Tinkering with Electronics

I wrote an earlier post about powering up the Intellitouch and Easytouch boards on my test bench, so I thought I'd add one about how I power up the Intellicenter... To power these boards I use a bench/lab DC power supply because it lets me see and control the voltage and current supplied to the device.  The only significant difference with the Intellicenter is the voltage used... I use 12 volts DC (vdc) on the Easytouch/Intellitouch and 24vdc on the Intellicenter. It's safe to connect a 24vdc source to the 18vac pins because the AC voltage at the input gets converted to 24vdc by the rectifiers/caps, and you can feed DC through a rectifier... I connect my leads using the polarity shown in the pic below, and if I use less than 21vdc, the the machine doesn't boot.  If you only have an 18vac source you don't need to worry about polarity. The other two 24vac input pins can be left disconnected if you don't need the valves to work, or you can use any 24vac source you'...

 A few years back I posted about the difference between an Easytouch 1 and 2... basically the Easytouch "revision 2" is a newer hardware revision but uses the same exact board and components as the Easytouch 1, except for the microcontroller which has 128k of flash instead of 64k.  This means you can update a revision 2 board with the latest 2.x firmware versions.  You can see the original article here . Since posting that article, I've wanted to swap the microcontroller on a "V1" Easytouch with one that will make it a "V2" Easytouch... I finally did it and it works!  Figured I'd document the process in case anybody else felt like tinkering... To do the swap, my first step was to get a microcontroller with 128k flash... I had an Easytouch V2 remote with a bad keypad, so I cut it open to grab a donor chip. The indoor, outdoor and wireless controllers all use the same microcontroller but they have different firmware. The reason I used a donor chip wa...