I’d been looking for a way for my media PC to control the power of the other devices in that system (sub, amp, tv). I’d thought about X.10, but I felt that was expensive overkill.
After some investigation on maplin’s website, I found these.
These are RF remote controlled 4bars. Quite nifty, although I’m not that interested in the remote control bit as I need something the computer can control and know what state it is in (see earlier post about discrete IR codes). So I bought a couple of them as they were £13 each.
I got them home and opened one up:
Looks like a fairly standard digital board controlling a relay. Which, indeed, it was (I built a similar system to control my old water cooling system). The relay is switched on simply by supplying 5v. I removed the digital board and replaced it with a cable the computer could control:
And it works beautifully!
However, lets take a closer look at the digital board I removed:
The chip on the left is a PT4301-X, typically used for remote control systems such as car ignition, garage doors etc. The chip on the right is the interesting one from my point of view. Its a Microchip PIC16F630 (which is flash and therefore reprogrammable)! The port on the top right is the programming port for the PIC, and the port on the bottom is the 4 outputs from the PIC. There are two buttons on there as well. Effectively I have two rather nifty wee embedded programmable remote control development boards.
The remote control itself has an MDT2010 in it – again this is a reprogrammable microcontroller with 35 instructions and 1k of EPROM. (apparently it is based around the well known “COMS” technology *cough* *cough* 🙂
So: now I need to think of a project idea for an embedded remote control system. The box claims a range of about 30 metres in open air….
adq 