SparkFun Qwiic Scale - NAU7802 scale with labVIEW LINX

Qwiic System
1

I have purchased a SparkFun Qwiic Scale - NAU7802 breakout board and I am connecting the same with Arduino Uno R3 and interfacing with LabVIEW 2019 (with LINX).
I am unable to read data from the bar type load sensors.
I am unable to find any example LabVIEW codes to help me out.

Any pointers would be appreciated. The NAU7802 data sheet is not very clear to me as to what commands I should use and the address of the registers to get the data over I2C protocol.

P.S. I have used Labview (Linx) with SHT85 sensor on I2C protocol, thanks to the detailed datasheet, it was pretty easy.

2

Can you get it as far as Example 1?
https://learn.sparkfun.com/tutorials/qwiic-scale-hookup-guide

3

^Like he said, check out the hookup guide…the i2c address is 0x2A and just above example1 the library’s relevant registers are listed

4

Hi @brow , thanks for your reply. I understand Example 1 but I still can’t find the hex addresses to instruct/write to the Nau7802.

I will tell you what I did for STC31 sensor.

STC31 had the commands/addresses mentioned in the datasheet (check image below)

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image751Ă—793 175 KB

Based on this, I was able to get a LabVIEW LINX code implemented as shown below:

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image1337Ă—529 115 KB

For Nau7802 I am not able to find/figure out these hex/binary commands to write to.

I tried to look above example 1, but I cant see the hex/binary commands to write to the 0x2A address. Only thing I was able to understand is that the device address is x2A (in Hex).

Is there a way to find the Hex commands?

5

Example 1 does not ask the student to interpret those commands; it relies on the provided library.
You can write your own based on the register tables given in the specsheet:

I only skimmed it but think it shows a few options on page 34 (typos are the original author’s):

There are two options are necessary read a complete 24 bit ADC conversion result:

I still recommend stepping through the examples before attempting the more difficult stages.

2 Likes
6

Hello all,

Based on the suggestion of @brow , I have gone ahead and created a 2 wire burst mode reading of Nau7802 ADC converter using LabVIEW VI.

The hardware includes any 4 wire, bar type load cell connected to NAU7802 based Sparkfun Qwiic Scale which in turn is connected to Arduino Uno R3.

I have used Linx “plugin” in labVIEW to communicate with my Arduino Uno R3 board.

Since I cannot upload my VI (limitation of this reply box), I am sharing a “labelled” VI picture. The VI works with the default setting of ~80 Hz (sps) frequency.

Please note that in the future I will enable ways to set the sampling rate, etc.

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image1560Ă—427 15.7 KB

1 Like
7

Good job! You can always post a link to a google drive file or similar if you want to share the file :smiley: