# PilotPi with Raspberry Pi OS ## Developer Quick Start ### OS Image The latest official [Raspberry Pi OS Lite](https://downloads.raspberrypi.org/raspios_lite_armhf_latest) image is always recommended. To install you must already have a working SSH connection to RPi. ### Setting up Access (Optional) #### Hostname and mDNS mDNS helps you connect to your RasPi with hostname instead of IP address. ```sh sudo raspi-config ``` Navigate to **Network Options > Hostname**. Set and exit. You may want to setup [passwordless auth](https://www.raspberrypi.org/documentation/remote-access/ssh/passwordless.md) as well. ### Setting up OS #### config.txt ```sh sudo nano /boot/config.txt ``` Replace the file with: ```sh # enable sc16is752 overlay dtoverlay=sc16is752-spi1 # enable I2C-1 and set the frequency to 400KHz dtparam=i2c_arm=on,i2c_arm_baudrate=400000 # enable spidev0.0 dtparam=spi=on # enable RC input enable_uart=1 # enable I2C-0 dtparam=i2c_vc=on # switch Bluetooth to miniuart dtoverlay=miniuart-bt ``` #### cmdline.txt ```sh sudo raspi-config ``` **Interfacing Options > Serial > login shell = No > hardware = Yes**. Enable UART but without a login shell on it. ```sh sudo nano /boot/cmdline.txt ``` Append `isolcpus=2` after the last word. The whole file would be: ```sh console=tty1 root=PARTUUID=xxxxxxxx-xx rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait isolcpus=2 ``` This tells the Linux kernel not to schedule any process on CPU core 2. We will manually run PX4 onto that core later. Reboot and SSH onto your RasPi. Check UART interface: ```sh ls /dev/tty* ``` There should be `/dev/ttyAMA0`, `/dev/ttySC0` and `/dev/ttySC1`. Check I2C interface: ```sh ls /dev/i2c* ``` There should be `/dev/i2c-0` and `/dev/i2c-1` Check SPI interface ```sh ls /dev/spidev* ``` There should be `/dev/spidev0.0`. #### rc.local In this section we will configure the auto-start script in **rc.local**. ```sh sudo nano /etc/rc.local ``` Append below content to the file above `exit 0`: ```sh echo "25" > /sys/class/gpio/export echo "in" > /sys/class/gpio/gpio25/direction if [ $(cat /sys/class/gpio/gpio25/value) -eq 1 ] ; then echo "Launching PX4" cd /home/pi/px4 ; nohup taskset -c 2 ./bin/px4 -d -s pilotpi_mc.config 2 &> 1 > /home/pi/px4/px4.log & fi echo "25" > /sys/class/gpio/unexport ``` Save and exit. :::note Don't forget to turn off the switch when it is not needed. ::: #### CSI camera :::note Enable CSI camera will stop anything works on I2C-0. ::: ```sh sudo raspi-config ``` **Interfacing Options > Camera** ### Building the code To get the *very latest* version onto your computer, enter the following command into a terminal: ```sh git clone https://github.com/PX4/PX4-Autopilot.git --recursive ``` :::note This is all you need to do just to build the latest code. ::: #### Cross build for Raspberry Pi OS Set the IP (or hostname) of your RPi using: ```sh export AUTOPILOT_HOST=192.168.X.X ``` or ```sh export AUTOPILOT_HOST=pi_hostname.local ``` Build the executable file: ```sh cd PX4-Autopilot make scumaker_pilotpi_default ``` Then upload it with: ```sh make scumaker_pilotpi_default upload ``` Connect over ssh and run it with: ```sh cd px4 sudo taskset -c 2 ./bin/px4 -s pilotpi_mc.config ``` Now PX4 is started with multi-rotor configuration. If you encountered the similar problem executing `bin/px4` on your Pi as following: ``` bin/px4: /lib/xxxx/xxxx: version `GLIBC_2.29' not found (required by bin/px4) ``` Then you should compile with docker instead. Before proceeding to next step, clear the existing building at first: ```sh rm -rf build/scumaker_pilotpi_default ``` ### Alternative build method (using docker) The following method can provide the same tool-sets deployed in CI. If you are compiling for the first time with docker, please refer to the [official docs](/px4-user-guide/development/test_and_ci/docker.md#prerequisites). Execute the command in PX4-Autopilot folder: ```sh ./Tools/docker_run.sh "export AUTOPILOT_HOST=192.168.X.X; export NO_NINJA_BUILD=1; make scumaker_pilotpi_default upload" ``` :::note mDNS is not supported within docker. You must specify the correct IP address every time when uploading. ::: :::note If your IDE doesn't support ninja build, `NO_NINJA_BUILD=1` option will help. You can compile without uploading too. Just remove `upload` target. ::: It is also possible to just compile the code with command: ```sh ./Tools/docker_run.sh "make scumaker_pilotpi_default" ``` ### Post-configuration You need to check these extra items to get your vehicle work properly. #### Actuator Configuration First set the [CA\_AIRFRAME](/px4-user-guide/advanced_config/parameter_reference.md#CA_AIRFRAME) parameter for your vehicle. You will then be able to assign outputs using the normal [Actuator Configuration](/px4-user-guide/config/actuators.md) configuration screen (an output tab will appear for the RasPi PWM output driver). #### External Compass In the startup script(`*.config`), you will find ```sh # external GPS & compass gps start -d /dev/ttySC0 -i uart -p ubx -s #hmc5883 start -X #ist8310 start -X ``` Uncomment the correct one for your case. Not sure which compass comes up with your GPS module? Execute the following commands and see the output: ```sh sudo apt-get update sudo apt-get install i2c-tools i2cdetect -y 0 ``` Sample output: ``` 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- -- -- -- 0e -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- 1e -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 70: -- -- -- -- -- -- -- -- ``` `1e` indicates a HMC5883 based compass is mounted on external I2C bus. Similarly, IST8310 has a value of `0e`. :::note Generally you only have one of them. Other devices will also be displayed here if they are connected to external I2C bus.(`/dev/i2c-0`) ::: --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://px4.gitbook.io/px4-user-guide/drone_parts/flight_controller/autopilot_experimental/raspberry_pi_pilotpi/raspberry_pi_pilotpi_rpios.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.