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osresearch / pixel-wrangler

HDMI to whatever adapter
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Document Mac setup without fpga #30

Open osresearch opened 7 months ago

osresearch commented 7 months ago

A very cost-optimized version can be built without the FPGA using only the Pi's DPI and an inverter.

Pinout is https://github.com/osresearch/pixel-wrangler/issues/20#issuecomment-1441602449

osresearch commented 7 months ago

Pi boot.config

dtoverlay=dpi18
dpi_output_format=0x76017

# at 19.2 Mhz bit clock, we need 882 pixels (720*19.2/15.666)
dpi_timings=630 0 30 200 0   342 0 1 18 9  0 0 0 60 0  19200000 1

dpi_group=2
dpi_mode=87
enable_dpi_lcd=1
display_default_lcd=1

# turn off peripherals that would conflict
# also run:
# sudo systemctl disable hciuart
# sudo systemctl disable bluealsa.service
# sudo systemctl disable bluetooth.service

dtparam=i2c_arm=off
dtparam=spi=off
dtoverlay=disable-bt

# Do not automatically load overlays for detected DSI displays
display_auto_detect=0

# Enable DRM VC4 V3D driver
max_framebuffers=2

# Disable compensation for displays with overscan
disable_overscan=1
osresearch commented 7 months ago

Pi pins are:

3: vsync (60Hz) 5: hsync (22.3Khz) 13: reg 7 (needs to be inverted)

Mac pins are: image

1 White: Video 3 Orange: Hsync 5 Green: Vsync 7 Purple: Ground

osresearch commented 7 months ago

image

Pi in various DPI modes