Minimal 3x5 numeric font on a LCD Matrix for Arduino Nano.

Doodle’s Geek Monkey by Alastair Montgomery

Testing a LCD Max7219 Matrix with an Arduino Nano, thank to http://tronixstuff.com/2013/10/11/tutorial-arduino-max7219-led-display-driver-ic/

#include <LedControl.h>
LedControl lc=LedControl(12,11,10,1);
// pin 12 is connected to the MAX7219 pin 1
// pin 11 is connected to the CLK pin 13
// pin 10 is connected to LOAD pin 12
// 1 as we are only using 1 MAX7219
void setup(){
  lc.shutdown(0,false);
  lc.setIntensity(0,8);
  lc.clearDisplay(0);
}
        

Been trying out 123D Circuits an GITHUB style online circuit designer and simulator.

Doodle’s Geek Monkey by Alastair Montgomery

Short script to send Twitter mention messages to a serial port using Ruby and the gems twitter and serialport.

# Find your Twitter Mentions and send them to Arduino on Serial Port
require “rubygems”
require “twitter” #https://github.com/sferik/twitter for config details
require “serialport” #http://rubygems.org/gems/serialport
require “pp”
prevID = 0
puts “Setting Up Serial Port”
myport = SerialPort.new("/dev/ttyACM0",“9600”.to_i)
sleep(10)
while true
puts “Checking for mentions”
latestMention = Twitter.mentions(:count => 1)[0]
if prevID != latestMention.id
msg = latestMention.user.screen_name + " " + latestMention.text
puts “-” + msg
bytes = myport.write(msg)
puts “-” + bytes.to_s
prevID = latestMention.id
else
puts “-No new updates”
end
sleep 60
end
myport.close

Doodle’s Geek Monkey by Alastair Montgomery

Got my Arduino LCD message scroller working last night, will post a video later when I do an end to end test with my Twitter mentions.

Here is the code (also at GitHub 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 1.02
 
// 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);
        

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

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);
        

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);
        

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

Doodle's Geek Monkey by Alastair Montgomery

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);
  }
}
        

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);
  }
}