zackfine123
New member
Hi,
I am working on a project involving 300kg S-type load cells connected to an HX711 then connected to a teensy 4.1. The HX711 is running on 3.3V (which i believe should be ok, I have tried both with and without modifying the HX711 board following this: https://hackaday.io/project/1741-ho...ng-the-hx711-breakout-board-for-33v-operation but it doesn't seem to make a difference for my problem).
The issue I am having is that the load cell seems to read almost on two different scales depending on the load, with values around 8000000 when under some tension, and values around 100000-500000 when under compression. These values do increase in the direction I would expect in both cases, which makes think the issue isnt saturation of some kind. The loads I am using are well within the range the load cell can handle. The point at which it changes is not at 0 load, its around 100N of tension I think. I need to use the full range of the load cell (~2kn in either direction) for my project. I am pretty sure all of my hardware works, but if anyone has a good reference for easy ways to test it again that would also be helpful. I have two load cells in the same configuration and both have this issue when connected to the teensy.
This issue has been plaguing me for a long time and I have tried everything under the sun to try to fix it. I have checked and rechecked the wiring at least 20 times, tried using a voltage divider to step the sck and dout signals down to 3.3V while powering the HX711 at 5V, but nothing has worked. I ran the same HX711 and load cell on an arduino mega and did not have the same problem.
For simplicity while diagnosing my issue I have been using the stock Rob Tillart HX711 library's calibration sketch to read it, and added the output below for a test where I went from compression to tension (true read is the output of load_cell.read_average()).
Let me know if there's any information I could provide to make solving this easier. Thanks in advance!
I am working on a project involving 300kg S-type load cells connected to an HX711 then connected to a teensy 4.1. The HX711 is running on 3.3V (which i believe should be ok, I have tried both with and without modifying the HX711 board following this: https://hackaday.io/project/1741-ho...ng-the-hx711-breakout-board-for-33v-operation but it doesn't seem to make a difference for my problem).
The issue I am having is that the load cell seems to read almost on two different scales depending on the load, with values around 8000000 when under some tension, and values around 100000-500000 when under compression. These values do increase in the direction I would expect in both cases, which makes think the issue isnt saturation of some kind. The loads I am using are well within the range the load cell can handle. The point at which it changes is not at 0 load, its around 100N of tension I think. I need to use the full range of the load cell (~2kn in either direction) for my project. I am pretty sure all of my hardware works, but if anyone has a good reference for easy ways to test it again that would also be helpful. I have two load cells in the same configuration and both have this issue when connected to the teensy.
This issue has been plaguing me for a long time and I have tried everything under the sun to try to fix it. I have checked and rechecked the wiring at least 20 times, tried using a voltage divider to step the sck and dout signals down to 3.3V while powering the HX711 at 5V, but nothing has worked. I ran the same HX711 and load cell on an arduino mega and did not have the same problem.
For simplicity while diagnosing my issue I have been using the stock Rob Tillart HX711 library's calibration sketch to read it, and added the output below for a test where I went from compression to tension (true read is the output of load_cell.read_average()).
Let me know if there's any information I could provide to make solving this easier. Thanks in advance!