i2c-1 pins not exposed on PocketCHIP

[bbx10]

The pocketCHIP exposes the i2c-2 pins but not i2c-1 so changing the default to i2c-2 would it possible to use J5 i2c on the pocketCHIP.

Also /dev/i2c-1 is not available on Headless 4.4.

chip@chip44:~$ ls -l /dev/i2c*
crw-rw---- 1 root i2c 89, 0 Jul 19 07:17 /dev/i2c-0
crw-rw---- 1 root i2c 89, 2 Jul 19 07:17 /dev/i2c-2

Changing chip-io.js to use /dev/i2c-2 works OK for HTU21D and BMP180 i2c sensors.

  var i2c = new I2C(2, address);
  var i2c = new I2C(2, address);

[sandeepmistry]

Hi @bbx10,

Thanks for the heads up on this, could you please submit pull request for this change? I'll release v2.0 later this week.

[bbx10]

@sandeepmistry

Oops, please hold on this change. I am getting garbled results now but it was working last night. I hope I have not fried my sensor boards.

[bbx10]

I found the bmp180 produces wildly varying results even when used on CHIP GUI 4.3 and i2c-1. The bmp180 fails in the same way on GUI 4.3 i2c-2 and Headless 4.4 i2c-2.

The htu21d produces correct temperature values in all 3 cases above. The humidity part of the sensor may be damaged because it works only sometimes. I do not currently see a pattern to the failure.

My conclusion: Changing from bus 1 to 2 is OK.

[ugate]

@bbx10 I'm going to runs some tests using a PCA9685 over i2c using i2c-2 on v4.4. I'll report back the results here. I've also reviewed the johnny-five API and found that we should be adding/updating the bus number via options passed into five class derivatives like Servo constructors. I've verified that any options passed into classes like Servo are passed into Board.i2cConfig as an object (not milliseconds as the docs indicate- see below) using the current stable release of johnny-five. I'll submit a pull request once I have tested the fix for this thoroughly.

This will allow us to do things like:

var chipio = require('chip-io');
var board = new five.Board({
  io: new chipio(),
  timeout: 9999999
});
board.on("ready", function() {
  console.log("Connected");
  // Initialize the servo instance
  var a = new five.Servo({
    address: 0x40,
    controller: "PCA9685",
    pin: 0,
    bus: 2 // define chip-io i2c bus here
  });
  var b = new five.Servo({
    address: 0x40,
    controller: "PCA9685",
    range: [0, 180],
    pin: 1,
    bus: 2 // define chip-io i2c bus here
  });
  var degrees = 0;
  a.to(degrees);
  b.to(degrees);
});

[sandeepmistry]

PR #10 from @bbx10 fixes this. Also #12 from @rwaldron will use the bus passed into i2cConfig, and defaults to bus 2.

I'll update the read me accordingly.