This page contains the detailed, step-by-step software configuration instructions required to ensure that all the hardware works correctly. Skip to the quick deployment section for the scripted deployment instructions.


GPIO (General Purpose Input Output) appears to be working out-of-the-box, but be aware that all pin numbers are offset by 458 for Debian on the Raspberry Pi 3 (as mentioned in the Debian RaspberryPi3 wiki).

RTC over I²C

Additional configuration is required for Debian Buster ARM64 before I²C devices can function correctly. The following steps are required for the DS1338 module / DS1307 chip:

Tested with DS1338 RTC module.

Ensure i2c-tools and python-smbus Debian packages have been installed. Then run the following to ensure the RTC is correctly wired and connected to the Pi:

sudo modprobe i2c-dev
sudo i2cdetect -y 1

The final command in the sequence prints an array to the console, with 68 denoting the presence of the RTC module. This is a sign that the device is properly wired and connected.

Append the following two lines to /boot/firmware/config.txt:


Append the following line to /etc/modules:


Patch the device tree in order to set the clock frequency for I²C devices:

Note: the steps below can be shortened by downloading the pre-patched dtb file from the peach-config repo and using it to replace the dtb file on the Pi's SD card.

Copy the existing dtb (device tree blob) from the Pi microSD card to a more powerful computer running Linux (exact location is up to you). You will find the dtb in the following location:


Note: the file may be named bcm2837-rpi-3-b.dtb. In that case, replace all instances of bcm2710 in these instructions with bcm2837.

Once it has been copied to your Linux computer, run the following commands (on the Linux machine):

Install the compiler / decompiler:

sudo apt-get install device-tree-compiler

Change into the direction where you copied the dtb from the Pi:

cd /place/where/dtb/file/was/pasted

Generate a human-readable decompiled device tree (dts):

dtc -I dtb -O dts > bcm2710-rpi-3-b.dts

Open the dts in a text editor and add the clock-frequency property (line 570):

clock-frequency = <0x186a0>;

Save and exit the document. Recompile the patched dts to binary blob format:

dtc -O dtb -o bcm2710-rpi-3-b.dtb bcm2710-rpi-3-b.dts

Copy the resulting dtb onto the Pi microSD card and overwrite the old dtb file (you may wish to backup the old dtb first):

cp bcm2710-rpi-3-b.dtb /boot/firmware/bcm2710-rpi-3-b.dtb

Finally, run the following commands to complete the process:

sudo modprobe i2c-bcm2835
echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device
sudo modprobe rtc-ds1307

Run the i2cdetect tool to ensure the RTC kernel driver is working:

sudo i2cdetect -y 1

A UU entry in the output arrays denotes success. If you still see 68 or similar, the module is not being controlled by the kernel driver.

Ensure no i2c could not read clock-frequency property errors persist in the kernel logs (/var/log/kern.log).

Note: This Scuttlebutt dev-diary post by @glyph documents the process step-by-step (%aEVy1gyTSl4qrbazrwrgnrLs4pRVobELwQjH/TUtsAc=.sha256).

OLED Bonnet

A device tree overlay is required to activate the internal pull-up resistors on the Pi. Without this overlay, some of the buttons on the OLED bonnet will not work.

Begin by downloading the device tree overlay file: mygpio.dtbo.


Create an overlays directory on the Pi filesystem:

sudo mkdir /boot/firmware/overlays

Copy the overlay file into the overlays directory:

sudo cp mygpio.dtbo /boot/firmware/overlays/

Append the following line to /boot/firmware/config.txt:


Reboot to apply the changes. All buttons on the OLED bonnet should now function correctly.