A project log for LOAD CELL to MODBUS

It's not a toy! It's the device for using in industrial weight measurement systems for trucks, trains, and conveyors.

Andrey VAndrey V 08/20/2019 at 18:580 Comments

Some measurement of sensor and ADC noise.

I wrote a simple software to measure sensor noise and get the noise-free count. 

Test setup:

Left to right: 0.2ton Load cell, my Load cell - Modbus interface, IOTON MICRIO MPU & DI8 input module.

500 counts noise video:

As you can see, I have around 120 counts of noise Peak-to-Peak.

Lets calculate the counts... 24bit = 2^24 = 16 177 216 counts. Noise of my system = 120 counts. So I will have 16 177 216 / 120 = 134810 noise free counts, it's around 17 bits. Not so bad.

For 200 kg load cell (actually it's 400 kg load cell, because 200kg for compression and 200 kg for tension) I will have an accuracy of around 200 000 * 2 / 134810 = 3 gram.