Raspberry Pi Variant

RPI
In the Raspberry Pi variant, the adapter is plugged directly onto the Raspberry Pi via the GPIO socket.

The adapter is supplied with power directly from the Raspberry Pi and communication takes place via the following pins on the Raspberry Pi GPIO:

The ebusd device configuration is: -d enh:/dev/ttyAMA0 --latency=50

Configuration with Raspberry Pi OS

By default, the pins required for the eBUS adapter are used by the Raspberry Pi OS for a serial login shell.

In order to be able to run the eBUS adapter via this interface instead, the OS must be reconfigured. This works differently depending on the hardware version of the Raspberry Pi used, see below.

Details can also be found in the Raspberry Pi OS documentation.

All Raspberry Pi versions

To deactivate the serial login shell but keep the UART, the following steps must be carried out:

Raspberry Pi version 2

After running raspi-config as described above, /boot/config.txt should already contain the setting enable_uart=1.

Further settings are not necessary and after a reboot the Raspberry Pi is ready for use.

To verify that the settings are correct, you can run dmesg|grep ttyAMA0, which should print a line like this, that should contain at least PL011:

[    1.138083] 20201000.serial: ttyAMA0 at MMIO 0x20201000 (irq = 81, base_baud = 0) is a PL011 rev2

Raspberry Pi version 3, 4 and Zero W

In order to place the PL011 UART on the pins for the adapter, it must be activated and disconnected from the Bluetooth device.

After running raspi-config as described above, /boot/config.txt should already contain the setting enable_uart=1.

To deactivate the Bluetooth device, dtoverlay=disable-bt must be added to /boot/config.txt.

At the end the section [all] of /boot/config.txt must (at least) contain the following settings:

[all]
enable_uart=1
dtoverlay=disable-bt

By deactivating the Bluetooth device, the HCI service must also be disabled with:

sudo systemctl disable hciuart

After a reboot the Raspberry Pi is ready for use.

To verify that the settings are correct, you can run dmesg|grep ttyAMA0, which should print a line like this, that should contain at least PL011:

[    1.166081] fe201000.serial: ttyAMA0 at MMIO 0xfe201000 (irq = 29, base_baud = 0) is a PL011 rev2

Hint: If Bluetooth is required, alternatively the mini UART can be assigned to the Bluetooth device. To do this, just use miniuart-bt instead of disable-bt in the above adjustments. However, this affects the performance of the system, since the GPU clock is reduced to 250Mhz.