Now it’s time to try two of the ultrasonic rangers together and verify that I can use ethernet cable to connect them. I want to be able to use ethernet cable for several reasons:
- Cheap
- Practically ubiquitous
- Easy to terminate
- Robust
In order to do this, I needed a way to plug an ethernet-style (8-pole 8-conductor) modular jack into a breadboard. I last built one of these breakout boards when I was working on my thesis at ITP. It was a time consuming process.
Since I’m planning to use these jacks in this project, it may make sense to create some printed circuit boards.
I’ve written previously about my process for etching boards, so I won’t repeat myself here. I use a laser printer to put the board design on glossy paper, transfer it to copper-clad board using a hot iron, and then etch away the excess copper using a solution of copper chloride in aqueous hydrochloric acid.
After etching, drilling, and soldering…
The completed prototype circuit works with two sensors. I wrote a patch in Max/MSP to trigger sounds when a person walks past.