T2 Issues

[reconbot]

I'm not sure if these are the tessel issues or tessel-button issues, but lets figure that out!

var tessel = require('tessel');
var Button = require('tessel-gpio-button');

var buttonPin = tessel.port.A.pin[0];
var button = Button.use(buttonPin);
var led = tessel.port.B.pin[0];

led.output(0);

button.on('press', function(){
  led.output(1);
});

button.on('release', function(){
  led.output(0);
});

buttonPin is set to A0 and I get this error

INFO Running led-test.js...
/usr/lib/node/tessel-export.js:437
      throw new Error('Interrupts are not supported on pin ' + this.pin);
            ^
Error: Interrupts are not supported on pin 0
    at Tessel.Pin.addListener (/usr/lib/node/tessel-export.js:437:13)
    at new Button (/tmp/remote-script/node_modules/tessel-gpio-button/index.js:17:17)
    at Object.use (/tmp/remote-script/node_modules/tessel-gpio-button/index.js:67:10)
    at Object.<anonymous> (/tmp/remote-script/led-test.js:5:21)
    at Module._compile (module.js:426:26)
    at Object.Module._extensions..js (module.js:444:10)
    at Module.load (module.js:351:32)
    at Function.Module._load (module.js:306:12)
    at Function.Module.runMain (module.js:467:10)
    at startup (node.js:117:18)

The hardware pin mapping doesn't say pin 0 is any different other than that it's pulled up, that's unfortunate.

Alright lets try again with pin A2, since that should be like any other.

/usr/lib/node/tessel-export.js:446
        throw new Error('Cannot set pin interrupt mode to ' + mode +
              ^
Error: Cannot set pin interrupt mode to rise; already listening for fall
    at Tessel.Pin.addListener (/usr/lib/node/tessel-export.js:446:15)
    at new Button (/tmp/remote-script/node_modules/tessel-gpio-button/index.js:21:17)
    at Object.use (/tmp/remote-script/node_modules/tessel-gpio-button/index.js:67:10)
    at Object.<anonymous> (/tmp/remote-script/led-test.js:5:21)
    at Module._compile (module.js:426:26)
    at Object.Module._extensions..js (module.js:444:10)
    at Module.load (module.js:351:32)
    at Function.Module._load (module.js:306:12)
    at Function.Module.runMain (module.js:467:10)
    at startup (node.js:117:18)

What? I can confirm that again when I try to run something like this directly on the t2's repl.

var tessel = require('tessel');
var buttonPin = tessel.port.A.pin[2];
buttonPin.on('fall', console.log);
buttonPin.on('rise', console.log);

I get the same error.

[reconbot]

Ahh, this is being tracked on tessel/hardware-modules#5

[dudleyjosh]

There are actually two issues related to using this for T2.

1. Only pins 2, 5, 6 & 7 allow interrupts on the T2 and you can only add one event per pin (so rise/fall events have to become a single change event.

2. The pin.read() function works differently between T1 & T2. T1 would allow a callback in the form of:

pin.read(function(value){});

Where as T2 expects:

pin.read(function(err, value){});

It may not be the best solution, but I got the following to work for both T1 & T2:

// Begin listening for events
  /*
  self.hardware.on('fall', function () {
    self._press();
  });

  self.hardware.on('rise', function () {
    self._release();
  });
  */
  self.hardware.on('change', function() {
    self.hardware.read(function(err, value) {
      if ( err && (err != 0 && err != 1) ) {
        console.log(err);
      }
      else if ( err == 0 || value == 0 ) {
        self._press();
      }
      else {
        self._release();
      }
    });
  });

  // Make sure the events get emitted, even if late
  setInterval(function () {
    /*
     if(!self.hardware.read()) {
     self._press();
     } else {
     self._release();
     }
     */
    self.hardware.read(function(err, value) {
      if ( err && (err != 0 && err != 1) ) {
        console.log(err);
      }
      else if ( err == 0 || value == 0 ) {
        self._press();
      }
      else {
        self._release();
      }
    });
  }, self.delay);

[tyler-g]

@dudleyjosh thanks for this. I have the tessel2 and that change made this library work. Yes you're right the difference is in how the 1 and 2 interpret the .read method. Tessel2 passes error and then value whereas Tessel1 just passes value.

[dudleyjosh]

@tyler-g FYI, I am working on PR-168 to make the T2 allow both a rise and fall event simultaneously again which will allow this button code to work exactly the way it was originally... with the exception of the one .read() which will have to be addressed per the example above.

[tyler-g]

@dudleyjosh 👍 , glad to help if needed