SparkFun Forums 

Where electronics enthusiasts find answers.

User avatar
By keebler411
I followed the industrial IoT tutorial and have a scale working with the NAU7802 chip. I used a combinator board to connect the for load sensors. However, I can't replicate the setup to another 4 sensors. I've soldered up 2 sets of sensors and get the same results:

1) If I leave A+/A- connections the same as with the scale that works I get a really large number (shy of 24 bit max value) and it doesn't change much unless a huge force is applied

2) If I reverse A+/A- I get a no load reading in the same range as the working scale

3) If I now apply gradual pressure with say my foot I see the reading decrease until it underflows and I get a large number like before

4) Within the range of no load to just before underflow I can calibrate the scale and get a slope that is about the same magnitude as the working scale (good), but obviously negative because I reversed the connections.

I've carefully checked the connections and had other people check them too. Any ideas?
User avatar
By TS-Chris
Hi keebler411.

What load sensors are you using and how do you have them wired up to the NAU7802 breakout? Can you provide some photos showing your connections? If you could also send some photos of the top and bottom of your board that would be helpful too.