
We’re used to central A/C, so we were surprised by this PIC controller based heater controller. It’s based around a pump controlled boiler/radiator system. A PIC 16F84 is used to input the set point and control a pump to circulate the heated water as needed. You can grab full schematics on the project page.
Update: We added a screen capture of the schematic after the break since the site keeled over.



