This is one of many projects I have been playing around with. This is one of Atmel’s ATmega644-20PU connected to an ELECTRONIC ASSEMBLY’s DOGM128S-6 graphical LCD display complete with the blue backlight.
This video shows how the whole thing works together.
First off the display mounting, I had to figure out a way to mount the LCD and backlight while making it easy to prototype with.
This produced a nice layout with a clean look and no jumper wires. 🙂
This close-up shows a bitmap I make in Photoshop being displayed with many random circles being drawn in the background, this was initially to test my circle algorithm, but after I noticed they looked like water reflections I left them.
This is the brains of the operation, it is an ATmega644 running at 20MHz thanks to the large crystal and load capacitors. The smaller crystal above is a 32.768 KHz RTC (Real Time Clock) crystal; the Atmega’s 8-bit Timer/Counter2 is designed just for this and doesn’t even need load capacitors. The Timer/Counter2’s prescaler is set to 128 and the overflow interrupt is then set up to call a small bit of code that increments the seconds and adjust all the other variables accordingly 32,768Hz / 128 / 256 (8-bit) = 1Hz; presto an interrupt that occurs every one second it’s magic 🙂
And finally the buttons to interact with the display, these are currently used to set the date and time, but they could be used for much more.
- Parts used on this Project
- DOGM Graphic Modules FSTN(-) Transmissive Black Background
- Fitting LED Backlights Blue LED Backlight For DOG-M Series
- Monolithic Radial Lead Capacitors 1uF 16volts Y5V +80-20% 5.0mm L/S
- Voltage Regulators 3.3V 0.1A Positive
- Regulators – Voltage 3-Terminal Fixed Positive
- Radial Aluminum Electrolytic Capacitors – 85 Degree 33UF 25V
- Radial Aluminum Electrolytic Capacitors – 85 Degree 100uF 6.3V 5×11
- HC49/US MHz Range Metal Can Crystals +/-20ppm 20MHZ FUNDAMENTAL
- Ceramic Disc Capacitors 50V 22pF NPO 5% Tol