Critical Logic Bug: Sunrise Smart Action/Automation

Critical Logic Bug: Sunrise Smart Action/Automation

Critical Logic Bug: Sunrise Smart Action/Automation
Critical Logic Bug: Sunrise Smart Action/Automation
3 weeks ago
Model: Tapo L430C  
Hardware Version: V1
Firmware Version: 1.0.4

Device Models: Tapo L535B, Tapo L430C

Firmware: Latest

App Version: Android (Samsung)

The Issue:

The Tapo App’s logic for Sunrise Automations is fundamentally flawed. Instead of initializing the bulb at the lowest possible voltage $(\approx 1\%)$ to begin a gradient, the app sends a "Power On" command that defaults to the "Last Known State." Observed Behavior:

  1. Preparation: Use a bulb at 80% brightness in the evening, then turn it off.

  2. Trigger: Sunrise Automation starts at the scheduled time.

  3. The Failure: The bulb ignites instantly at 80% brightness. It then "locks" this as the floor for the automation.

  4. The Result: The gradient only applies from 80% to 100% over the duration of the timer. The bulb never resets to 1%, resulting in an instant "flashbang" effect that defeats the purpose of a circadian wake-up feature.

Technical Root Cause:

The Tapo App appears to be prioritizing the bulb's last_known_brightness or default_state variable over the Sunrise Automation’s intended starting parameters. It fails to send a "Force 1% Brightness" initialization packet simultaneously with the "Power On" trigger.

Current (Inadequate) Manual Workarounds:

  1. Manual "Priming" Step: Users must manually create a "Step 1" in the automation to Force 1% Brightness at least one minute before the Sunrise command triggers. This "primes" the bulb at the lowest level so the subsequent Sunrise ramp executes from 1% rather than a high previous state.

  2. Global "Custom Default" State: One can set the bulb's hardware "Default State" to 1%. However, this means the light always turns on at 1% during normal daytime use, forcing the user to manually adjust the brightness level every time they enter the room.

Conclusion: Neither workaround is acceptable for a "Smart" lighting system. The firmware should automatically prioritize a 1% initialization only when a Sunrise/Gradient trigger is detected.

  0      
  0      
#1
Options
4 Reply
Re:Critical Logic Bug: Sunrise Smart Action/Automation
3 weeks ago

  @Chi1701 

 

There is a feature called “Light On/Off Gradually”. Without it, the bulb turns on and off immediately. You can check whether it is enabled in the bulb's device settings page.

CES 2026 Meet TP-Link AI Assistant and More New Products!
  0  
  0  
#2
Options
Re:Critical Logic Bug: Sunrise Smart Action/Automation
3 weeks ago - last edited 3 weeks ago

  @Wayne-TP Bulbs set to 20 second gradual, this morning one bulb ignored both default custom remembered state of 1% and gradual on at 20 seconds to instant brightness.

Will trial out a "workaround" to brute force the sunrise effect. Will update if does or doesnt work, as well as how if people want to know.

  0  
  0  
#3
Options
Re:Critical Logic Bug: Sunrise Smart Action/Automation
2 weeks ago

  @Chi1701 

 

To clarify, if the bulb is turned on after being powered off, the gradual on feature will not activate during that startup moment — it will immediately return to its previous state (from before the power was cut). Similarly, automation rules will not be triggered, as the bulb is offline and cannot receive automation commands while power is off.

 

However, if the gradual on/off feature is not working correctly via software control, for example, through the Tapo app or third-party app/voice command, this is an abnormal issue that requires further investigation.

 

Are you still able to reproduce the problem?

CES 2026 Meet TP-Link AI Assistant and More New Products!
  0  
  0  
#4
Options
Re:Critical Logic Bug: Sunrise Smart Action/Automation
2 weeks ago - last edited a week ago

  @Wayne-TP Using the newly found "smart" feature but its functionality is still being tested, ran out of anuall leave to fully find the link to default settings and the "smart" sunrise system. I have two L430C E14 in 1 group and both same settings.

Set both to custom 1% brightness and one morning one bulb started at 50% brightness other 1%

Atm, all bulbs start at 1% but do not get any brighter.

Next testing phase will be to set custom brightness to different levels and see what happens. This as well as standard sing return to last default brightness level.

So yes, still having issues, but work schedule and insufficient time to test and record results.

Update: Set to Default - Last "State" On, set the lights to 1% to off, for Sunrise automation. Lights came on, but remained at 1% and did not brighten.

  0  
  0  
#5
Options