HX711 strain gauge amp with 24 bit serial o/p

tritonium

Hi all
Just come across this

http://www.ebay.co.uk/itm/HX711-Electronic-weighing-sensor-module-24-bit-Dual-channel-ADC-Rasp-Pi-Arduino-/141361163400?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item20e9c82c88

HX711 24 bit strain gauge amp with digital serial o/p.
It has two sets of differential inputs (selectable) which I would think could be used as a voltmeter with 24 bit accuracy with the right input conditioning.
+- 20 mV for full scale reading
There must be all sorts of uses other than the actual intended one and for this price sounds like fun.
Has its own serial protocol for the bitbangers amongst us!

Dave

Heater.

tritonium,

...with the right input conditioning...

And there is the problem.

To use this as a volt meter are going to want to divide everyday voltages (1v to 1000v full scale say) down to 20mV. With your typical 0.1% precision resistors you are are throwing away most of that 24 bit, or one part in 16 million precision of the ADC.

Down at microvolt levels like that noise is going to be a problem.

jones

Unless you have some really small voltages to measure, I'd think it would be better for measuring current. The low voltage range would be an advantage when measuring current since it would allow the use of a smaller sense resistor which reduces losses. Also, for measuring tiny currents that generally require large value resistors, lower value precision resistors are cheaper.