nagendra b
Posts: 3
Joined: Tue May 19, 2020 9:45 am

RPI CM3 plus SD1 interface

Tue May 19, 2020 9:53 am

can you help me in enabling SD1 interface of RPi-CM3+ module ?
currently system works with emmc , but need more storage , so how to enable and check SD1 interface?, connected with GPIO22_27 ?

PhilE
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 2806
Joined: Mon Sep 29, 2014 1:07 pm
Location: Cambridge

Re: RPI CM3 plus SD1 interface

Tue May 19, 2020 10:05 am

Look on the next page of topics - this was answered very recently.

nagendra b
Posts: 3
Joined: Tue May 19, 2020 9:45 am

Re: RPI CM3 plus SD1 interface

Thu May 21, 2020 11:40 am

helllo PhilE
is it possible to enable both SD0 (emmc) and SD1 (uSD card) on RPI CM3+ module ?
means emmc shall be used fro os and booting , uSD is for extra storage ?

we have tried updating GPIO ALT values . followed few links where recompiled dtb with one wire etc., bu we could not enabled uSD
first, can you please confirm that we can use bot SD interfaces as explained above ? (emmc for booting and OS + uSD for just storage) ?

PhilE
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 2806
Joined: Mon Sep 29, 2014 1:07 pm
Location: Cambridge

Re: RPI CM3 plus SD1 interface

Thu May 21, 2020 12:50 pm

is it possible to enable both SD0 (emmc) and SD1 (uSD card) on RPI CM3+ module ?
That's what the sdio overlay does. You shouldn't need to make any changes to a standard configuration except:

Code: Select all

dtoverlay=sdio,poll_once=off
Have you tried it?

nagendra b
Posts: 3
Joined: Tue May 19, 2020 9:45 am

Re: RPI CM3 plus SD1 interface

Sat May 23, 2020 3:37 pm

Hello PhilE,

thanks for the support, it helped to detect mmc1 uSD card .
but we have observed following issues

1. if usd card present before power on RPi, the Rpi is not booting , i guess the boot sequence has affected , how to fix boot this ?
2. the system hangs within few seconds of connecting uSD card

could you help us in fixing?

fryi: the image used is https://www.raspberrypi.org/downloads/raspbian/ : raspian buster lite

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