CMUcam5 Pixy

The Pixy is a computer vision camera that does all the hard work on-board. It can recognize coloured objects that it 'sees', and will then report their size and position back to a connected microcontroller.

The official documentation is here: [http://cmucam.org/projects/cmucam5/wiki/Quick_Start]

There's an Espruino module called Pixy (About Modules) which will interface to it.

Wiring Up

Use SPI (the default for Pixy), and connect as follows:

CMUCam		Espruino
1	SPI MISO	B14
2	5V	Bat
3	SPI SCK	B13
4	SPI MOSI	B15
5	I2C SCL
6	GND	GND
7	SPI SS
8	GND
9	I2C SDA
10	GND

Note: Pins 7 to 10 are not exposed on the ribbon cable that comes with the pixy.

Software

SPI2.setup({sck : B13, miso : B14, mosi : B15, baud : 1000000});
var pixy = require("Pixy").connect(SPI2);
console.log(pixy.getBlocks());

returns something like:

[
  {"id":1,"x":18,"y":24,"width":17,"height":2}
]

Note: There may currently be issues with the minified version of this module. To use the unminified version, change .min.js|.js to .js|.min.js in the Web IDE's settings menu.

Reference

// For internal use - get a work and send out any queued up data
Pixy.prototype.getWord = function () { ... }

// For internal use - get a single byte
Pixy.prototype.getByte = function () { ... }

// For internal use - queue the given data to be sent
Pixy.prototype.send = function (data) { ... }

// For internal use - get the start of a frame
Pixy.prototype.getStart = function () { ... }

/* Get an array of tracked blocks in the form:

  { id: number, x: number, y: number, width: number, height: number }
*/
Pixy.prototype.getBlocks = function () { ... }

// Return a new Pixy object that's connected to the given SPI port
exports.connect = function (spi) { ... }

Using

(No tutorials are available yet)

Buying

• Order from Charmed Labs
• digitalmeans.co.uk