Here’s a (I think) accurate diagram of the circuit:
You may click on the image above to load the .pdf version.
Digital I/O pins 2, 7-10 and 12 are used to control the LCD display, and pins 3 and 4 are used to control the rangefinder. The LCD has a variable resistor on pin 4 that controls the contrast.
The LCD interfacing design was based off the information on the Arduino LCD Library Page
However, I eventually used the 4-bit Arduino LCD Library, as it frees up more pins on the board.
Stripboard Design
The circuitboard is little more than a bit of stripboard with some headers on to slot into the arduino prototyping board, and to plug into the LCD panel and sensor.
I designed it using the free version of a neat little program called VeeCad, which is especially designed for creating stripboard layouts.
Error in the layout
There is an error in the layout. I had thought that a gap would be needed between pins 7 and 8 on the arduino, but this turned out not to be the case. However, bending the pins on the plug-in cicuit allows it to still interface with the arduino with little trouble.
June 7th, 2008 at 1:08 pm ()
