FAQ
TL;DR: Fix BK7231N + CHT8305 IR receivers showing stuck values, set correct pins, and use CHT_Cycle for a 60 s sample interval—"a CHT_Cycle command has been added." Advanced IR decoding needs the PR build. [Elektroda, DeDaMrAz, post #20588089]
Why it matters: This FAQ helps OpenBK7231N tinkerers fix CHT8305 misreads and enable IR decoding on Tuya IR remotes without the cloud.
Quick Facts
- Typical pin map: P6 SDA, P26 SCL (CHT8305); P8 IRSend; P24 IRRecv; P15 LED_n; P17 WiFi LED; P28 Button. [Elektroda, DeDaMrAz, post #20560227]
- Tuya chose a step‑down converter for efficient 3.3 V, not an AMS1117 LDO. [Elektroda, p.kaczmarek2, post #20560614]
- U1 marking “bPDGG”; contributor matched it to an MP2128DG‑class buck, unconfirmed. [Elektroda, DeDaMrAz, post #20560630]
- Failure mode: short on CBU pin 18 (CEN) broke sensor reads; cleaning restored CHT8305. [Elektroda, baidedov5, post #20586049]
- New command: CHT_Cycle sets sample interval (e.g., 60 s) and works from autoexec.bat. [Elektroda, DeDaMrAz, post #20588089]
How do I map pins for the BK7231N IR receiver with a CHT8305 sensor?
Use the shared CBU template. Assign: P6 → CHT8305_SDA, P26 → CHT8305_SCK, P8 → IRSend, P24 → IRRecv, P15 → LED_n, P17 → WifiLED, P28 → Btn. This matches the posted working JSON. Export or import the template via the Web App. After saving, confirm two channels appear for temperature and humidity. [Elektroda, DeDaMrAz, post #20560227]
My CHT8305 shows wrong values until I press the button. What hardware issue caused it?
A thin solder whisker shorted CBU pin 18 (CEN) to the adjacent pin. That short forced bad readings. Cleaning the spot restored normal operation. Inspect the module edges under magnification and remove any bridges. After clearing the short, the sensor worked without button presses. [Elektroda, baidedov5, post #20586049]
Why do I see 125.000000 b0C and 100% humidity, then one valid sample after a short press?
Logs showed 125.000000 b0C and 100% humidity repeatedly, with one normal sample like 21.976654 b0C and 57.361713% after a short press. That pattern points to a compromised sensor path or intermittent bus. Check wiring and module pins carefully. If needed, reset the device and re-test only the sensor roles before adding others. [Elektroda, baidedov5, post #20585737]
How do I reset and test only the CHT8305 after flashing?
Try this:
- Run ClearConfig in the console, then reconnect through the AP.
- In Configure Module, set only CHT8305 GPIO roles and two channels.
- Check the Web Log for stable values, then add IR and LEDs. [Elektroda, p.kaczmarek2, post #20585942]
How do I decode and read IR codes in OpenBK7231?
Basic protocols like Samsung and Sony decode in the stock build. For broader coverage and AC remotes, use the IR-improvement build from PR #723. "There is a pull request for better IR." Download the PR’s build artifacts, flash the binary, then watch the Web Log while pressing remote buttons. Ensure IRRecv is assigned on the correct GPIO. [Elektroda, p.kaczmarek2, post #20586314]
Nothing shows when I point my AC remote at the device. How can I capture codes?
Assign the IRRecv role to the IR receiver pin and open the Web Log. If nothing appears, flash the PR #723 build that adds improved IR decoding for complex AC protocols. Many air-con remotes use nonstandard frames that the stock firmware may not parse. Retest after flashing the PR build. [Elektroda, p.kaczmarek2, post #20586314]
What do the Flags do, and where can I change them?
You can change Flags in the Configure Flags menu in the Web UI. Values may differ between devices or templates. Adjust only if your template specifies a value. Decimal-heavy log values relate to debug formatting, not Flags. [Elektroda, p.kaczmarek2, post #20585842]
Why does the Web App log show so many decimal places?
The Web App log is primarily for debugging, so rounding was not added. Expect full-precision floats there. The WWW panel may show cleaner values, but the log remains detailed for diagnostics. [Elektroda, p.kaczmarek2, post #20585842]
Power issues: should I try PowerSave or a different power supply?
Yes. Test PowerSave 1 from the console and try another power supply. These steps help isolate rail stability or noise issues that can affect sensors and peripherals. Use them during troubleshooting to check if behavior improves. [Elektroda, p.kaczmarek2, post #20586013]
What regulator does this board use instead of AMS1117-3.3?
The teardown notes a step-down converter provides the 3.3 V rail. This improves efficiency and reduces bulk versus an AMS1117 LDO. The regulator is marked as U1 on the silkscreen. It’s a better match for Wi‑Fi loads. [Elektroda, p.kaczmarek2, post #20560614]
Can we identify the U1 regulator with marking bPDGG ?
A contributor matched it to an MP2128DG-class buck regulator and shared the datasheet link. The exact identification remains unconfirmed due to custom marking. Treat it as a similar device reference until proven. [Elektroda, DeDaMrAz, post #20560630]
How do I set a periodic sample interval for the CHT8305?
Use CHT_Cycle. Example: CHT_Cycle 60 sets a 60-second interval. Add the same line to autoexec.bat to persist after reboots. This complements the CHT driver and lets you tune reporting for your application.
- Open Console.
- Run CHT_Cycle 60.
- Add to autoexec.bat and reboot. [Elektroda, DeDaMrAz, post #20588089]
Was the root cause software or hardware in the reported case?
Hardware. "So it was a hardware issue..." After clearing a short near the CEN pin, readings normalized. The firmware and configuration were fine. This outcome supports checking for physical faults early in troubleshooting. [Elektroda, p.kaczmarek2, post #20586314]
Where can I get and save a working template for this device?
Use the Web App template tools to fetch and store profiles. The shared post includes a ready JSON for this BK7231N + CHT8305 IR controller. Load it, adjust fields, and save locally. This speeds repeat flashes and keeps pin roles consistent. [Elektroda, DeDaMrAz, post #20560227]
![[BK7321N] IR smart receiver with CHT8305 sensor with CBU module](https://obrazki.elektroda.pl/6322441900_1682779470_thumb.jpg "[BK7321N] IR smart receiver with CHT8305 sensor with CBU module")
![[BK7321N] IR smart receiver with CHT8305 sensor with CBU module](https://obrazki.elektroda.pl/8314935200_1682779474_thumb.jpg "[BK7321N] IR smart receiver with CHT8305 sensor with CBU module")
![[BK7321N] IR smart receiver with CHT8305 sensor with CBU module](https://obrazki.elektroda.pl/5448998900_1682779603_thumb.jpg "[BK7321N] IR smart receiver with CHT8305 sensor with CBU module")
![[BK7321N] IR smart receiver with CHT8305 sensor with CBU module](https://obrazki.elektroda.pl/6322441900_1682779470.jpg "[BK7321N] IR smart receiver with CHT8305 sensor with CBU module")
![[BK7321N] IR smart receiver with CHT8305 sensor with CBU module](https://obrazki.elektroda.pl/8314935200_1682779474.jpg "[BK7321N] IR smart receiver with CHT8305 sensor with CBU module")
![[BK7321N] IR smart receiver with CHT8305 sensor with CBU module](https://obrazki.elektroda.pl/5448998900_1682779603.png "[BK7321N] IR smart receiver with CHT8305 sensor with CBU module")
