Not long ago, I wrote a post regarding hardware and software interfacing a Maxim DS1620 Digital Thermometer/Thermostat. In my copious free time, I decided to follow through with a working example that displays temperature data on any LCD display that uses the ubiquitous Hitachi 44780 chipset. Below you’ll find a schematic as well as a link to download the MPASM and GPUtils-compatible source assembler code. This example uses the same Microchip PIC16F690 microcontroller 8-bit parallel control with the LCD module. The module that I’m using is an Eone 1602a that I salvaged from a hobby charger.
The schematic is simple and doesn’t display open pins tied to ground, etc but it will run either way. Be a good EE though and don’t leave these dangling. 🙂
The project displays temperatures in degrees C only, I haven’t taken the time to implement a C to F conversion computationally or via lookup table, but I’ll probably implement this when I have some down-time. Feel free to offer suggestions as to how this should be done, I was going to use a lookup table.
I hope you find this example useful. Leave a comment if you’d like to critique my work and offer suggestions or if you have any questions.
The full source code zip can be downloaded here.