This following is re-post of an article from my old blog from 2008: This is an FM radio transmitter I made using an arduino and a NS73M FM Transmitter. I got the idea from an article on hack a day, if you’re interested in building your own you should check out Mike Yancey's page he built the one that made it on hackaday.com and he does a very thorough job of documenting how all the components hook together. I was impressed by the level of finishing he was able to achieve on the housing; it looked like a commercial product. I wanted to see if I could achieve a similar result, it’s amazing what you can do with some simple hand tools. If your patient with the file, you can make perfectly square holes in aluminum. On my implementation I omitted the de-bouncing circuit that he has connected to his rotary encoder, and I used a two-line display. Since I omitted the de-bouncing circuit, I couldn’t use the original rotary encoder library since that code uses a hardware interrupt a...
This is re-post of a blog post I did about 15 years back, I don't know if I would use an Attiny microcontroller if I was to do this today. The price of chips with built in USB is now cost comparable, and hardware USB is more reliable. But it's a fun project and if you happen to have a microcontroller compatible with V-USB it's worth a try. I was digging though some of my old junk and found a box of old Nintendo stuff and I thought that it might be cool to turn one of the controllers into a USB game pad. Now you can buy a USB NES style gamepad, but what's the fun in that. So, I started looking though my box of electronic parts and found a couple of Atmel Attiny 85 micro controllers. Sweet a chance to try out the AVR-USB library . Now you would think you need a clock crystal to sync the micro controller with the USB, but the AVR-USB library has an algorithm to calibrate the internal oscillator to within +/- 1% accuracy. Which is fortunate because if we had to use a cl...