Still playing with my new toy, the Arduino Mega, this time with an character LCD with a parallel interface. The LCD I had laying around but you can buy them pretty much anywhere at low cost. I used this guide for info on how to wire it up and how to use the Arduino 4bit LCD library to display text.
Also of interest was this website which gives you the simple code to make any custom ‘character’ to display on the LCD. If you take the time you can even even join multiple custom characters together to make simple images like the dog below.
It should even be possible to animate the dog by moving it one frame at a time, if only I had the patiences that is..
Of course the LCD can also be used for more practical purposes, such as displaying information about a reprap heated print bed. A good example and guide is can be found at Arcol’s blog. Also more info on the reprap wiki. I plan on eventually making something very similar but with a few modifications of my own.
These modifications include displaying on the LCD the current bed temperature, the temperature the bed is set to reach and the cool down rate for after a print, in degrees per minute. I would also like to include a few tact switches for adjusting up and down bed temperatures and the cool down rate on the fly.
Lastly, a flashing custom character could also be displayed next to the bed temperature to indicate if a secondary high power quick warm up element was active as controlled by a mechanical relay. This character would not be displayed on the LCD once the bed is up to temperature and a lower power, transistor controlled element takes over. As the Mega has 54 digital I/O pins I’m fairly sure it can spare the 13 or so needed to run the LCD, temperature adjustment switches, and relays/power transistors etc.
An example of how this might look is shown below.
This is all some way off from being constructed which gives me plenty of time to continue to get acquainted with the Arduino code so that there may actually be a small chance of bringing these idea into reality.