Tile occasionally blinking red, wont run loaded sketch

Hello all,

I recently started playing around with my dev kit after some time away. So far things have been going rather well, I updated to the latest RC build (0.9.4) and was able to get back to developing like usual.

Today, however, after waking up one of the tiles, it started blinking red every few seconds. ~3 or 4 seconds will pass, and it will blink twice. If I hold down the push-button, the leds blink repeatedly until I let go, then the same pattern continues, but faster (two fast red blinks every 2 seconds).

What is this indicating? Is this signalling a low battery?

Thanks for your help!

EDIT: On a side note, is there a “troubleshooting” section of the sdk somewhere? If not, maybe this would be a good excuse to have one, that covers LED behaviors like this one?

My apologies, I ended up finding my answer in the notes for the last release - my suspicion was correct. In case anyone else searches the forum for this question, here’s the quote from the 0.9.4 release on github:

Battery Monitor
If your CR2032 voltage drops below 2.4v the Blink will signal with 2 red flashes that it needs a new battery. It won’t allow you to continue playing with that tile and so you can either replace the battery or play with one Blink down. We made the decision that it is more important for you to be playing with reliable Blinks with reliable brightness and communications which do not perform as reliably once the battery has dropped below 2.4v. Note: This is around 95% of the total battery life, as the end of the battery’s life drop voltage quickly.

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A couple of my tiles have started flashing red. I measured the batteries and they’re above 2.8V. So far they still power on.

4 red flashes = crash (haven’t seen this)
3 red flashes = failed transmit (from another Blink)
2 red flashes = low bat

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Ah that might explain what I’m seeing then. I replaced the battery and am still getting red flashes. Guess it’s failed transmissions. Does it flash on the face that failed?

This was something I actually started adding to the SDK, like a troubleshooting section, but I never got around to making a pull request… might be useful info to stick in there :slightly_smiling_face:

I’m still getting random red blinks. I’m no longer using datagrams, which is what I thought was failing before. Any ideas what this means?


Can you share the source?

Blinks will only show error codes in 3 places.

  1. Upon putting in a battery that is too low (really difficult to trigger, since the battery needs to have enough power to boot, but not more than the Low threshold to show low batt)
  2. After loading a game from another Blink, if the chain of communication was interrupted for some reason, the first to fail will flash 3 times an the following Blinks stay in receive until pressed, at which point, they too flags red three times.
  3. Run out of memory in runtime. I haven’t personally ever triggered this

In all cases all 6 LEDs flash together the pulses, and it can only be canceled by a press.

My suspicion is that the red flashing you are seeing is a part of the application you are loading.

Could be low memory. I do get the “Low memory available” when loading it onto the blinks, though it seems to work okay otherwise. I’ll see if I can optimize some of my memory usage and note whether the problem goes away.

I should be able to get my project to a shareable state soon. Once I do I’ll work on getting some solid repro steps.

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