckt] = "";
      at.cmd("AT+CIPSERVER=1,"+port+"\r\n", 10000, function(d) {
        if (d=="OK") {
          socks[sckt] = true;
        } else {
          socks[sckt] = undefined;
          throw new Error("CIPSERVER failed");
        }
      });
      return MAXSOCKETS;
    } else {
      var sckt = 0;
      while (socks[sckt]!==undefined) sckt++; // find free socket
      if (sckt>=MAXSOCKETS) throw new Error("No free sockets");
      socks[sckt] = "Wait";
      sockData[sckt] = "";
      at.cmd('AT+CIPSTART='+sckt+',"TCP",'+JSON.stringify(host)+','+port+'\r\n',10000, function(d) {
        at.debug();
        if (d=="OK") {
          at.registerLine(sckt + ', CONNECT OK', function() {
            at.unregisterLine(sckt + ', CONNECT OK');
            socks[sckt] = true;
          });
          at.registerLine(sckt + ', CLOSED', function() {
            at.unregisterLine(sckt + ', CLOSED');
            socks[sckt] = undefined;
          });
        } else {
          socks[sckt] = undefined;
          throw new Error("CIPSTART failed");
        }
      });
    }
    return sckt;
  },
  /* Close the socket. returns nothing */
  close : function(sckt) {
    if(socks[sckt]) {
      at.cmd('AT+CIPCLOSE='+sckt+"\r\n",1000, function(/*d*/) {
      socks[sckt] = undefined;
      });
    }
  },
  /* Accept the connection on the server socket. Returns socket number or -1 if no connection */
  accept : function(sckt) {
    // console.log("Accept",sckt);
    for (var i=0;i<MAXSOCKETS;i++)
      if (sockData[i] && socks[i]===undefined) {
        //console.log("Socket accept "+i,JSON.stringify(sockData[i]),socks[i]);
        socks[i] = true;
        return i;
      }
    return -1;
  },
  /* Receive data. Returns a string (even if empty).
  If non-string returned, socket is then closed */
  recv : function(sckt, maxLen) {
    if (at.isBusy() || socks[sckt]=="Wait") return "";
    if (sockData[sckt]) {
      var r;
      if (sockData[sckt].length > maxLen) {
        r = sockData[sckt].substr(0,maxLen);
        sockData[sckt] = sockData[sckt].substr(maxLen);
      } else {
        r = sockData[sckt];
        sockData[sckt] = "";
      }
      return r;
    }
    if (!socks[sckt]) return -1; // close it
    return "";
  },
  /* Send data. Returns the number of bytes sent - 0 is ok.
  Less than 0  */
  send : function(sckt, data) {
    if (at.isBusy() || socks[sckt]=="Wait") return 0;
    if (!socks[sckt]) return -1; // error - close it
    var f = function(d) {
      at.unregister(">");
      if (d!="SEND OK") console.log("Send got: "+d);
    };
    at.register(">", function() {
      at.write(data);
      return "";
    });
    at.cmd('AT+CIPSEND='+sckt+','+data.length+'\r\n', 10000, f);
    return data.length;
  }
};


//Handle +IPD input data from SIM900A
function ipdHandler(line) {
  var colon = line.indexOf(":");
  if (colon<0) return line; // not enough data here at the moment
  var parms = line.substring(5,colon).split(",");
  parms[1] = 0|parms[1];
  var len = line.length-(colon+1);
  if (len>=parms[1]) {
   // we have everything
   sockData[parms[0]] += line.substr(colon+1,parms[1]);
   return line.substr(colon+parms[1]+1); // return anything else
  } else { 
   // still some to get
   sockData[parms[0]] += line.substr(colon+1,len);
   return "+IPD,"+parms[0]+","+(parms[1]-len)+":"; // return IPD so we get called next time    
  }
}

