I'm using ATmega169P in an application and just came across a need for an additional two ADC channels (0-3 are in use). Unfortunately on this part, ADC4-7 are muxed with JTAG pins. I've had no luck getting the micro to read those channels
Is it necessary to disable the JTAG interface via fuse settings in order to use these upper ADCs? That's a real drag for me... means I have to dig out my AVR-ISP to program it over SPI, and I won't be able to do any further debugging :(
[Obviously I am not expecting to use the JTAG interface simultaneously with having those pins work as ADCs. I just don't want to lock off the JTAG just yet...]thanks.