Load Cell Amplifier Recommendations for Ameba Pro2 Mini - Both NAU7802 and HX711 Failed

Hardware
1

Hello Ameba community,

I’m working on a load cell project using Ameba Pro2 Mini (AMB82-mini) and need recommendations for a load cell amplifier that works reliably with this platform.

Current Situation:

I’ve tried two different amplifiers but both failed:

  1. NAU7802 (24-bit ADC, I²C interface):

  • I²C scanner detects device at address 0x7E instead of expected 0x2A

  • Register writes fail (all registers read as 0x0 after write attempts)

  • Adafruit NAU7802 library has compilation issues with Ameba toolchain

  • Direct I²C register access doesn’t work reliably

  1. HX711 with level shifter:

  • Used TXS0108E 8-channel logic level converter (AZDelivery module)

  • Connected: HX711 (5V side) → TXS0108E → Ameba Pro2 Mini (3.3V side)

  • Tried multiple libraries: standard HX711_ADC, custom GPIO implementations

  • Result: No data received, readings are zero or invalid

Questions:

  1. Recommended Amplifier:

  • Which load cell amplifier actually works with Ameba Pro2 Mini?

  • Has anyone successfully used HX711, ADS1232, or other 24-bit ADCs with Ameba?

  • Are there known compatibility issues with load cell amplifiers on this platform?

  1. HX711 Issues:

  • What could be wrong with my HX711 + level shifter setup?

  • Should I power HX711 from 3.3V instead of 5V (HX711 supports 2.6-5.5V)?

  • Are there specific GPIO pins or timing requirements for Ameba?

  • Any working code examples for HX711 on Ameba Pro2 Mini?

  1. Level Shifter:

  • Is TXS0108E the right choice, or should I use a different level shifter?

  • Could the level shifter be causing signal integrity issues?

  • Should I avoid level shifters entirely and use 3.3V-powered HX711?

Technical Details:

  • Load cell: 40kg capacity, 3-10VDC excitation, 1.1mV/V sensitivity

  • Ameba Pro2 Mini: Realtek AMB82, Arduino-compatible framework

  • HX711 setup: 5V power, DT/SCK through TXS0108E level shifter

  • NAU7802 setup: 3.3V power, I²C at 100kHz/400kHz

What I’ve Tried:

  • NAU7802: Direct I²C register access with various delays, different clock speeds, both addresses

  • HX711: Multiple libraries, different GPIO pins, level shifter on both sides, direct connection (damaged module)

  • Both: Verified connections, checked voltages, tried different load cells

I’m stuck and would appreciate any guidance, working code examples, or alternative solutions.

Thank you in advance.

2

Hi @inxnik

Currently, our SDK doesn’t include official support for load cell amplifiers. However, the two amplifiers you mentioned should still work with the AMB82 Mini. We’ll review this internally and support it in future SDK update.