Implement reading from the serial port. Better error checking

[elafargue]

This PR implement reading from the serial port. This is a simple (unique) callback driven mechanism, so the javascript app will have to continuously re-poll the serial port after getting data or a timeout (buffer with length = 0). A better mechanism would be to trigger "onData" events.

Also, added more checks on the state of the serial port, so that in case a Cordova app attempts read/write/close operations on ports that were not previously opened, the app does not crash but calls the error callback.

[xseignard]

So I merged and tried your code, but I can't read from the Arduino.
Do you have some simple snippet I can test against?

Regards,

Xavier

[elafargue]

Hello Xavier - je pense qu'on peut parler français :)

J'ai uniquement testé avec un FTDI jusqu'ici, voici le code que
j'utilise:

• Ouverture du port d'abord
• Callback "onOpen": serial.read(onRead)
• Callback onRead : pour mon utilisation, je fais un split sur ";", si tu veux lire ligne par ligne, fais un split sur '\n' ou '\r'...

function onRead(readInfo) {
// readInfo is an ArrayBuffer
if (readInfo.byteLength == 0) {
// Delay next attempt to read in order to avoid a fast loop
setTimeout(function() {
serial.read(onRead);
}, 100);
return;
}
// Inspired by Node's serialport library, why reinvent the wheel:
data += ab2str(readInfo);
// Split collected data by delimiter
var parts = data.split(';')
data = parts.pop();
parts.forEach(function (part, i, array) {
serialEvent(part);
});
// Keep on reading.
serial.read(onRead);
};

Hoping this helps! Very stable for me, I tested this yesterday for more
than 30 minutes of intense serial exchanges without any issue,

Ed

On Sun, Mar 23, 2014 at 10:09 AM, Xavier Seignard
[email protected]:

So I merged and tried your code, but I can't read from the Arduino.
Do you have some simple snippet I can test against?

Regards,

Xavier

Reply to this email directly or view it on GitHubhttps://github.com//pull/3#issuecomment-38388623
.

[xseignard]

Salut,

I found my problem, it doesn't work with my Arduino Leonardo, but I tested with an Arduino Pro Mini and it works, weird.

Here is the snippet I used

var data;
var paragraph = document.getElementById('test');
var ab2str = function(buf) {
    return String.fromCharCode.apply(null, new Uint8Array(buf));
};
var errorCallback = function(message) {
    alert('Error: ' + message);
};
var onRead = function (readInfo) {
    // readInfo is an ArrayBuffer
    if (readInfo.byteLength == 0) {
        console.log('no data');
        // Delay next attempt to read in order to avoid a fast loop
        setTimeout(function() {
            serial.read(onRead);
        }, 100);
        return;
    }
    // Inspired by Node's serialport library, why reinvent the wheel:
    data += ab2str(readInfo);
    var parts = data.split('\n');
    data = parts.pop();
    console.log(data);
    paragraph.textContent = data;
    // Keep on reading.
    serial.read(onRead);
};

serial.requestPermission(
    function(successMessage) {
        serial.open(
            {baudRate: 9600},
            function(successMessage) {
                serial.read(onRead);
            },
            errorCallback
        );
    },
    errorCallback
);

Merci de ton aide!

a+

[elafargue]

Perfect ! Glad it worked for you too.

I'm using your plugin for a custom amateur radio transceiver controller,
I might release it publicly one of these days, but ironically, my visa
status in the US makes it difficult to do, because I am only allowed to
work for my current employer, and this is done outside of them...

Ed

On Sun, Mar 23, 2014 at 12:07 PM, Xavier Seignard
[email protected]:

Salut,

I found my problem, it doesn't work with my Arduino Leonardo, but I tested
with an Arduino Pro Mini and it works, weird.

Here is the snippet I used

var data;
var paragraph = document.getElementById('test');
var ab2str = function(buf) {
return String.fromCharCode.apply(null, new Uint8Array(buf));
};
var errorCallback = function(message) {
alert('Error: ' + message);
};
var onRead = function (readInfo) {
// readInfo is an ArrayBuffer
if (readInfo.byteLength == 0) {
console.log('no data');
// Delay next attempt to read in order to avoid a fast loop
setTimeout(function() {
serial.read(onRead);
}, 100);
return;
}
// Inspired by Node's serialport library, why reinvent the wheel:
data += ab2str(readInfo);
var parts = data.split('\n');
data = parts.pop();
console.log(data);
paragraph.textContent = data;
// Keep on reading.
serial.read(onRead);
};

serial.requestPermission(
function(successMessage) {
serial.open(
{baudRate: 9600},
function(successMessage) {
serial.read(onRead);
},
errorCallback
);
},
errorCallback
);

Merci de ton aide!

a+

Reply to this email directly or view it on GitHubhttps://github.com//pull/3#issuecomment-38393402
.

[xseignard]

Even if it is open source?

Btw, I still have some troubles with the decoding of the ArrayBuffer, I get some unreadable characters, I don't know if it comes from the cheap usb/serial converter I use, or from the way I translate the buffer to a string, hre is what I do:

var ab2str = function(buf) {
    return String.fromCharCode.apply(null, new Uint8Array(buf));
};

What's your technique? I tried to search on the source of node-serialport, but with no luck.

And how do you send data from your device to Android?

In Arduino I do a simple thing like this:

void setup() {
  Serial.begin(9600);
}

void loop() {
  int sensorValue = analogRead(A0);
  Serial.println(sensorValue);
}

Any idea?

Regards,

Xavier

[elafargue]

Open Source might be an option, but then I will get hate mail from quite
a few people who are selling the same sort of apps as their main activity -
or selling online services, what I did is close to www.remotehamradio.com,
only nicer ;-) Anyway, I'll work it out eventually, no worries.

Here is what I do in my code: same ab2str technique as yours, no issue
with undreadable characters.

My device is a Ham radio (elecraft KX3, look it up), which sends data on
the serial port using a fairly straightforward ASCII protocol - with a bit
of binary here and there. I have not tried with Arduinos yet, will come
later I guess!

Ed

On Sun, Mar 23, 2014 at 3:00 PM, Xavier Seignard
[email protected]:

Even if it is open source?

Btw, I still have some troubles with the decoding of the ArrayBuffer, I
get some unreadable characters, I don't know if it comes from the cheap
usb/serial converter I use, or from the way I translate the buffer to a
string, hre is what I do:

var ab2str = function(buf) {
return String.fromCharCode.apply(null, new Uint8Array(buf));
};

What's your technique? I tried to search on the source of node-serialport,
but with no luck.

And how do you send data from your device to Android?

In Arduino I do a simple thing like this:

void setup() {
Serial.begin(9600);
}

void loop() {
int sensorValue = analogRead(A0);
Serial.println(sensorValue);
}

Any idea?

Regards,

Xavier

Reply to this email directly or view it on GitHubhttps://github.com//pull/3#issuecomment-38398942
.