Stoyan Zhekov zh

I turned my Raspberry Pi into a robot, controlled by a Wii nunchuk. It's surprisingly easy to do - at least, surprisingly to me, who has not previously made a robot. But because it's surprising, it might help others to have a guide, so here one is.

Parts

I'm linking to SKPang for most of these, but Sparkfun and Adafruit would be good places to look if you're in the US.

(If you're in the UK, a word of caution - I bought motors and some other stuff from Sparkfun to save £7 over SKPang, but the package got stopped at customs and I had to pay £4 VAT and £8 handling fees. My understanding is that this will only happen on packages whose contents are worth more than £15, but you'd be a fool to trust me on this. It didn't happen when I spent £20 at Adafruit or £5 at Sparkfun. YMMV.)

Raspberry Pi - for the robot logic. An Arduino or similar could be substituted (though the software would need to be rewritten).

Introduction

The MCP23017 is an I/O expander chip. It has 16 GPIO pins which you can control using an I2C interface using two pins from a Raspberry Pi, plus a power source and sink (which can also come from the Pi). It's not quite as simple as directly controlling the Pi's GPIO pins, but it's not complicated, either.

You need to install i2c-tools, which is probably in your distribution's package manager. You also need a kernel with I2C support; you might need to modprobe i2c-dev. It would presumably be possible to do without either of these things, and bitbang the I2C protocol over GPIO, but I don't understand the protocol well enough to try.

On pin numbering: if you like, you can refer to the datasheet for the MCP23017. There's a small dot in one corner of the chip, with a semi-circular cut-out at that end. The pin near

Setting up and installing rbenv, ruby-build, rubies, rbenv-gemset, and bundler

This guide enables you to install (ruby-build) and use (rbenv) multiple versions of ruby, isolate project gems (gemsets and/or bundler), and automatically use appropriate combinations of rubies and gems.

TL;DR Demo

# Ensure system is in ship-shape.

aptitude install git zsh libssl-dev zlib1g-dev libreadline-dev libyaml-dev

	var gpio = require("gpio")
	var gpio22, intervalTimer

	// Flashing lights if LED connected to GPIO22
	gpio22 = gpio.export(22, {
	ready: blinkLED
	})

	function blinkLED() {
	intervalTimer = setInterval(function() {

	var serialport = require('node-serialport')

	var sp = new serialport.SerialPort("/dev/ttyO3", {
	parser: serialport.parsers.raw,
	baud: 9600
	})

	sp.on('data', function(chunk) {
	console.log(chunk.toString('hex'), chunk.toString(), chunk)
	})

	{_} = require 'underscore'
	child_process = require 'child_process'
	async = require 'async'

	healthCheckInterval = 60 * 1000
	bounceInterval = 60 * 1000
	bounceWait = bounceInterval + 30 * 1000

	delayTimeout = (ms, func) -> setTimeout func, ms
	class MonitoredChild

	#!/usr/bin/env python
	# encoding: utf-8
	"""
	movie_recommender.py

	Created by Thomas Cabrol on 2012-04-06.
	Copyright (c) 2012 __MyCompanyName__. All rights reserved.
	"""

	import csv

	#!/usr/bin/env sh

	##
	# This is script with usefull tips taken from:
	# https://github.com/mathiasbynens/dotfiles/blob/master/.osx
	#
	# install it:
	# curl -sL https://raw.github.com/gist/2108403/hack.sh \| sh
	#

	#!/usr/bin/env ruby

	# This is a basic deploy script for Heroku apps.
	# It provides a structure you can use to expand on
	# and add your own prereqs and deploy tasks.
	#
	# It basically ensures that:
	# 1. There are no uncommited files
	# 2. You can ssh to github
	# 3. You can connect to heroku

	source "https://rubygems.org"

	gem 'sprockets'
	gem 'sprockets-sass'
	gem 'sass'
	gem 'compass'
	gem 'bootstrap-sass'
	gem 'handlebars_assets'
	gem 'coffee-script'