var gprsFuncs = {
  ipdHandler:ipdHandler,
  "debug" : function() {
    return {
      socks:socks,
      sockData:sockData
    };
  },
  // initialise the SIM900A
  "init" : function(callback) {
    var s = 0;
    var cb = function(r) {
      at.debug();
      switch(s) {
        case 0:
          if(r === 'ATE0' || r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 1;
            at.cmd('AT+CPIN?\r\n', 100, cb);
          }
          break;
        case 1:
          if(r === '+CPIN: READY' || r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 2;
            at.cmd('AT+CGATT?\r\n', 100, cb);
          }
          break;
        case 2:
          if(r === '+CGATT: 1' || r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 3;
            at.cmd('AT+CIPSHUT\r\n', 100, cb);
          }
          break;
        case 3:
          if(r === 'SHUT OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 4;
            at.cmd('AT+CIPSTATUS\r\n', 100, cb);
          }
          break;
        case 4:
          if(r === 'STATE: IP INITIAL' || r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 5;
            at.cmd('AT+CIPMUX=1\r\n', 100, cb);
          }
          break;
        case 5:
          if(r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 6;
            at.cmd('AT+CIPHEAD=1\r\n', 100, cb);
          }
          break;
        case 6:
          if(r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            callback(null);
          }
          break;
      }
    };
    at.cmd("ATE0\r\n",1000,cb);
  },
  "reset" : function(callback) {
    gprsFuncs.init(callback);
  },
  "getVersion" : function(callback) {
    at.cmd("AT+GMR\r\n", 1000, function(d) {
      callback(null,d);
    });
  },
  "connect" : function(apn, username, password, callback) {
    var s = 0;
    var cb = function(r) {
      switch(s) {
        case 0:
          if(r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            s = 1;
            at.cmd('AT+CIICR\r\n', 2000, cb);
          }
          break;
        case 1:
          if(r === 'OK') return cb;
          else if(r) {
            callback('Error in ' + s + ': ' + r);
          } else {
            callback(null);
          }
          break;
      }
    };
    at.cmd('AT+CSTT="' + apn + '", "' + username + '", "' + password + '"\r\n', 1000, cb);
  },
  "getIP" : function(callback) {
    var ip;
    var cb = function(r) {
      if(r && r != 'ERROR') {
        ip = r;
        return cb;
      } else if(r === 'ERROR') {
        callback('CIFSR Error');
      } else if(!r) {
        callback(null, ip);
      }
    };
    at.cmd('AT+CIFSR\r\n', 2000, cb);
  }
};
var connect = function(usart, connectedCallback) {
  gprsFuncs.at = at = require("AT").connect(usart);
  require("NetworkJS").create(netCallbacks);
  at.register("+IPD", ipdHandler);
  gprsFuncs.reset(connectedCallback);
  return gprsFuncs;
};

connect(Serial1, function() {
  gprsFuncs.connect('pinternet.interkom.de', '', '', function(err) {
    console.log(err);
    gprsFuncs.getIP(function(err, ip) {
      console.log('IP:' + ip);
      require("http").get("http://www.pur3.co.uk/hello.txt", function(res) {
        console.log("Response: ",res);
        res.on('data', function(d) {
          console.log("--->"+d);
        });
      });
    });
  });
});

Posted at 2015-06-02 by net-tobi

I replaced +IPD by +RECEIVE and the Handler-Function is getting called. But no response is being shown in the HTTP lib

Posted at 2015-06-02 by @gfwilliams

Great! The response is coming back prefixed with +RECEIVE, not +IPD. Seems odd (I'd expected IPD after the call to CIPHEAD), but it can be changed easily...

// Instead of ipdHandler:

//Handle +RECEIVE input data from SIM900A
function receiveHandler(line) {
  var colon = line.indexOf(":");
  if (colon<0) return line; // not enough data here at the moment
  var parms = line.substring(9,colon).split(",");
  parms[1] = 0|parms[1];
  var len = line.length-(colon+1);
  if (len>=parms[1]) {
   // we have everything
   sockData[parms[0]] += line.substr(colon+1,parms[1]);
   return line.substr(colon+parms[1]+1); // return anything else
  } else { 
   // still some to get
   sockData[parms[0]] += line.substr(colon+1,len);
   return "+RECEIVE,"+parms[0]+","+(parms[1]-len)+":"; // return RECEIVE so we get called next time    
  }
}

// ...


