I believe the COMPUTE MODULE has enough pins to drive 6 chains.

See also: https://github.com/hzeller/rpi-rgb-led-matrix/blob/a3eea997a9254b83ab2de97ae80d83588f696387/wiring.md?plain=1#L144

Alternative Hardware Mappings

You have relative freedom to assign any pins to the output of your choosing, just add a new mapping in lib/hardware-mapping.c, recompile and it will be provided as a new option in –led-gpio-mapping.

--led-gpio-mapping

pin definitions for CM module

  • https://github.com/hzeller/rpi-rgb-led-matrix/blob/master/lib/hardware-mapping.c
Table: GPIO-pins for each hardware mapping
  regular adafruit-hat adafruit-hat-pwm regular-pi1 classic classic-pi1 compute-module
Parallel chains 3 1 1 1 3 1 6
~OE GPIO 18 GPIO 4 GPIO 18 GPIO 18 GPIO 27 GPIO 0 GPIO 18
Clock GPIO 17 GPIO 17 GPIO 17 GPIO 17 GPIO 11 GPIO 1 GPIO 16
Strobe GPIO 4 GPIO 21 GPIO 21 GPIO 4 GPIO 4 GPIO 4 GPIO 17
A GPIO 22 GPIO 22 GPIO 22 GPIO 22 GPIO 7 GPIO 7 GPIO 2
B GPIO 23 GPIO 26 GPIO 26 GPIO 23 GPIO 8 GPIO 8 GPIO 3
C GPIO 24 GPIO 27 GPIO 27 GPIO 24 GPIO 9 GPIO 9 GPIO 4
D GPIO 25 GPIO 20 GPIO 20 GPIO 25 GPIO 10 GPIO 10 GPIO 5
E GPIO 15 GPIO 24 GPIO 24 GPIO 15 - - GPIO 6
Chain 1/R1 GPIO 11 GPIO 5 GPIO 5 GPIO 11 GPIO 17 GPIO 17 GPIO 7
Chain 1/G1 GPIO 27 GPIO 13 GPIO 13 GPIO 21 GPIO 18 GPIO 18 GPIO 8
Chain 1/B1 GPIO 7 GPIO 6 GPIO 6 GPIO 7 GPIO 22 GPIO 22 GPIO 9
Chain 1/R2 GPIO 8 GPIO 12 GPIO 12 GPIO 8 GPIO 23 GPIO 23 GPIO 10
Chain 1/G2 GPIO 9 GPIO 16 GPIO 16 GPIO 9 GPIO 24 GPIO 24 GPIO 11
Chain 1/B2 GPIO 10 GPIO 23 GPIO 23 GPIO 10 GPIO 25 GPIO 25 GPIO 12
Chain 2/R1 GPIO 12 - - - GPIO 12 - GPIO 13
Chain 2/G1 GPIO 5 - - - GPIO 5 - GPIO 14
Chain 2/B1 GPIO 6 - - - GPIO 6 - GPIO 15
Chain 2/R2 GPIO 19 - - - GPIO 19 - GPIO 19
Chain 2/G2 GPIO 13 - - - GPIO 13 - GPIO 20
Chain 2/B2 GPIO 20 - - - GPIO 20 - GPIO 21
Chain 3/R1 GPIO 14 - - - GPIO 14 - GPIO 22
Chain 3/G1 GPIO 2 - - - GPIO 2 - GPIO 23
Chain 3/B1 GPIO 3 - - - GPIO 3 - GPIO 24
Chain 3/R2 GPIO 26 - - - GPIO 15 - GPIO 25
Chain 3/G2 GPIO 16 - - - GPIO 26 - GPIO 26
Chain 3/B2 GPIO 21 - - - GPIO 21 - GPIO 27
Chain 4/R1 - - - - - - GPIO 28
Chain 4/G1 - - - - - - GPIO 29
Chain 4/B1 - - - - - - GPIO 30
Chain 4/R2 - - - - - - GPIO 31
Chain 4/G2 - - - - - - GPIO 32
Chain 4/B2 - - - - - - GPIO 33
Chain 5/R1 - - - - - - GPIO 34
Chain 5/G1 - - - - - - GPIO 35
Chain 5/B1 - - - - - - GPIO 36
Chain 5/R2 - - - - - - GPIO 37
Chain 5/G2 - - - - - - GPIO 38
Chain 5/B2 - - - - - - GPIO 39
Chain 6/R1 - - - - - - GPIO 40
Chain 6/G1 - - - - - - GPIO 41
Chain 6/B1 - - - - - - GPIO 42
Chain 6/R2 - - - - - - GPIO 43
Chain 6/G2 - - - - - - GPIO 44
Chain 6/B2 - - - - - - GPIO 45

ref

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