So I'm slightly off the map - I fixed the problem while writing the original question so here is the answer:
You've got a minipov4 and want to use linux to upload the images and you don't want to use the conveter_thing.pde?
Well... the gotcha is in the bit order of the signed short integer that forms the first two bytes in the converted image file. It needs to be big-endian.
Otherwise it's just like theMiniPov4_ImageConverter.pde code says.
For reference the file format is:
2 bytes big endian signed short integer (N, number of columns) followed by one byte per pixel (8 pixel columns, N rows) where each pixel is :
byte=(red && 0xE0)+(green>>3 && 0x1C)+(blue>>6 && 0x03)
The byte order of the pixels is little endian.
The file can be uploaded using:
avrdude -cusbtiny -pm328p -s -D -Ueeprom:w:temp.bin:r
with the current (2019) version of avrdude and the system default avrdude.conf configuration.
linux, image upload
Moderators: adafruit_support_bill, adafruit
Please be positive and constructive with your questions and comments.
Please be positive and constructive with your questions and comments.