FAQ
TL;DR: On a W600 RGBCCT bulb, 5 PWM channels now work; “All 5 PWM channels … work well.” Update firmware, map pins, and use the 0% off fix. [Elektroda, DanteBC, post #20884822]
Why it matters: This helps makers fix dimming and true-off behavior on W600-based RGBCCT bulbs using OpenBeken.
Quick Facts
- Proven pin map for one W600 RGBCCT bulb: Red=PA5, Green=PB13, Blue=PB15, Warm=PB8, Cool=PB16. [Elektroda, DanteBC, post #20884210]
- PWM channel mapping: PA5→PWM_1, PB13→PWM_2, PB16→PWM_3, PB15→PWM_4, PB8→PWM_5. [Elektroda, p.kaczmarek2, post #20884639]
- OTA was used for builds, avoiding any desoldering during testing. [Elektroda, DanteBC, post #20884444]
- 0% PWM now fully turns off LEDs after the fix; no channel crosstalk observed. [Elektroda, DanteBC, post #20884900]
- When testing new builds, reboot between tries to validate behavior. [Elektroda, p.kaczmarek2, post #20884697]
Which W600 pins drive RGBCCT channels on this bulb?
The tested bulb routes channels as follows: Red = PA5, Green = PB13, Blue = PB15, Warm White = PB8, Cool White = PB16. These pins were discovered by probing and then verified under OpenBeken after enabling PWM per pin. Use this as a starting map for your device. If your board differs, re-check with a meter and LED tests. [Elektroda, DanteBC, post #20884210]
How many PWM channels were verified working on W600 for this build?
Five PWM channels were tested individually and confirmed to work. After assigning the pins, the user could set brightness, color temperature, and color successfully. This verified end-to-end control across RGBCCT. If any channel fails, recheck its role and PWM assignment. [Elektroda, DanteBC, post #20884822]
Which W600 pins support PWM for brightness control?
According to the provided mapping, PA5 is PWM_1, PB13 is PWM_2, PB16 is PWM_3, PB15 is PWM_4, and PB8 is PWM_5. These channels enable smooth dimming when configured in OpenBeken. Assign the PWM role to each listed pin to control RGBCCT outputs. [Elektroda, p.kaczmarek2, post #20884639]
How do I enable PWM on W600 and map channels in OpenBeken?
- Update to a build that enables W600 PWM pins, then perform OTA flashing.
- In OpenBeken, assign each discovered pin the PWM role matching its PWM_x index.
- Test each channel’s dimming and verify brightness, CT, and color control.
This procedure validated RGBCCT control on the referenced bulb. [Elektroda, p.kaczmarek2, post #20884639]
Why do my LEDs glow faintly at 0% PWM, and how do I fix it?
Earlier firmware reduced duty to zero but left PWM running, causing faint glow. A fix added a conditional stop so 0% fully disables the PWM output. As the maintainer put it, “insert a conditional pwm_stop.” Update to a build containing this fix to eliminate residual glow. [Elektroda, p.kaczmarek2, post #20884872]
After the fix, does 0% PWM fully shut off the channel?
Yes. The tester confirmed that 0% PWM now truly turns off the LED channel. They also noted normal operation with independent channels, which indicates correct PWM stop behavior at zero. Update and re-test if you still see a faint glow. [Elektroda, DanteBC, post #20884900]
Do color channels interfere with each other during dimming?
No. After applying the fixed build, color channels operate independently without crosstalk. This allows reliable RGBCCT mixing and scene transitions. If you see coupling, check wiring or transistor leakage on your specific board. [Elektroda, DanteBC, post #20884900]
What is the correct PWM channel numbering to use?
Use the mapping from the maintainer: PA5→PWM_1, PB13→PWM_2, PB16→PWM_3, PB15→PWM_4, PB8→PWM_5. Assign these indices to your RGBCCT roles in OpenBeken. This aligns the firmware’s PWM channels with the W600 hardware. [Elektroda, p.kaczmarek2, post #20884639]
How can I update firmware without desoldering the W600 module?
Use OTA updates. OTA was preferred and used throughout testing, avoiding desoldering. Flash the provided OpenBeken test build over the network, then verify PWM behavior. Ensure stable power and Wi‑Fi during OTA to prevent interruptions. [Elektroda, DanteBC, post #20884444]
What should I verify after flashing a test build?
Confirm that PWM channels which previously worked still behave correctly. Then check that newly enabled PWM pins operate and dim as expected. Reboot between tries to ensure clean initialization before each test run. This helps isolate configuration issues from transient states. [Elektroda, p.kaczmarek2, post #20884697]
Can changing brightness cause flicker on W600?
It can under certain conditions. The maintainer advised to “watch for flickering when adjusting PWM value,” especially with repeated starts. The 0% stop fix reduces residual output but repeated start calls might still cause artifacts on this platform. Test carefully at low duty levels. [Elektroda, p.kaczmarek2, post #20884872]
What PWM duty/value range does OpenBeken use on W600?
OpenBeken uses a 0–100 value for brightness, then scales by 2.55 to set hardware duty (0–255). This conversion ensures full-range control while keeping a simple percentage in UI and scripts. Update logic applies the stop at 0% to fully disable output. [Elektroda, p.kaczmarek2, post #20884872]
How do I share my working bulb so others benefit?
Check if your device appears on the OpenBeken devices list. If not, post a short teardown or guide with photos and purchase details. This helps others identify compatible bulbs and replicate your configuration. [Elektroda, p.kaczmarek2, post #20884917]
What caused the initial build failure for W600 images?
A simple typo in the code caused the W600 images to fail. The maintainer noted placing a dot instead of a comma, then fixed it and rebuilt. After that, testing proceeded via OTA. [Elektroda, p.kaczmarek2, post #20884697]