var connect = function(usart, connectedCallback) {
  gprsFuncs.at = at = require("AT").connect(usart);
  require("NetworkJS").create(netCallbacks);
  at.register("+RECEIVE", receiveHandler); // <----------------------------
  gprsFuncs.reset(connectedCallback);
  return gprsFuncs;
};

Sorry for not getting this sorted for you last time - I've been a bit busy. I did buy the second GPRS module, from a UK seller, but I still wasn't getting a mobile connection so couldn't get anything working :(

Posted at 2015-06-02 by @gfwilliams

Maybe take a look in the socks array and check that the socket's state isn't wait or something. Also check sockData array to see if the data is getting sent in there.

If the ipdHandler/receiveHandler is working ok the the data should all go into sockData, and the recv function is then responsible for giving that to Espruino.

If you changed the text in ipdHandler, dod you change line.substring(5,colon) to line.substring(9,colon) as well? That could be important...

Posted at 2015-06-03 by @gfwilliams

Did you get this working in the end?

Posted at 2015-06-03 by net-tobi

Hi Gordon,

I am currently testing the driver in my project. When everything is working fine, I'll send you the code of it, so you can publish it as module here, if you like.

Best,

Tobias

Posted at 2015-06-06 by net-tobi

Hello Gordon,

I tested the driver again. I currently have the issue that the http status code is not correctly read by the HTTP lib on close. What I get on a HTTP-Request in res.statusCode is the String "\nHTTP/1.1". Is this a problem with with receiveHandler-Function?

Best,

Tobias

Posted at 2015-06-08 by net-tobi

I have reproducable problems again with the Pico. [CTRL+C] echo(1) doesn't help here. I just get it working when disconnecting it from USB and from the power source. It happens in the sim900 driver when the method init is getting called.

I currently have the problem very often using other code but I was not able to reproduce it.

This is the output (after that it hangs):

 _____                 _
|   __|___ ___ ___ _ _|_|___ ___
|   __|_ -| . |  _| | | |   | . |
|_____|___|  _|_| |___|_|_|_|___|
          |_| http://espruino.com
 1v79.19 Copyright 2015 G.Williams
>echo(0);
=undefined
Inititialize sim900 module
>

As well the Pico sends some weird characters sometimes when connecting it to USB (no init function has been set which could produce that):

Connected
>�à� �Ö���2��|

Posted at 2015-06-08 by net-tobi

Regarding the HTTP Status code: I can see that some of the data is not getting passed correctly to the attributes of the Response-Object. See here:

Response:  {
  "headers": {
    "Date": "Mon, 08 Jun 2015 12:09:31 GMT",
    "Server": "Apache/2.2.14 (Ubuntu)",
    "Last-Modified": "Fri, 15 Nov 2013 15:42:26 GMT",
    "ETag": "\"c01036-d-4eb390b8a8d18\"",
    "Accept-Ranges": "bytes",
    "Content-Length": "13",
    "Vary": "Accept-Encoding",
    "Connection": "close",
    "Content-Type": "text/plain"
   },
  "httpVersion": "P/1.1 200 OK\r\nDate: Mon, 08 Jun 2015 12:09:31 GMT\r\nServer: Apache/2.2.14 (Ubuntu)\r\nLast-Modified: Fri, 15 Nov 2013 15:42:26 GMT\r\nETag: \"c01036-d-4eb390b8a8d18\"\r\nAccept-Ranges: bytes\r\nContent-Length: 13\r\nVary: Accept-Encoding\r\nConnection: close\r\nContent-Type: text/plain\r\n\r\nHello World",
  "statusCode": "\nHTTP/1.1",
  "statusMessage": "200 OK\r\nDate: Mon, 08 Jun 2015 12:09:31 GMT\r\nServer: Apache/2.2.14 (Ubuntu)\r\nLast-Modified: Fri, 15 Nov 2013 15:42:26 GMT\r\nETag: \"c01036-d-4eb390b8a8d18\"\r\nAccept-Ranges: bytes\r\nContent-Length: 13\r\nVary: Accept-Encoding\r\nConnection: close\r\nContent-Type: text/plain\r\n\r\nHello World"
 }

Posted at 2015-06-08 by @gfwilliams

edit: sorry - I didn't see these extra posts until my response appeared. I'll take a look tomorrow.

