Hello, I have source I want to read voltage from. It varies between 1.5-4 volts. I only need reading from 1.5 to 2.5 volts, but i would like to have good resolution. So, is it possible to read it with gain setting of 4 (+-1volt) ?

[image] hautamak: I only need reading from 1.5 to 2.5 volts, but i would like to have good resolution. So set the gain for a FSR (Full Scale Range) of +/-512mV Connect your 1.5-2.5V signal to AIN0 and connect 2V to AIN1. The differential signal will be +/-500mV The resolution will be 1.024…

4.096 / 32768 = 125uV steps. Tell us more about this EMF sensor. The ADS might be too slow for the frequency too. Leo..

Okay. I did some miscalculations. Seems that it is enough. Its old analytic balance with emf load cell. It's making voltage to change from 4 volts (0 grams) to 1.5 volts (60 grams) Accuracy is 0.0001g for the scale, bit unfortunately the original pcb Don't have output for arduino, so I have to tak…

24-bit HX711 breakout boards are commonly used for load cells, not ADS1115. The HX711 also provides a stable excitation voltage (4.25volt) for the load cell. Leo..

[image] hautamak: 4 volts (0 grams) to 1.5 volts (60 grams) Since the ADS1115 resolution is 15 bits plus sign, there are 32767 steps between 0V and 4.096V or roughly 7 milligrams per ADC step. That seems hardly worth the effort.

24-bit HX711 breakout boards are commonly used for load cells, not ADS1115. The HX711 also provides a stable excitation voltage (4.25volt) for the load cell. Leo.. How do I connect the hx711 to scale? Can it read values from 1.5volts to 4 volts? I looked datasheet and seems that maximum voltag…

[image] hautamak: How do I connect the hx711 to scale? Can it read values from 1.5volts to 4 volts? No, the HX711 is useless for your application. You need a 24 bit ADC with an input range of at least 4V

[image] jim-p: You need a 24 bit ADC with an input range of at least 4V The LTC2485 might be an option [image] GitHub - RobTillaart/LTC2485: Arduino library for LTC2485 I2C 24 bit ADC. Arduino library for LTC2485 I2C 24 bit ADC. It was recently…

[image] Wawa: I doubt you understand differential readings. Differential is the difference between two voltages, but they both must be between Gnd and VCC. So, if I have ground and two inputs 5v stable and 3-4 volt changing can I use the more accurate input? (Pga 2)

[image] hautamak: can I use the more accurate input? All the inputs have the same accuracy

I meant the voltage range. Voltage from ground is over 2v , but voltage difference is under 2 volts. So, is the pga 2 range from ground or difference between voltsges?

Ads1115 differential mode

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robtillaart April 12, 2025, 9:10am 14

The LTC2485 might be an option

It was recently co-developed and tested by @vitaliykrym here

LTC2485 arduino library

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Ads1115 differential mode

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