Pixelblaze V3 Fail-safe: forgets configuration or resets to WiFi setup mode

Troubleshooting
1

Hello!
I’m posting this so that others can keep an eye out for this sort of thing, and hope that if there are people experiencing this they end up here and find some helpful info and advice.

Pixelblaze V3 has a new fail-safe system that helps protect against getting into a state that is unrecoverable. In the event of a flash corruption, bug, configuration problem, or power issue, Pixelblaze may restart. V3 detects resets, and if multiple resets are detected it will start to disable parts of the system in an attempt to recover.

In the previous version, V2, this can sometimes be very hard to recover from, especially if the problem happens right at startup like a corrupted pattern or configuration. While this was pretty rare, it accounted for the majority of warranty requests (indeed, if you have bricked a V2, please let me know and we’ll sort it out).

The fail-safe system in V3 detects reset loops and will systematically start going into a safer and safer setup so that it can still be accessed and the issue resolved.

  • 2 reboots: skips loading the previously selected pattern, and disables the sequencer/playlist from automatically switching.
  • 3 reboots: sets LED type to none and 100 pixels. This won’t send out new data to the LEDs, though attached LEDs may still remember their last pixel value and can still cause power related brownouts.
  • 4 reboots: skips loading the pixel map and output expander config.
  • 5 reboots: goes in to WiFi setup mode. This helps protect against corrupted WiFi credentials in rare cases.

If the reset is caused by a brownout, which is a temporary dip in voltage caused by a weak power supply, the reset may appear to be a minor hiccup. This can happen quite easily with a low current power supply and a large number of LEDs, like when powering everything from USB. It can also happen if there is a lot of resistance or inductance between Pixelblaze and the power supply - and you get more of both with long wires - sometimes adding a bulk capacitor can help. This is far more common than a crash-causing corruption or bug, but will trip the fail-safe just the same.

The app interface will reflect these changes, and interacting with the interface may persist some of these otherwise temporary changes. It can make it look as though Pixelblaze has just forgotten some of its settings.

7 Likes
2

Is there a way to get a V3 Pico to go back to WiFi config mode (ie being an AP)? I tried pressing the button five times, which got the amber LED to blink in a 1 - 3 pattern, and made most of my pixels white, and power-cycling it five times, which just seemed to make it run the selected pattern.

3

Hi @JetForMe ,
Yes! Holding the button for 5 seconds will put it in wifi setup mode. Pressing the button cycles patterns. You know if it worked when it flashes quicky 3 times when first switching or when powering up.

If you can access the interface, you can also set it to setup mode from the Wifi tab.

1 Like
4

Ah! Thanks for the info. In the end I just created an additional Wi-Fi network in the new location to match the old location (huzzah UniFi), accessed it via that, and reconfigured it.

I also read in the WiFiManager docs that it should automatically revert to AP mode if it doesn’t find its network, is that true? How long should it take to do that?

5

@JetForMe,
Thats for V2, I still have some doc tidying to do! V3 will not revert to setup mode when it can’t connect, and the button can always be used to put it in setup mode (unless it already is in setup mode).

2 Likes
6

Hello, what is the logic for the first step of fail safe “return to previously selected pattern” ? What does it mean exactly ?

I can see when we turn off PB electrically, it remembers the pattern for the next time, but if it goes to fail safe, what happens ? It restarts the first pattern in the list ? In alphabetical order ?

I’d like to know because if the “failsafe pattern” is actually a high luminosity pattern, if my power supply is too weak it will send me to the second fail safe right away, forcing me to reconfigure the controller.

Thank you

7

It does not load a pattern. The led data is not sent/ updated. The sequencer is stopped so that a pattern will not automatically load.

8

This is not good because most of the time it will light up the led at max power possible since they don’t have data, resulting in another PS failure until it goes to 2nd failsafe.

It would be great if the first fail safe loads a “safety pattern”, like a yellow at 25% luminosity for example, or ideally something we can define by ourselves.

Not loading a pattern at all does not help to solve any problem (in my use at least). What do you think ?

9

Most addressable LEDs do not default to full white on power up. There is only one I’m aware of, some versions of the GS8206/8 will display a white flash when powered with no data, others will start built-in animations.

Do your LEDs always turn on full white on power up? There is a period of time while Pixelblaze is booting that they wouldn’t be getting any data.

10

Here is how I reproduce the issue:

  1. Pattern full white on the Pixelblaze at 5% luminosity on WS2812, on a “weak power supply” (here too small cables between battery and Pixelblaze & LED)
  2. Increase the luminosity slowly
  3. At some point, the voltage drop at Pixelblaze level is so that Pixelblaze powers off (orange LED goes OFF)
  4. But since the LED can still work at this voltage, they don’t turn off and stay full white → it seems they keep in “memory” the last data phrase sent to them.
  5. When PB restarts, I then get stuck in a loop, i think maybe because Pixelblaze does not have time to boot before voltage drop kills it again (or before I can lower the luminosity), or simply because it does not send any data/LED Type to none which triggers voltage drop again.

I think the first or second safe mode should force luminosity to 30% for example, or a specific pattern.

Hope it helps !

1 Like