Rotary encoder success
I've been working on the little rotary encoder gadget that I took along to last month's Dorkbot Bristol. It's a CD-ROM hub/motor, stripped out of a broken drive and repurposed. I've wired up the three hall-effect sensors to give a signal that represents the rotation of the hub, and connected it all to an Atmel AVR ATmega8 microcontroller. I've also wired an LCD (16 chars by two lines) to the microcontroller, and written some code to drive it. I now have the rotary encoder's position displayed as a 32-bit number, in hex of course, and it increments if you spin the thing clockwise and decrements for anticlockwise.
Other than that, I've been thinking about the radio-controlled car chassis that I got the other day at the LUG meeting, and trying to figure out a way to add odometry. That is, count the turns of the wheels. Except, I need to do it more accurately than that -- I need a couple of hundred counts per turn of the wheels, so that I can maintain good control of the motor at low speeds. I don't think hall-effect sensors will do it for this one, so I'll try an opto-reflector type.
Today, I went shopping at the new Tesco shopping centre in Bradley Stoke. Amongst other things, Tesco seems to have a huge stock of cheap (£25) LCD photo-frames. Which, as usual, set me thinking about how good it would be to repurpose one of those as, say, a display for a 1980s home computer like the Compukit UK101.
Other than that, I've been thinking about the radio-controlled car chassis that I got the other day at the LUG meeting, and trying to figure out a way to add odometry. That is, count the turns of the wheels. Except, I need to do it more accurately than that -- I need a couple of hundred counts per turn of the wheels, so that I can maintain good control of the motor at low speeds. I don't think hall-effect sensors will do it for this one, so I'll try an opto-reflector type.
Today, I went shopping at the new Tesco shopping centre in Bradley Stoke. Amongst other things, Tesco seems to have a huge stock of cheap (£25) LCD photo-frames. Which, as usual, set me thinking about how good it would be to repurpose one of those as, say, a display for a 1980s home computer like the Compukit UK101.