Beginners • AS7341 Spectral Sensor on Raspberry Pi 5

Hi everyone,

I'm having trouble getting my AS7341 spectral sensor to produce any meaningful readings on my Raspberry Pi 5 with a Qwiic HAT.

Setup:

• Raspberry Pi 5 with I²C enabled
  Qwiic HAT connected via a proper JST-to-JST cable
  AS7341 Spectral Sensor (with onboard white LED)

What I've Tried:

Basic I²C Checks:

• Soft reset (0x80 → 0x10) and alive register (0x92 returns 0x24).
  Configured SMUX with 0x00 → 0x30 and 0x00 → 0x33.
  Enabled measurement mode (0xA9 set to 0x01, then 0x03, then 0x13) – registers confirm expected values.
  Set integration time manually (0x81 → 0xFF) and waited 10 seconds. STATUS (0xA3) shows a valid value (0x24), but channel registers (0x95–0x9C) read zero—even when read as 16‑bit words.

Python Testing:

• Used the Adafruit CircuitPython AS7341 library with long integration times (2000–5000 ms) and extra delays.
  The script times out with “Timeout occurred waiting for sensor data” or returns zero for all channels.

Issue:

• Sensor reports it’s alive and even completes a measurement cycle (STATUS register is nonzero), yet all spectral channels remain at zero. The onboard bright white LED turns on correctly from Python code.

Questions:

• Has anyone experienced similar issues with the AS7341 on a Pi 5?
  Any hints on integration time, SMUX settings, or LED interference that might cause this?
  Suggestions for alternative libraries or troubleshooting steps would be appreciated.

Thanks in advance for any help!

Statistics: Posted by kansas 3948 — Sat Mar 01, 2025 8:51 pm — Replies 0 — Views 29

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