Posted at 2015-06-08 by net-tobi

Thank you. I attached the most recent version of the sim900 lib.

Regarding the problem that Espruino hangs do you think that has something todo with Serial1 as discussed here?

http://forum.espruino.com/conversations/255152/#comment12325361

I experienced that when I first connect the pico to USB and then start the sim900 module the problem doesn't exist. I'll try to set USB.setConsole() in onInit tomorrow and check if that solves the problem.

Attachments:

sim900a.js

Posted at 2015-06-08 by DrAzzy

I see in there references to username and password - I'm confused, I thought that the SIM900 only required the SIM card. How do you get the APM, username and password?

I'm planning to use one of these once my plan expires so I can get my parents and I onto a family plan so I can get SIMs for less than $40-60/month.

Posted at 2015-06-08 by net-tobi

The apn, username and password depends on the service provider you are using. In the most cases these are the same for all users and you can find it on the support pages of the providers. Here is a list with some apn settings:

http://www.hw-group.com/products/HWg-Ares/HWg-Ares_GSM_APN_en.html

Posted at 2015-06-09 by @gfwilliams

Your hanging could be something to do with the console moving to Serial1 I guess. Have you tried forcing it to USB in onInit?

If some code hung, the the input buffer could get full from the responses from the SIM900, which might mean that Ctrl+C no longer worked. It seems strange though.

The errors you were getting with the newline at the start of the HTTP request - do they also happen on the very first HTTP request you make? I have a hunch that it might be rubbish that's left over from previous HTTP requests.

Posted at 2015-06-09 by net-tobi

Hi Gordon,

the USB.setConsole() in onInit seems to solve the problem. I can't reproduce it now.

Yes the problems with the HTTP request happen in the very first request as well. It's not just the newline. There should be the status code instead of the HTTP version.

Best,

Tobias

Posted at 2015-06-09 by net-tobi

Let me know when I should test something again regarding the HTTP problem.

Posted at 2015-06-09 by @gfwilliams

There should be the status code instead of the HTTP version.

Yes, but that's probably a result of the newline at the start - I think the code that splits the HTTP response up got confused.

Do you think you could do a request with sim.at.debug() called, and attach the result so I can take a look at what gets sent and can then run it through the code here? Sorry, but it's a pain to do here without working hardware to try it on.

Posted at 2015-06-09 by net-tobi

Sure. Here is the output:

