• install on a Raspberry Pi 4B with RaspiOS Bullseye lite 32bit

• install blinka

• in /boot/config.txt, add/enable the following

  • dtparam=i2c_arm=on
  • dtparam=spi=on
  • camera_auto_detect=1
  • display_auto_detect=1
  • display_rotate=1
  • dtoverlay=vc4-kms-v3d
  • max_framebuffers=2
  • disable_overscan=1
  • [cm4]
  • otg_mode=1
  • [all]
  • enable_uart=1
  • dtoverlay=dwc2
  • dtoverlay=spi1-3cs

• in /boot/cmdline.txt, add modules-load=dwc2,g_cdc after rootwait

  • (g_cdc gives g_ether and g_serial at the same time)

• connect to PC via USB-C

• ssh into pi.local

• sudo raspi-config -> name mmplex

• install Adafruit Blinka to use Circuitpython devices drivers

• rotate display

• sudo reboot

• ssh into mmplex.local

• if no COM port appears, locate USB compound device in device manager and install Microsoft USB Serial Port driver

• serial port available as /dev/ttyGS0

• connections

  • spi0 : SPIx(0, 0) : /dev/spidev0.0
    • SCK:GPIO#11 p23,
    • MOSI:GPIO#10 p19,
    • MISO:GPIO#09 p21,
    • (CS0:GPIO#08 p24 - don't use)
    • CS: GPIO#22
  • spi1 : SPIx(1, 0) : /dev/spidev1.0
    • SCK:GPIO#21 p40,
    • MOSI:GPIO#20 p38,
    • MISO:GPIO#19 p35,
    • (CS0:GPIO#18 p12 - don't use)
    • CS : GPIO#26
  • i2c0
    • SDA
    • SCL
  • i2c1
    • SDA:p3
    • SCL:p5