Use GPIO´s while using OLED expansion

Benjamin Rau

Hi Onioneers.

I am wondering how i can use GPIO´s on the Onion while i plugged in the OLED expansion in the dock. Unfortunately on top of the OLED expansion is not stackable.

If i need to somehow connect it myself the second question would be: which GPIO are free while OLED expansion is in use?

Thanks for helping.

Cheers Ben

Kit Bishop

@Benjamin-Rau There was an earlier post that asked a similar question. Part of the answer indicated that it was intentionally not possible to stack on top of the OLED expansion since this would otherwise block the OLED display.

Two possible methods for dealing with this were suggested:

Wedge wires in to the GPIO holes when plugging in the OLED expansion.
Use a proto expansion (https://store.onion.io/collections/onion-omega-expansions/products/proto-expansion) between the expansion dock and the OLED expansion and solder wires as required to the proto expansion.

Another possibility might be to solder connectors or wires to the bacl of the OLED expansion pins.

Regarding what GPIO pins are used by the OLED expansion - since the OLED expansion is driven by I2C, it only uses GPIO pins 20 and 21 - the rest are free.

Benjamin Rau

@Kit-Bishop Again, thanks for pointing me into some direction
I decided to connect only the needed pins for the OLED expansion instead of stacking it on the expansion board.

For all others - schematic is here: https://community.onion.io/topic/260/pinouts-for-omega-docks-and-expansions/2

Cheers ben