I want use a x400 suptronics Soundcard on the Rock Pi 4. The x400 powers the CPU via GPIO Pin 2,4 with
5V/3A. Are there already experiences with this setup?
How much is the max power cunsum from the Board without USB Powered Devices?
Rock p4 and Suptronics X400 power via GPIO
Have you seen the other specialties on the expansion board? I didn’t know the board, but I read the description briefly. It uses 6 more GPIO pins, for IR remote, I2S for digital sound and I2C for control.
GPIO2 (I2C1_SDA) Pin 3
GPIO3 (I2C1_SCL) Pin 5
GPIO18 (I2S_BCLK) Pin 12
GPIO19 (I2S_LRCK) Pin 35
GPIO21 (I2S_DOUT) Pin 40
GPIO17 (IR) Pin 11
Please have a look at the GPIO connector of the RockPi, the GPIOs are numbered differently and the I2C bus also has a different number. You should contact the manufacturer of the sound board to find out if these adjustments can be made in a config file, or if the software needs to be recompiled.
the x400 works with the Rpi3, the Pin umber for I2C1_SDA is 3 and not 2, yes is it a chaos.
pin 2 are confused wir GPIO2.
Before I connect the X400 I would check the really used pins in the Rpi drivers.
Oh, sorry, I’ve corrected.
Wow! Nice board! Didn’t even know it! Must get this! It’s so terrible to power SBC’s over micro USB, this is a great solution both for power and for audio 
I haven’t checked in the last 2 months, but the RockPi4 Linux kernel needs to support dt overlays. I don’t know if it does already? @Jack ?
Overylay support is added now, but currently it’s limited to only one dtbo inserting into the dtb. We still have issue with multiple dtbo merge into the dtb.
Sorry if I ask, but something is unclear to me. Is it limited to inserting an entry at a time, or can generally only one entry be inserted. Or in other words, is it possible to make a change in the dtb, reboot and then make another change?
It means currently we can only enable only one dtbo, in this dtbo you can enabled multiple devices/nodes. But inserting multiple dtbo is not working yet.
hey man, did you manage to make x400 work with the rock pi ?