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

Hardware
6

Hi @pammy and Realtek Team,

I’m building a battery-powered smart scale on AMB82-MINI (RTL8735B) and have two blocking issues that force me to stay on SDK 4.0.9. I’d appreciate any guidance.

Issue 1: Dual wake-up sources in Deep Sleep (AON Timer + AON GPIO)

Need: Wake from deep sleep by AON GPIO pin 21 (LDR/comparator, rising edge) AND AON Timer (60s periodic) simultaneously.

Context: I found the multiple-wakeup patch in thread #4805 — thank you for sharing it.

Problem: The patched PowerMode.cpp uses amb_ard_printf(ARD_LOG_ERR, ...) which exists in SDK 4.1.x but does NOT exist in SDK 4.0.9. I had to manually replace these calls with Serial.println() to compile under 4.0.9.

Questions:

  1. Which SDK version officially includes the multi-wakeup patch?
  2. Is there a 4.0.9-compatible build of this patch, or should I wait for a backport?

Issue 2: SPI1 regression in SDK 4.1.x breaks ADS1256 ADC

Setup: ADS1256 24-bit ADC via SPI1, MODE1 (CPOL=0, CPHA=1), 500 kHz.

Observed on SDK 4.0.9-build20250805:

  • SPI1.transfer() does not read MISO — always returns 0x00
  • SPI1.masterWrite() works correctly as a full-duplex replacement
  • All ADS1256 communication is built around masterWrite()

Observed on SDK 4.1.0-build20260202:

  • The same code and wiring that works on 4.0.9 produces invalid / garbage data from ADS1256
  • masterWrite() either changed behavior or was removed/modified

Minimal reproducer:

#include <SPI.h>

static inline uint8_t spiXfer(uint8_t b) {
  return SPI1.masterWrite(b);  // Only API that reads MISO on 4.0.9
}

void setup() {
  Serial.begin(115200);
  SPI1.begin(SPI_MODE_MASTER);
  
  // Send STATUS register read command to ADS1256
  uint8_t status = spiXfer(0x10); // RREG STATUS
  Serial.print("STATUS = 0x"); Serial.println(status, HEX);
  // 4.0.9 → 0x30 (correct)
  // 4.1.0 → 0x00 or random (incorrect)
}

void loop() {}

Questions:

  1. Was SPI1.masterWrite() intentionally changed or deprecated in 4.1.x?
  2. What is the recommended SPI API for full-duplex MISO reads in 4.1.x?
  3. Is there a migration guide for SPI code from 4.0.9 → 4.1.x?

The Catch-22

I need dual wake-up sources (patched in newer SDK) AND working SPI1 (broken in newer SDK). Currently I cannot use the latest SDK because of SPI, and the wake-up patch requires manual adaptation for 4.0.9.

Any ETA on when both features will be stable in a single release?

Thanks!