Freelancer to connect a load cell, ADC (HX711?) to nRF52DK (810)

[FreddyH]

We are looking for a freelancer who can help to build a simple Proof of Concept of a load cell (strain gauges) ADC (HX711?) and the nRF52 development kit (810).

Objectives are to show this bacon function works and to determine what the battery lifetime will be of the standard CR2302 battery.

Advertising only when the load change is beyond a certain threshold/level and when the signal is stable (low standard deviation).

We have components available (need instructions how to connect). 

 

[PXL]

Hello,

Managing the HX711 is fully achievable with the nRF DK (did it with a nFR52840 DK).

Using the onboard ADC with a strain gauge, as suggested by Karl, will provide you more noise than valuable value; so keep on with the HX711 and its integrated amplifier.

The consumption will greatly depends on the sampling rate, the transmission rate and the transmission power ; don't know what the intend of your beacon so can't figure what figure will have to be set to all this parameters (but think you already think on that).

I've same question as Karl; why are you mentioning nRF52810 as you DK is a  nRF52832 one (even you DK is backward compatible with 810) ?

Regards.

[FreddyH]

Dear PXL, 

thank you for your reply and suggestion t continue with the HX711. We indeed do so.

Regarding the nRF52810 vs the nRF52832: cost price is the main reason to select the 810. 
This was suggested by our Nordic contacts.
Do you have different experiences?

Best regards
Freddy

[PXL]

As it was an POC, I'd been upset you already restrict, put limitation on the Hardware.

My customer only need a set of sensor for a single install, price of the nRF is not a concern. That's understandable you integrate design to cost approach from the beginning.

The only advantage (in my context) of 840 over 810/832 is the maximum TX power (+8dBm); that allow better range.

Regards