Articles March 17, 2013

Some Debug Required

First test of Twitter updates getting written to the Arduino from Ruby didn't go quite right as seen from the video below, some debugging required.

Testing writing the same message from the Arduino IDE gives the same results so looks like problem is in the Arduino code. Maybe the message is too long for the LCD's buffer?

The Twitter to Serial port Ruby script can be found at https://github.com/alastairhm/arduino/tree/master/SerialMessage

Doodle's Geek Monkey by Alastair Montgomery

Articles March 14, 2013

Ruby Script to get Twitter mentions

Here is a short Ruby script to check for mentions on Twitter, it uses the Twitter Gem.

Plan to use this to send messages to my Arduino, looking for a good Ruby Serial Port Gem now.

# Find your Twitter Mentions
require “rubygems”
require “twitter” #https://github.com/sferik/twitter for config details
require “pp”
prevID = 0
while true
latestMention = Twitter.mentions(:count => 1)[0]
if prevID != latestMention.id
msg = latestMention.user.screen_name + " " + latestMention.text
#puts msg.size
puts msg
prevID = latestMention.id
else
puts “No new updates”
end
sleep 60
end

Articles March 14, 2013

Sending Arduino messages over serial port

Note: 1 of this post’s 6 links are now broken — mostly dead 2008–2013 feed-syndication infrastructure (FeedBurner, Gawker, AOL’s old blog network, Pheedo, Yahoo Pipes). Left as originally published.

Video of sending a message to the Arduino over the serial port which then gets scrolled on a SainSmart LCD shield.

Idea was to use it to display tweets, just need to write the Ruby code to get the tweet and send it over the serial port now.

Here is the first version of the sketch uploaded to the Arduino.
All code can be found at https://github.com/alastairhm/arduino.git

// Auto scroll a message on the LCD and receive new messages via Serial port. // Alastair Montgomery (c) 2013 // Version 1.00 // include the library code: #include <LiquidCrystal.h> #include <string.h>

// initialize the library with the numbers of the interface pins // below for SainSmart LCD Shield LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

Articles March 6, 2013

Sainsmart LCD Shield Test

Testing my Sainsmart LCD Shield.

/* LiquidCrystal Library - Hello World Demonstrates the use a 16x2 LCD display. The LiquidCrystal library works with all LCD displays that are compatible with the Hitachi HD44780 driver. There are many of them out there, and you can usually tell them by the 16-pin interface. This sketch prints "Hello World!" to the LCD and shows the time. The circuit: * LCD RS pin to digital pin 12 * LCD Enable pin to digital pin 11 * LCD D4 pin to digital pin 5 * LCD D5 pin to digital pin 4 * LCD D6 pin to digital pin 3 * LCD D7 pin to digital pin 2 * LCD R/W pin to ground * 10K resistor: * ends to +5V and ground * wiper to LCD VO pin (pin 3) Library originally added 18 Apr 2008 by David A. Mellis library modified 5 Jul 2009 by Limor Fried (http://www.ladyada.net) example added 9 Jul 2009 by Tom Igoe modified 22 Nov 2010 by Tom Igoe This example code is in the public domain.

http://www.arduino.cc/en/Tutorial/LiquidCrystal */

// include the library code: #include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins //LiquidCrystal lcd(12, 11, 5, 4, 3, 2); LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

Articles February 8, 2013

Creating a Ruby/ Sinatra dev environment

Note: 1 of this post’s 8 links are now broken — mostly dead 2008–2013 feed-syndication infrastructure (FeedBurner, Gawker, AOL’s old blog network, Pheedo, Yahoo Pipes). Left as originally published.

To work my way through the book Cloning Internet Applications with Ruby I've created a development environment using Vagrant and Puppet.

You will need the following installed;

VirtualBox VM https://www.virtualbox.org/
Vagrant http://www.vagrantup.com/

These pages are also helpful
http://net.tutsplus.com/tutorials/php/vagrant-what-why-and-how/
http://titusd.co.uk/2010/04/07/a-beginners-sinatra-tutorial/

You can see my setup files at https://github.com/alastairhm/vagrant.git

Doodle's Geek Monkey by Alastair Montgomery

Articles January 5, 2013

LCD shield

Latest toy for my Arduino, now what to use it for?

Articles December 6, 2012

Arduino Code on Github

I've started uploading my Arduino examples code to Github
https://github.com/alastairhm/arduino

Doodle's Geek Monkey by Alastair Montgomery

Articles December 3, 2012

Dusting off the iron

My first attempt at soldering after around eight years away from the soldering iron.

Articles November 25, 2012

Counting up to 1023

Decided in the end to wire up all 10 LEDS in the LED bar graph.
Using the sketch below get the results shown in the video.

int numLed = 10;
int ledpins[] = {
  13,12,11,10,9,8,7,6,5,4};
int mask[] = {
  1,2,4,8,16,32,64,128,256,512};
int counter = 0;
void setup() {             

  // initialize the digital pin as an output.
  for (int i=0;i<numLed;i++){
    pinMode(ledpins[i], OUTPUT);
    digitalWrite(ledpins[i], HIGH);
    delay(250);
  }
}

Articles November 23, 2012

Arduino Binary second counter

Next step with my Arduino is to set up a binary second counter.
Basic using the LED Bar Graph or six single LEDs to count seconds in binary

/*
Binary Second Counter
 
 Created Alastair Montgomery 22/11/2012
 
 */
int ledPins[] = {
  7,8,9,10,11,12};
int mask[] = {
  1,2,4,8,16,32};
int ledCount = 6;
void setup() {
  for (int thisPin =0; thisPin < ledCount; thisPin++) {
    pinMode(ledPins[thisPin], OUTPUT);
  }
}