# HX711 zero factor

I have three load cells (YZC-1B). These load cells' capacity is 50 kg. I guess I use Bogde's HX711 library.

In monitor, the zero factor for the first two load cells is 8,000,000, but for the last load cell the zero factor is 40,000. When I swap the green and white wires (swap A- and A+), the zero factor is again 8,000,000, but the last zero factors (8 million) are negative and my load results have got a negative value.

When I look at the logic analyzer, I took 000000010110100111011010 converted to decimal, the result is 92634. My zero factor is -46377 (in -46377 load results look good).

Question 1, long zero_factor = scale.read_average(); in the library; why are these zero factors always split in two?

Question 2, Why do zero factors' values have negative values?

Question 3, Why is the last load cell's zero factor -46377?

• This version of HX711 library for Arduino? github.com/bogde/HX711. Jan 8, 2022 at 14:23
• @tlfong01 yes for arduino. Jan 8, 2022 at 14:32
• (1) YZC-1B has a max capacity of only 40kg: fr.aliexpress.com/item/32225995715.html. (2) Please give exact specific links to your (a) library and (b) load cell. Jan 9, 2022 at 12:58
• @tlfong01 thank u for ur comment. My load cells datasheet here says 40 or 50kg capacity. ardu.dk/wp-content/uploads/2015/03/Vejecelle-YZC-1B.pdf. I use bogde's library. I got a reference from this link; electroniclinic.com/… Jan 9, 2022 at 18:23
• (1) my calibration factor is different for each load cells. For example; 1kg load cell's calibration factor is 217, 50kg load cell's calibration factor is 45-43. (4) how can I use a multimeter for calibration idk, can you share a link about that? I couldn't get why I must use less bit ADC . Jan 12, 2022 at 19:20