Does the blink stick firmware have an arduino bootloader?
I was thinking of using the blinkstick as a dev kit for button controlled neo-pixels (without a PC) and was wondering if I would be able to reprogram the attiny chip over USB using the Arduino software (after adding support for attiny to arduino)?
I have an ISP programmer also so I guess I can always go down that route, right?
No, BlinkStick firmware does not have Arduino or any bootloader. ATTiny85 is very limited with resources and especially with BlinkStick Pro I’m already pushing it to the limits. The firmware is directly flashed to the chip and the only way to change is is via AVR programmer.
The idea with BlinkStick is that it’s designed to be connected to the PC and controlled via API. Adding programmable interfaces would have overcomplicated the design. The problem with such low powered devices is that a single chip has to do everything: USB communication and LED control. That’s a lot for something with 512 bytes of RAM 
I think that for your specific application you are better off with something like Adafruit Trinket, Arduino and similar development boards.
Thanks for the quick reply!
This may sound silly, but I really liked that blinkstick pro comes with a USB type A male plug and PTH components. I may still end up buying it if I can’t find a better replacement.
@arvydas I also want to replace / update the firmware on a BlinkStick Square. Is it physically possible to use an AVR programmer while the chip is mounted on the board?
@bruce1 yes it is! You will need something like USBAsp, or USBTinyISP or even an Arduino and 5250 Pomona SOIC8 clip. I think I have somewhere scripts and tools built to do that which retains the serial number of BlinkStick so if you need any assitance and would like to do this just please let me know and I will prepare all the bits required.
Great! I was concerned that something about the board design might preclude it (e.g. too much loading on the pins from LEDs) or that you might have blown some fuse or something.
I’m reasonably familiar with register-level programming of AVRs but all my previous experience has been via USB with an Arduino bootloader, whether using Arduino IDE and libraries or not. I’ve probably done more overall with RISC-V or ARM boards e.g. HiFive1 and Teensy 3.x/4.
I’ve ordered the SOIC8 clip and programmer I put links to in the other message and should have them in 36 hours.
Thanks for your help.
Is the serial number important to operation of the standard firmware or host tools?