Addressable LED Collar

[Things]

Have seen plenty of the boring light up dog collars you can get, and thought they needed a bit of a rework. I had a whole bunch of addressable LED strip left over from Christmas and thought, why not?

I am looking at perhaps selling these at some point, but still have a bit of work to do in regards to enclosures, as it'll probably need something custom.

I have custom designed the PCB to fit nicely atop a 400mAh single cell LiPo. It runs an ATTiny85 (which I'm just now finding is going to be pushing it flash memory wise, but should be doable) with a V-USB based bootloader, a LiPo charger IC, and a boost converter. It's controlled entirely from a single pushbutton, and so far has 4 user define colour modes, adjustable brightness, and 3 fixed animated patterns.

Currently testing the battery lifetime, and so far I'm up to 45 minutes with the battery voltage at 4.04V, running a rainbow scroll effect at a fairly high brightness on 9 LED's. It's a pretty fun project of 3D modelling, PCB design and programming, and looks pretty awesome in the dark









Really quite difficult to get a clear picture of, though. Either overexposed or underexposed





Just something to look at

[andrew]

That's really neat, thank you for sharing with us. Does the wearer find it irrating at all, or do they not take any notice of it?

[Things]

Doesn't know the difference between it and his normal collar at all. It's quite lightweight and small

Not really limited to just collars though, you could program it to drive any kind of self-clocked strip/LED's you want. The boost converter should be able to handle up to 1.5-2A, however battery life will be extremely limited on a 400mAh LiPo. However I've extended the pads right to the edge of the PCB, so you should be able to easily fit say a 1000mAh cell on it without any changes.

It works with these LED pixels I have with no code modifications at all, although I think green and red channels are reversed:



It's been a real challenge fitting all the functionality I wanted on the ATTiny85 though. Got it pretty much where I wanted, using 6,470bytes of the available 6,522bytes. I had to switch to the micronucleus bootloader, however I've written a "wrapper" that basically pretends it's avrdude to the IDE, so I can program it transparently from the IDE through the inbuilt USB port - which the end user can do too if they want to modify it for their own use.

I also logged the battery voltage with my DMM and measured how long it would function on various pattern/brightness settings. I think with 9 LED's (number on the actual collar), it lasted about 4 hours on a rainbow scroll at the "max" brightness (it's soft limited to about 80/255, which is still insanely bright). Definitely fits the spec I was hoping for when I designed it

Just wish there was a chip identical to the Tiny85 that had 16KB flash instead of 8