Best way to interface strain gauges with nRF528xx

[drewvigne]

My team is developing a bike power meter, so we are looking to shrink our PCB design as much as possible. We are directly measuring force using an array of strain gauges. 

Of course we will need an ADC to accomplish this, I’m just wondering what the best direction should be. We have experimented with the HX711 during prototyping although it is quite large and requires extra software, configuration, etc... does Nordic have a recommended external ADC, perhaps one that takes advantage of UART or TWI?

Or alternatively, and maybe ideally, is it possible to directly wire the strain gauges to the built-in SAADC on the nRF5832? I just realized today that this may be a possibility. I didn’t know you guys built this in.

[awneil]

The hard part of anything like this is getting the analogue bit right.

You will never achieve the full potential of any ADC if the analogue signal is sub-optimal before it reaches the ADC's inputs!

The HX11 is not just an ADC - it also has all the analogue signal conditioning built in.

Unless you're an analogue design expert,  this would certainly be the way to go.

EDIT

I'm sure the HX11 is not the only such chip available - it shouldn't be hard to have one that has a standard interface.

But it really makes no difference to the nRF what you choose

[drewvigne]

Good point and something to consider.