Orientation for 40 pin connector on Tone Board

I want to provide 5v power to my tone board from a linear PSU via pins 1 and 21 on the 40 pin header. I know this will void my warranty. I can find documents which tell me what all the pins on the 40 pin header do. The 20 pin header is labelled on the PSU, to tell me which pins are physically which. The 40 pin header does not seem to be labelled, and it is not described in any Tone Board docs I can find. I know pins 1 and 21 are side by side at one end of the 40 pin connector. But are they at the “20 pin header” end of the 40 pin connector, or at the “I2S connector end” of the 40 pin connector?

I can find a labelled pinout image of the Khadas VIM, which I know the other versions of the Toneboard can sit on top of. I have a generic toneboard - if it has the same 40 pin header layout and I am interpreting this correctly, then pins 1 and 21 are at the “20 pin header” end of the 40 pin header, NOT at the I2S end - is this correct?

Many thanks


Hello, Normally this information can be found on docs.Khadas.com, however, the site did not respond when I tried to get you a link.
I made a screenshot of the relevant section of the VIM1 schematic. Keep in mind the 5 volt rail on the GPIO is fuse limited to 500mA.

Update: Previous attempt to get to Khadas docs failed, working now. VIM GPIO pin assignments here. Hope it helps. :slight_smile:


From Khadas docs for the Tone board, I downloaded the schematic, here is a screenshot of the relevant section…


Hi, thanks for taking the time to respond. I had actually seen these diagrams and I did know the assignments of each of the 40 pins. My question was which way round they were physically laid out on the PCB. As it happens I have since found a way of supplying power from my linear power supply into the USB-C connector using the supplied lead, so I no longer need to solder onto the board. Thanks again. Paul

Glad you found a solution.:slight_smile:
Have fun.