So, I have to collect 10 or more differential voltages, and I know the Mega can't do that so I was looking for some sort of differential channel adc shield, but I found nothing. The range of voltages is 0-5 and I need to keep the resolution
Is my best possible option using an op-amp with no gain? Or are there other ways?
Pair of 16-to-1 analog switches? 74HC4067's
so collect 2 voltages per each measurement and subtract them from each other? well what if their single ended inputs are 15V+.....voltage dividers? there has to be a better way...unless I am missing something here
Maybe look into ICs like this
or this
in both cases, need a good mux in front to select the inputs to be sampled.
Or perhaps a Simultaneous Sampling part, capture 2 inputs together for trueest differential measurement.
May need to scale down your input a touch.
Another option is to run your signal thru a differential amplifier first and then just sample 1 signal.
If they are +/-15v signals, would have to divide them down some for sure, can't have a +30V to -30V input in any device that I've seen.
sunssoldier:
So, I have to collect 10 or more differential voltages, and I know the Mega can't do that so I was looking for some sort of differential channel adc shield, but I found nothing. The range of voltages is 0-5 and I need to keep the resolutionIs my best possible option using an op-amp with no gain? Or are there other ways?
If you wanted something more off the shelf, I noticed the Pololu Maestro 24-channel controller (for up to 24 servos), can also do up to 12 digital inputs, and 12 analog inputs. Now, 12 doesn't give you much growth path from the 10 inputs you want now, but perhaps you can get two boards if you need more than 12 inputs. Note, I haven't used any of the Maestro boards, so I can't say how they work in practice.
Difference Amplifier
http://www.analog.com/static/imported-files/data_sheets/AD8278_8279.pdf