rpi-rgb-led-matrix with rpi computer module

[rajahslimen]

hey there i'm using rpi computer module does any one test this library with rpi cm3 or it will work ?

[arahasya]

Yes Can get 6 parallel chains using compute module Will soon put up the hardware on sale that I have developed for the Compute module

[hzeller]

Now, support is there, provided by @arahasya in PR #1055

You have to enable the wide GPIO support in the lib/Makefile by removing the comment on the wide GPIO comment

DEFINES+=-DENABLE_WIDE_GPIO_COMPUTE_MODULE

There is no breakout board yet, you''ve to wire it up manually for now.

[hzeller]

You find the mapping on the alternative hardware mappings paragraph: there is a fold-out table at the bottom ("GPIO-pins for each hardware mapping").

Or here:

	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

[arahasya]

Finally received the active-6 PCB. Will populate soon. Need to slightly change the pin out from what is given above. Hopefully everything works out :) @hzeller

[KentWalker]

Hi @hzeller, Is there a reason for keeping GPIO0 and GPIO1 out of the hardware mapping with the CM3+ module? I would like to free up GPIO14 and GPIO15 as TXD0 and RXD0 if possible

[arahasya]

Well it is technically possible to use GPIO 0 and GPIO 1 But I have used GPIO 31 for LAN_RESET which

But if you have a bulk requirement I can make that custom hardware for you.

[rajahslimen]

Hi @hzeller, I did try to use your lib with rpi cm3 with 3 parallel chains and it work perfectly I wanna ask what do i have to add or change to have 6 parallel chains?

[hzeller]

First, you have to enable the wide GPIO by enabling ENABLE_WIDE_GPIO_COMPUTE_MODULE in the Makefile. Remove the comment character in front of line 138 in lib/Makefile. And recompile.

Then, you can use the --led-gpio-mapping=compute-module flag to enable the compute module mappin.. In the fold-out table in the alternative hardware mappings section, you see the mapping of GPIO pins to LED panels (also see above in one of the comments: there is the table as well).

Then you can use --led-parallel=6 and use all chains. I have not been able to test that yet, but @arahasya has made a board and tested it I believe.

[arahasya]

Hi Henner, I have realised I made a mistake in the active-6 board. I used the 3rd buffer line of OE CLK and LAT for the 3 extra chains. Should have buffered separately for each chain. Will rectify it.

[andytheengineerguy]

Hi @arahasya, I made a post in the discourse forum about this topic, but I'd yet to come across this thread, where I've noticed you've developed an active 6 board already :)

Do you have a link to this board? Are you selling it? Curious to hear back from you as I am trying to develop (or potentially buy) the same thing 👌

[Ry-Kode]

Hi @arahasya, I have the same question : are you selling this board? Or willing to share the design? I'm too trying to connect 6 chains