Nau7802 sampling rate

Sensors Force & Weight
1

Hi,

I am getting started with the Arduino and Nau7802 load cell sensor and am using a barely modified example code (“Example2_CompleteScale”). I am studying the output through the built in serial port monitor in the Arduino software.

The sampling rate of my data seems to be 1/9 of the nominal rate.

For example, if I set the sample rate to NAU7802_SPS_320, presumably 320 samples per second, I actually acquire data at 35.5 samples per second. NAU7802_SPS_80 gives 8.9 samples per second. NAU7802_SPS_10 gives 1.1 samples per second.

Always 1/9 of the nominal rate.

I notice that Nuvoton’s documentation refers to “conversion rate select,” CRS, but also uses the acronym SPS, presumably samples per second. Is there a difference?

Any insight would be appreciated.

Thanks,

Andrew

2

Well, I’ve found a partial answer to my own question.

I can sample at 320 Hz if I restrict myself to “getReading” calls only in the loop of my Arduino program.

I don’t believe I use anything else from the Sparkfun Qwiic Scale Nau7802 Arduino Library within the loop. Something in there in the example code is reducing the sampling rate by a factor of 9.

This suits my needs because I can then process the raw data myself after the data collection. So I am satisfied.

Andy