I'm looking for a the simplest way to do a low-frequency, high-resolution lock-in solution for multiple 4-wire rtds. (If I can't find one, I'll try the AD7794 without lock-in.)
The DAC output will be sine or square at 10-100Hz and resistor-divided down into the mV to µV-range. I have long leads, and it seems lock-in would be (nearly) the only way to go. Neither price nor size play a role. only accuracy, precision and ease of implementation play a role.
I'm sure a PSoC (ADUCxxx) would do the job, but it's difficult to know which one. Which chip should I be looking at?
Are there any examples of lock-in code for such chips? Does anyone have experience with such projects?
I can't afford to spend half a year programming without knowing what the outcome will be, so if anyone has experience or has alternative strategies, I'd be grateful to hear. All and any information or pointers will be of help to me.