 _____                 _
|   __|___ ___ ___ _ _|_|___ ___
|   __|_ -| . |  _| | | |   | . |
|_____|___|  _|_| |___|_|_|_|___|
          |_| http://espruino.com
 1v79.19 Copyright 2015 G.Williams
>echo(0);
Connecting to sim900a module
["ATE0\r\n"
=undefined
] "A" <--- "A"
] "ATE0\r\n\r\nOK\r\n" <--- "TE0\r\n\r\nOK\r\n"
["AT+CPIN?\r\n"
] "\r" <--- "\r"
] "\n+CPIN: READY\r\n\r\nOK\r\n" <--- "\n+CPIN: READY\r\n\r\nOK\r\n"
["AT+CGATT?\r\n"
] "\r" <--- "\r"
] "\n+CGATT: 1\r\n\r\nOK\r\n" <--- "\n+CGATT: 1\r\n\r\nOK\r\n"
["AT+CIPSHUT\r\n"
] "\r" <--- "\r"
] "\nSHUT OK\r\n" <--- "\nSHUT OK\r\n"
["AT+CIPSTATUS\r\n"
] "\r" <--- "\r"
] "\nOK\r\n\r\nSTATE: IP INITIAL\r\n" <--- "\nOK\r\n\r\nSTATE: IP INITIAL\r\n"
["AT+CIPMUX=1\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
["AT+CIPHEAD=1\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
["AT+CSTT=\"pinternet.interkom.de\", \"\", \"\"\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
["AT+CIICR\r\n"
] "\r" <--- "\r"
] "\nOK\r\n" <--- "\nOK\r\n"
null
["AT+CIFSR\r\n"
] "\r" <--- "\r"
] "\n10.47.223.198\r\n" <--- "\n10.47.223.198\r\n"
IP:10.47.223.198
["AT+CIPSTART=0,\"TCP\",\"www.pur3.co.uk\",80\r\n"
] "\r\nOK\r\n" <--- "\r\nOK\r\n"
] "\r\n0, CONNE" <--- "\r\n0, CONNE"
] "0, CONNECT OK\r\n" <--- "CT OK\r\n"
["AT+CIPSEND=0,64\r\n"
] "\r\n> " <--- "\r\n> "
] "\r\n0" <--- "\r\n0"
] "0, SEND OK\r\n" <--- ", SEND OK\r\n"
["AT+CIPSEND=0,34\r\n"
] "\r\n> " <--- "\r\n> "
] "\r\n0, SEN" <--- "\r\n0, SEN"
] "0, SEND OK\r\n" <--- "D OK\r\n"
] "\r\n+RECEIVE" <--- "\r\n+RECEIVE"
] "+RECEIVE,0,289:\r\nHTTP/1.1 200 OK\r\nDate: Tue, 09 Jun 2015 11:07:06" <--- ",0,289:\r\nHTTP/1.1 200 OK\r\nDate: Tue, 09 Jun 2015 11:07:06"
] "+RECEIVE,0,239: GMT\r\nServer: Apache/2.2.14 (Ubuntu)\r\nLast-Modified: Fri, 15 Nov 2013 15:42:26 GMT" <--- " GMT\r\nServer: Apache/2.2.14 (Ubuntu)\r\nLast-Modified: Fri, 15 Nov 2013 15:42:26 GMT"
] "+RECEIVE,0,157:\r\nETag: \"c01036-d-4eb390b8a8d18\"\r\nAccept-Ranges: bytes\r\nContent-Length:" <--- "\r\nETag: \"c01036-d-4eb390b8a8d18\"\r\nAccept-Ranges: bytes\r\nContent-Length:"
] "+RECEIVE,0,86: 13\r\nVary: Accept-Encoding\r\nConnection: close\r\nContent-Type: text/plain\r\n\r\nHello World!\n" <--- " 13\r\nVary: Accept-Encoding\r\nConnection: close\r\nContent-Type: text/plain\r\n\r\nHello World!\n"
Response:  {
  "headers": {
    "Date": "Tue, 09 Jun 2015 11:07:06 GMT",
    "Server": "Apache/2.2.14 (Ubuntu)",
    "Last-Modified": "Fri, 15 Nov 2013 15:42:26 GMT",
    "ETag": "\"c01036-d-4eb390b8a8d18\"",
    "Accept-Ranges": "bytes",
    "Content-Length": "13",
    "Vary": "Accept-Encoding",
    "Connection": "close",
    "Content-Type": "text/plain"
   },
  "httpVersion": "P/1.1 200 OK\r\nDate: Tue, 09 Jun 2015 11:07:06 GMT\r\nServer: Apache/2.2.14 (Ubuntu)\r\nLast-Modified: Fri, 15 Nov 2013 15:42:26 GMT\r\nETag: \"c01036-d-4eb390b8a8d18\"\r\nAccept-Ranges: bytes\r\nContent-Length: 13\r\nVary: Accept-Encoding\r\nConnection: close\r\nContent-Type: text/plain\r\n\r\nHello World",
  "statusCode": "\nHTTP/1.1",
  "statusMessage": "200 OK\r\nDate: Tue, 09 Jun 2015 11:07:06 GMT\r\nServer: Apache/2.2.14 (Ubuntu)\r\nLast-Modified: Fri, 15 Nov 2013 15:42:26 GMT\r\nETag: \"c01036-d-4eb390b8a8d18\"\r\nAccept-Ranges: bytes\r\nContent-Length: 13\r\nVary: Accept-Encoding\r\nConnection: close\r\nContent-Type: text/plain\r\n\r\nHello World"
 }
--->Hello World
] "!\n\r\n" <--- "\r\n"
] "0, CLOSED\r\n" <--- "0, CLOSED\r\n"
>

Posted at 2015-06-09 by net-tobi

I can see there that the last character of the HTTP-Body as well is not parsed correctly. The correct string is "Hello World!"

