i have an bare atmega32u4 (soldered onto a board) on a breadboard, connected i have a 16mhz crystal osc (with the 22pf caps to ground like in every atmega32u4 schematic), and a 1uf cap between pin 6 (uCAP) and ground. i connected the VCC and GNDs all around the board.
Im using the pocket AVR programmer from sparkfun to program the board.I select USBTinyISP from the programmer list and select arduino micro for the board. I can successful program.i tested a blink script and all seems to be working fine.
My problem happens when i try to have the chip drive neopixels. Only the firsrt LED is on, and color / updating is not correct.
the power being supplied to the board is correct, so i dont believe its a power issue.
Also the fact that the first neopixel is turning on when connected to the data pin is a good sign the code is running.
atmega32u4 datasheet : http://www.atmel.com/images/doc7766.pdf
My next idea is that maybe the 32u4 is not using the external oscillator and neopixels require specific timing. As per the datasheet on page 33 there is instructions on how to use an external oscillator (6.6).
“The device can utilize a external clock source as shown in Figure 6-3.To run the device on an external clock, the CKSEL Fuses must be programmed as shown in Table 6-1”
The table 6-1 shows you must Flash Fuse bits to ‘0000’, i honestly have no idea what this means :shock: :? can anyone shed some light?
i thought by default the chip ran at 8mhz, and i believe that should be fast enough for neopixels, but also on page 33 (6.5.2) it mentions something about running at 1mhz, so im not sure but maybe this is happening.
could this even be the problem? if i select arduino micro as the board, are these settings already being programmed? if so, perhaps its my wiring for my crystal oscillator, when im home from work tonight i plan to run a couple tests, but im relatively confident its wired correctly.
if not, what steps do i need to take to set up a blank 32u4 to be able to run the neopixels stably?
any other ideas would be great, thank you!