 # Using second fixed gain input on hx711 -- possible resolution

I discussed with @Clemens today if it would make sense to use the second input on the Hx711 chip with fixed gain of 32.
I calculated something. Maybe somebody can verify that?
I used this datasheet of the Hx711

Assuming we have 3V input and a load cell with 2mV/V on rated output (maximum):

``````input range: (=0,5*VDC/GAIN) = +- 50mV
resolution with 24bit on +-50mV ~ 100mV: 100mV/(2^24) = 6 * 10^-6mV
rated output of load cell with 3V = 3V*2mV/V = 6mv
therefore the rated output is divided into 6mV/(6*10^-6)mV = 10^6 = 1 mio steps
assuming a maximum range for one load cell from 0 - 100 kg we find: 100kg / 10^6 = 0,1g resolution!
``````

0,1g resolution
That would be quite funny as this is the weight of one bee ;-)

Das schreiben die Kollegen von beelogger dazu:

https://beelogger.de/?page_id=194448

@Clemens keep in mind, you probably will not be able to use all 24 bits of ADC resolution due to noise. I believe, more realistically, you can count with 16-18bits (e.g. 262 144) of resolution.