Posted at 2015-06-09 by @gfwilliams

Ok, thanks! that's really handy. So it's actually not the GSM code at all, it's the SIM900 that's sending the extra newlines:

"\r\n+RECEIVE"
",0,289:\r\nHTTP/1.1 200 OK\r\nDate: Tue, 09 Jun 2015 11:07:06"
//      ^^^^

Now I can't find any info on +RECEIVE at all, so I don't know whether it's actually meant to do that after every RECEIVE or not... Maybe if you request a bigger file (>1.5kb?) we'll get two RECEIVEs, and can check... But for now let's assume that it always goes: +RECEIVE,X,Y:\r\n<data>

I've had to add a second handler called receiveHandler2, because unfortunately the newline after the +RECEIVE would totally confuse the AT handler if we left it in the buffer.

function receiveHandler(line) {
  var colon = line.indexOf(":\r\n");
  if (colon<0) return line; // not enough data here at the moment
  var parms = line.substring(9,colon).split(",");
  parms[1] = 0|parms[1];
  var len = line.length-(colon+3);
  if (len>=parms[1]) {
   // we have everything
   sockData[parms[0]] += line.substr(colon+1,parms[1]);
   return line.substr(colon+parms[1]+3); // return anything else
  } else { 
   // still some to get
   sockData[parms[0]] += line.substr(colon+3,len);
   return "+D,"+parms[0]+","+(parms[1]-len)+":"; // return +D so receiveHandler2 gets called next time    
  }
}

function receiveHandler2(line) {
  var colon = line.indexOf(":");
  if (colon<0) return line; // not enough data here at the moment
  var parms = line.substring(3,colon).split(",");
  parms[1] = 0|parms[1];
  var len = line.length-(colon+1);
  if (len>=parms[1]) {
   // we have everything
   sockData[parms[0]] += line.substr(colon+1,parms[1]);
   return line.substr(colon+parms[1]+1); // return anything else
  } else { 
   // still some to get
   sockData[parms[0]] += line.substr(colon+1,len);
   return "+D,"+parms[0]+","+(parms[1]-len)+":"; // return +D so receiveHandler2 gets called next time    
  }
}

// ....

exports.connect = function(usart, resetPin, connectedCallback) {
  rst = resetPin;
  gprsFuncs.at = at = require("AT").connect(usart);
  require("NetworkJS").create(netCallbacks);
  at.register("+RECEIVE", receiveHandler);
  at.register("+D", receiveHandler2);
  gprsFuncs.reset(connectedCallback);
  return gprsFuncs;
};

Posted at 2015-06-09 by net-tobi

That works!!!! Great! I tested it with small and big files and it seems to send that \r\n after each +RECEIVE

Thank you so much Gordon!

Posted at 2015-06-09 by net-tobi

This is the entire driver which is working for me. If you like you can publish it as official module.

Attachments:

sim900a.js

Posted at 2015-06-09 by @gfwilliams

Wow, great - thanks! Yes, I'll try and stick it online as a module.

Posted at 2015-06-15 by net-tobi

Hello Gordon,

I have a problem with the use of at.register('>') in the following code of the GPRS driver:

  send: function(sckt, data) {
    if (at.isBusy() || socks[sckt]=="Wait") return 0;
    if (!socks[sckt]) return -1; // error - close it
    var f = function(d) {
      at.unregister('>');
      if (d != sckt + ", SEND OK") return;
    };
    at.register('>', function() {
      at.write(data);
      return "";
    });
    at.cmd('AT+CIPSEND='+sckt+','+data.length+'\r\n', 10000, f);
    return data.length;
  }

How can it handle multiple sockets with it? In the AT lib I can just register for some chars once. The next call of the send function for another (or for the same) socket tries to register for '>' again or sends a new AT+CIPSEND without waiting for ">" which leads the communication to an inconsistent state. I tried to set the socket to "Wait" until ">" comes in for the particular socket, but requests for other sockets were still able to send.

