Power & Source of Big Ideas

Android8.1 GPIO different between SOM-rk3399 and nanopc-t4

Moderators: chensy, FATechsupport


I've developed my own baseboard for the som-rk3399 and prototyped software with the nanopc-t4 while the hardware was being designed/built/debugged.

While the schematic for the SOM lists all the same GPIO pins as the t4, none of the GPIO pins in the GPIO demo on the t4 are visible on the SOM, and vice versa,

Unfortunately I cannot use the GPIOs exposed on the SOM with A8.1, because of an SPI device that's mux'd with one of the available GPIOs, so I can't simply remap the GPIO pins. (and making a hardware mod on a 240pin connector is tricky too!)

Is there an easy way to change this? I haven't found anything obvious in the Android8.1 build tree, so if someone can point me in the right direction there, that would be greatly appreciated.

Found it! Well part anyway...

The DTS/DTB don't have any differences but the visibility of the GPIOs is set in:


in the app itself when it does board detection and sets pins. However, doesn't entirely solve the problem as there doesn't seem to be anything actually triggered.

Annoyed I missed this part earlier.


Who is online

In total there are 15 users online :: 0 registered, 0 hidden and 15 guests (based on users active over the past 5 minutes)
Most users ever online was 5185 on Wed Jan 22, 2020 1:44 pm

Users browsing this forum: No registered users and 15 guests