HX711 + 4 load cells output issue

Hardware
1

Hi,

I’m not sure if this is the right place to ask for help, but I’m kind of lost trying to figure it out myself. I connected a NodeMCU to a HX711 to 4 load cells according to this post:

And hooked all the wires up according to the schematic from the guide.

image
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The problem I’m facing is that the output of the values change in the wrong direction. When I have no weight on the load cells the out put value is 23k and when I load ~1,5kg on the load cells the value goes to 21k.

I read somewhere that if this is the case you should switch the white and the black wires around. So the two load cells which were connected with white wire would now be connected with black wires and the other way around. Even thought the values go up now, they are negative. So without load it gives me -23k as output and with adding ~1,5kg it gives me -21k as output.

I tried to figure out what is causing this, but no matter what I try I get the same results.

I’m a hard time finding someone with a similar problem online, so any help is apreciated.

2

Hi,

I got the same issue.
I followed this wiring (dont mind the arduino) with an ESP32 and a HX711AD.
grafik

Are you using the Red or the Green version?
grafik
grafik

I am using the green version.

esphome:
  name: bedsensor
  platform: ESP32
  board: esp32dev
  platformio_options: 
    platform: espressif32
    board: az-delivery-devkit-v4
    board_build.mcu: esp32
    board_build.f_cpu: 240000000L
wifi:
  ssid: "------"
  password: "------"

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "-------"
    password: "------"

captive_portal:

# Enable logging
logger:

# Enable Home Assistant API
api:
  password: "----"

ota:
  password: "-----"



sensor:
  - platform: hx711
    name: "HX711 Value"
    dout_pin: GPIO21
    clk_pin: GPIO22
    gain: 128
    update_interval: 20s
    unit_of_measurement: "kg"

Maybe this might help you…

3

Thanks for the reply.

I’m using the green version as well.

In the end I connected everything with the reversed wiring and flashed it with Tasmota instead following the video of ‘The hook up’ and simply put an offset of +23k to reach 0.