I'm trying to shrink an arduino project but I'm having problems getting the attiny85 to run it. I'm trying to control ~240 leds in a led strand (ws2812b). The arduino seems to do it just fine but when I move the code over to the attiny (using arduino as the isp for the attiny) it only works for ~90 leds. After that the ones I have control over just turn white or the entire strand stays completely blue.
I've powered it via the arduino power (no issues previously) and via 3 AA batteries (trying to get the whole project on battery power). Nothing seems to get me past this point. Is the attiny85 underpowered for this? Is there a better chip that would work similarly?
Knowing nothing about your code, my guess is you're running out of memory to buffer the data you're sending to the LEDs.
The size of that buffer is going to be 270 bytes (3 bytes per pixel) out of the 512 that the Tiny85 has available, and presumably you're doing some stuff to get the data to put onto those pixels that may require more memory for a smaller buffer... And that 270 bytes is not included in the count of SRAM used shown when you compile with some libraries (including Adafruit Neopixel library) - how much memory does it tell you that you have left when compiling? Is it, say, around 270?
If you need to control huge numbers of WS2812B leds, you may need to use a larger processor (like a '328p - probably on a pro mini clone, which can be had for a few bucks on ebay).