In the ESP8266 driver the problem was not existing because you send the data directly after AT+CIPSEND, which is - unfortunately - not working with the SIM900.

Do you have an idea how to solve the problem?

Best,

Tobias

Posted at 2015-06-15 by DrAzzy

No, it is a problem on ESP8266 as well; the moment more than one connection is open at once, everything hits the fan.

Posted at 2015-06-16 by @gfwilliams

The ESP8266 problem is because of their stupid use of Linked/Unlinked with no connection number. The SIM900 shouldn't have that.

I guess the problem here is that at.isBusy() is reporting false because it's not actually busy, just waiting for >.

Why not add your own variable to track whether you're waiting or not?

send: function(sckt, data) {
    if (at.isBusy() || this.sendWaiting || socks[sckt]=="Wait") return 0;
    if (!socks[sckt]) return -1; // error - close it
    this.sendWaiting = true;
    var f = function(d) {
      at.unregister('>');
      this.sendWaiting = false;
      if (d != sckt + ", SEND OK") return; // <------- this doesn't seem to do anything?
    };
    at.register('>', function() {
      at.write(data);
      return "";
    });
    at.cmd('AT+CIPSEND='+sckt+','+data.length+'\r\n', 10000, f);
    return data.length;
  }

Posted at 2015-06-16 by net-tobi

Hello Gordon,

I tried to solve it like this yesterday night:

  /* Send data. Returns the number of bytes sent - 0 is ok.
  Less than 0  */
  send: function(sckt, data) {
    if (busy || at.isBusy() || socks[sckt]=="Wait") return 0;
    if (!socks[sckt]) return -1; // error - close it
    busy = true;
    at.register('>', function() {
      console.log('READY');
      at.unregister('>');
      at.write(data);
      return "";
    });
    at.registerLine(sckt + ', SEND OK', function() {
      at.unregisterLine(sckt + ', SEND OK');
      busy = false;
      return "";
    });
    at.cmd('AT+CIPSEND='+sckt+','+data.length+'\r\n');
    at.debug();
    return data.length;
  }
};

But for some reason I ran into a deadlock situation where busy was set to true but no SEND OK came in to remove it in some cases.

I will try your solution without waiting for SEND OK and give you a feedback.

Posted at 2015-06-16 by net-tobi

Okay we have to wait for SEND OK, otherwise data can be lost. My solutions from yesterday works now. I saw that the LOW_MEMORY flag was set during execution. I compressed the code now and it seems to work stable.

Here you find the current version of the driver.

Attachments:

sim900a_community.js

Posted at 2015-06-16 by @gfwilliams

It might be worth adding a timeout - Maybe just use the callback argument of at.cmd instead of the registerLine that you added? That includes a timeout if nothing is received in a given time period, so you should never be able to get in a deadlock.

Posted at 2015-06-16 by net-tobi

Please see the post above.

Okay, If I experience further problems with it, I will add a timeout.

Posted at 2015-06-16 by @gfwilliams

Thanks - I posted just a few secs after you, so didn't realise you'd sorted it out :)

Posted at 2015-06-16 by net-tobi

Hi Gordon... It is annoying... Again problems with GPRS. When the sim900 is ready for receiving data after AT+CIPSEND it sends:

] "\r\n> "

When I use the following code:

at.register('> ', function() {
  at.unregister('> ');
  at.write(data);
  return "";
});

It removes the "> " from the AT buffer but leaves "\r\n" in it which can cause problems for subsequent requests (maybe for the +RECEIVE handler as well). I tried as well to register for "\r\n> ". That didn't solve that for me. How would you handle that? There are as well situations like

] "\r" <--- "\r"
] "\n> " <--- "\n> "

or

["AT+CIPSEND=1,26\r\n"
] "\r\n>" <--- "\r\n>"
] "> " <--- " "

Posted at 2015-06-16 by net-tobi

maybe by extending the features of the AT lib?

Posted at 2015-06-16 by @gfwilliams

I'm not sure the issue is quite as simple as that. If you look at the AT module code responsible it would appear to be doing the right thing...

