I'm now having strange issues with the DS18B20 sensors. The code (listed in the code section under 4ch Thermostat) should show NC if there is no sensor connected, but ch3 shows up as 655.4c... If I connect is sensor to Ch3 it correctly reads the right temperature, but then Ch2 displays 655.4c... but if both have sensors connected both read correctly. Ch1 and Ch4 work perfectly. I've checked the board, replaced the resistors between the data and +ve, even re-made the links between the PIC and the sensor input.
I'm testing the board by hooking it up to the Expansion port on the EP5, and have decoupling caps across the supply lines.
Any suggestions.... at least I've made some progress over the 1st prototype

Bookmarks