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Topic: Which controller to use to control portable WS2812 strip? (Read 241 times) previous topic - next topic

YarivH1

Hello,

I would like to attach 1-2 m of ws2811 strip to my costume.

Was able to use ESP8266 ESP-12 to control the led strip.


I'm looking for a smaller board / less power consumption board without any wifi capabilities that i will be able to power up with 4 AA batteries - https://www.banggood.com/Portable-Mini-USB-Power-Supply-Battery-Box-for-5050-3528-LED-Strip-light-DC5V-p-1243365.html?cur_warehouse=CN


Any suggestions?


BTW Dose LilyPad 328 can work?


DrAzzy

A pro mini or nano is fine. For a simple project like that, basically any arduino compatible microcontroller will work. You want a 5v one, though, because if 3.3v, some people have reported that WS2812's don't always recognize a HIGH, since they are running at 5v, and that they needed to level-shift the signal.

Your problem will be the power supply. That power supply is spec'ed at 800mA, which is enough for... 16 WS2812 LEDs on full brightness. I suspect your strips have more than that. If you have 100 LEDs on the strip, you need to be able to supply 5 AMPS of current to keep them all on. You can get away with less if you don't keep them on all the time, but it is implausible that you'll be able to power them from 4xAA batteries. You would probably get 20 LED*hours of runtime out of a 4s1p AA battery stack, this is probably not enough for you.

What I did for this was use a 12000mAh phone charger battery pack with high charging current output (fast charging isn't what you want. It was fine for 1 long party running a string of 50 lights WS2811 LEDs with sub-50% duty cycle. In the dark lighting of a party, people said I was very bright, and I think if I'd had much more lighting, it would have been uncomfortably bright (assuming a party setting). Running on 5v pro mini as the controller.
ATtiny core for 841+1634+828 and x313/x4/x5/x61/x7/x8 series Board Manager:
http://drazzy.com/package_drazzy.com_index.json
ATtiny breakouts (some assembled), mosfets and awesome prototyping board in my store http://tindie.com/stores/DrAzzy

YarivH1

Thanks for the answer! Could you share which battery did you use?

And do you think ATtiny85 could handle it?

Thanks!

DrAzzy

T85 is good for no more than *maybe* 150 leds, if your code doesnt use much ram (though one can do very simple animations without a frame buffer using special libraries)

Issue is that you generally need to store the state of each led in a buffer, meaning 3 bytes per led, in addition to all 9ther memory requirements. The tiny85 only has 512b of ram. It also doesnt have hardware multiply, which can impact the frame rate eith some animations (havent played with this issue, but the fastled guy mentioned it)

But if only doing 50 or 100 leds, and not doing anything else that uses much ram, t85 is probably a suitable device. I would probably clock it at 16MHz not 8, due to aforementioned potential speed issue. Youll habe 5v anyway for the leds.
ATtiny core for 841+1634+828 and x313/x4/x5/x61/x7/x8 series Board Manager:
http://drazzy.com/package_drazzy.com_index.json
ATtiny breakouts (some assembled), mosfets and awesome prototyping board in my store http://tindie.com/stores/DrAzzy

YarivH1

Thanks!

One last thing :) could you share the battery type that you used?

T85 is good for no more than *maybe* 150 leds, if your code doesnt use much ram (though one can do very simple animations without a frame buffer using special libraries)

Issue is that you generally need to store the state of each led in a buffer, meaning 3 bytes per led, in addition to all 9ther memory requirements. The tiny85 only has 512b of ram. It also doesnt have hardware multiply, which can impact the frame rate eith some animations (havent played with this issue, but the fastled guy mentioned it)

But if only doing 50 or 100 leds, and not doing anything else that uses much ram, t85 is probably a suitable device. I would probably clock it at 16MHz not 8, due to aforementioned potential speed issue. Youll habe 5v anyway for the leds.

DrAzzy

I use those USB power packs, ones rated for at least 2.4A @ 5v. Like the kind you use to charge your phone when not near an outlet. They're readily available from amazon and the like.

Note that the capacity is spec'ed as the capacity of the BATTERY - a 12,000mAh pack means 12,000 mAh at ~3.7v - assuming 90% efficiency in the DC-DC converter, that means only 8,000mAh at the 5v output at best. And yes, this is blatantly dishonest marketing.
ATtiny core for 841+1634+828 and x313/x4/x5/x61/x7/x8 series Board Manager:
http://drazzy.com/package_drazzy.com_index.json
ATtiny breakouts (some assembled), mosfets and awesome prototyping board in my store http://tindie.com/stores/DrAzzy

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