It looks to me like it copes with the cases where the line starts with \r or \n. But I'll do some tests and will let you know

Posted at 2015-06-16 by net-tobi

Yes this is as well part of the problem. My close handlers are not getting called if the line starts with \r\n or \r or \n. See here:

var handler = function(d) {
        var s;
        if(d === 'OK') {
          s = sckt;
          at.registerLine(s + ', CONNECT OK', function() {
            at.unregister(s + ', CONNECT OK');
            socks[s] = true;
          });
          at.registerLine(s + ', CLOSED', function() {
            at.unregisterLine(s + ', CLOSED');
            socks[s] = undefined;
          });
        }
      }; 
      at.cmd('AT+CIPSTART='+sckt+',"TCP",'+JSON.stringify(host)+','+port+'\r\n', 10000, handler);

This unfortunately happens sometimes, for example a few seconds ago I had the situation:

] "\r\n1, CLOSED\r\n" <--- "\r\n1, CLOSED\r\n"

The close handler has not been called here :(

0 replies

espruino-discuss3 · 2025-02-12T14:33:16Z

espruino-discuss3
Feb 12, 2025
Maintainer Author

Posted at 2015-06-16 by @gfwilliams

Ok, well you can test in a controlled manner using the Loopback like this:

var at = require("AT").connect(LoopbackA);
at.registerLine('1, CLOSED', function() {
  console.log("I got called");
});
at.debug();

LoopbackB.write("\r\n1, CLOSED\r\n");

Now that actually works, so I think you have some other problem there.

However the following doesn't:

var at = require("AT").connect(LoopbackA);
at.register("> ", function(x) {
  console.log("HANDLER: "+JSON.stringify(x));
  return "";
});
at.debug();

LoopbackB.write("\r");
setTimeout(function() {
  LoopbackB.write("\n> ");
},100);

That was an issue with the AT module, which I've just updated and fixed.

But your other issue ("\r\n>" then " ") was actually the same as the one that was stopping ">" from working a week ago. It should be fixed if you're using an up to date build from GitHub (I fixed it last week), but I guess yours might be older?

If you want to fix it on the existing firmware, you just need to register a handler for ">" without the space. Then you handle the check for the space yourself:

var at = require("AT").connect(LoopbackA);
at.register(">", function(x) {
  if (x.substr(0,2)=="> ") {
    console.log("HANDLER: "+JSON.stringify(x));
    return "";
  } else return x;
});
at.debug();

LoopbackB.write("\r\n>");
setTimeout(function() {
  LoopbackB.write(" ");
},100);

Posted at 2015-06-16 by net-tobi

The new AT lib did it! Thank you so much Gordon! It works much more stable now. I'll test it tomorrow intensively.

Posted at 2015-06-18 by net-tobi

It is working well without any changes being necessary in the driver I uploaded here a few days ago. So you can use it as module. As well if someone else needs help regarding the SIM900 hardware I will of course help to get it running.

Posted at 2015-06-18 by @gfwilliams

That's great, thanks! I plan to come up with a page on the Espruino website for it soon!

Posted at 2015-06-18 by net-tobi

@gfwilliams : I have to say thank you for the great support!

Posted at 2015-06-18 by @gfwilliams

No problem - glad you got it working - and thanks for getting stuck in and actually making the module in the first place!

It's something I should have done myself, but I now have 2 GSM modules, neither of which seem to be able to get a signal!

Posted at 2016-06-15 by bmckay

Hey Guys - I'm new to IoT but am working on a project that needs to connect to cellular data as it will be a mobile type device. Did this thread end up with the ability to use GPRS data using the SIM900 hardware?

Thanks for helping a n00b get his feet wet!

Posted at 2016-06-16 by @gfwilliams

Yes, absolutely! There's a page with some information on how to do it here: http://www.espruino.com/SIM900

It's pretty easy - you just need to ensure the GSM module has a good power supply, and that you know your mobile carrier's access point details (it's easy enough to google).

If you've got other questions it might be better to post up in a new thread though - this one's getting a bit long!

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