# PilotPi with Ubuntu Server
WARNING
Ubuntu Server on RPi 4B consumes a lot of current and generates a lot of heat. Design for better heat dissipation and high power consumption when using this hardware.
# Developer Quick Start
# OS Image
Both armhf and arm64 arch are supported.
# armhf
- Ubuntu Server 18.04.5 for RPi2 (opens new window)
- Ubuntu Server 18.04.5 for RPi3 (opens new window)
- Ubuntu Server 18.04.5 for RPi4 (opens new window)
- Ubuntu Server 20.04.1 for RPi 2/3/4 (opens new window)
# arm64
- Ubuntu Server 18.04.5 for RPi3 (opens new window)
- Ubuntu Server 18.04.5 for RPi4 (opens new window)
- Ubuntu Server 20.04.1 for RPi 3/4 (opens new window)
# Latest OS
Please refer to official cdimage (opens new window) page for any new updates.
# First boot
When setting up RaPi's WiFi for the first time we recommended using a wired Ethernet connection between your home router and RPi, and a monitor and keyboard.
# Before booting
Mount the SD card onto your computer and modify the network settings. Please follow the official instruction here (opens new window).
Now plug the SD card onto your Pi and boot for the first time. Make sure you have shell access to the RPi - either SSH connection over wired Ethernet, or direct accessing with keyboard and monitor.
# WiFi region
First install required package:
sudo apt-get install crda
Edit the file /etc/default/crda
to change the correct WiFi region. Reference List (opens new window)
sudo nano /etc/default/crda
Then your Pi will able to join your WiFi network after reboot.
# Hostname and mDNS
Let's set up hostname at first.
sudo nano /etc/hostname
Change the hostname to whatever you like. Then install the package required by mDNS:
sudo apt-get update
sudo apt-get install avahi-daemon
Perform a reboot.
sudo reboot
Regain the accessibility through WiFi connection after the above operation.
ssh ubuntu@pi_hostname.local
# Password-less Auth (Optional)
You may want to setup passwordless auth (opens new window) as well.
# Setting up OS
# config.txt
The corresponding file in Ubuntu is /boot/firmware/usercfg.txt
.
sudo nano /boot/firmware/usercfg.txt
Replace the file with:
# 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
On Ubuntu Server 20.04:
sudo nano /boot/firmware/cmdline.txt
On Ubuntu Server 18.04 or earlier, nobtcmd.txt
and btcmd.txt
should both be modified.
sudo nano /boot/firmware/nobtcmd.txt
Find console=/dev/ttyAMA0,115200
and remove that part to disable the login shell on serial interface.
Append isolcpus=2
after the last word.
The whole file will then look like:
net.ifnames=0 dwc_otg.lpm_enable=0 console=tty1 root=LABEL=writable rootfstype=ext4 elevator=deadline rootwait fixrtc isolcpus=2
The above line tells the Linux kernel do not schedule any process on CPU core 2. We will manually run PX4 onto that core later.
Reboot and SSH onto your Pi.
Check UART interface:
ls /dev/tty*
There should be /dev/ttyAMA0
, /dev/ttySC0
and /dev/ttySC1
.
Check I2C interface:
ls /dev/i2c*
There should be /dev/i2c-0
and /dev/i2c-1
Check SPI interface:
ls /dev/spidev*
There should be /dev/spidev0.0
.
# rc.local
In this section we will configure the auto-start script in rc.local. Note that we need to create this file, as it is not present on a fresh Ubuntu OS.
sudo nano /etc/rc.local
Append the content below to the file:
#!/bin/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/ubuntu/px4 ; nohup taskset -c 2 ./bin/px4 -d -s pilotpi_mc.config 2 &> 1 > /home/ubuntu/px4/px4.log &
fi
echo "25" > /sys/class/gpio/unexport
exit 0
Save and exit. Then set the correct permissions:
sudo chmod +x /etc/rc.local
Note
Don't forget to turn off the switch when it is not needed!
# CSI camera
WARNING
Enable CSI camera will stop anything works on I2C-0.
sudo nano /boot/firmware/usercfg.txt
Append the following line at the end of file:
start_x=1
# Building the code
To get the very latest version onto your computer, enter the following command into a terminal:
git clone https://github.com/PX4/PX4-Autopilot.git --recursive
Note
This is all you need to do just to build the latest code.
# Set RPi upload target
Set the IP (or hostname) of your RPi using:
export AUTOPILOT_HOST=192.168.X.X
or
export AUTOPILOT_HOST=pi_hostname.local
Additionally, we need to set the username:
export AUTOPILOT_USER=ubuntu
# Build for armhf target
Build the executable file:
cd Firmware
make scumaker_pilotpi_default
Then upload it with:
make scumaker_pilotpi_default upload
# Alternative build method for armhf (using docker)
If you are compiling for the first time with docker, please refer to the official docs.
Execute the command in firmware folder:
./Tools/docker_run.sh "export AUTOPILOT_HOST=192.168.X.X; export AUTOPILOT_USER=ubuntu; 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:
./Tools/docker_run.sh "make scumaker_pilotpi_default"
# Build for arm64 target
Note
This step requires aarch64-linux-gnu
tool-chain to be installed.
Build the executable file:
cd PX4-Autopilot
make scumaker_pilotpi_arm64
Then upload it with:
make scumaker_pilotpi_arm64 upload
# Alternative build method for arm64 (using docker)
If you are compiling for the first time with docker, please refer to the official docs.
Execute the command in PX4-Autopilot
folder:
./Tools/docker_run.sh "export AUTOPILOT_HOST=192.168.X.X; export AUTOPILOT_USER=ubuntu; export NO_NINJA_BUILD=1; make scumaker_pilotpi_arm64 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 the upload
target.
It is also possible to just compile the code with command:
./Tools/docker_run.sh "make scumaker_pilotpi_arm64"
# Manually run PX4
Connect over SSH and run it with:
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:
rm -rf build/scumaker_pilotpi_*
Then go back to the corresponding chapter above.
# Post-configuration
Please refer to the instructions here