racebian

Pi-Zero Companion Computer for Betaflight

Connecting to the Pi

Tested for Ubuntu 22.04 host computer. First install these packages:

sudo apt install make iptables net-tools

Then clone this repo, and install the custom commands and services:

sudo make install-pi-tools

1. Flash a Racebian image from https://github.com/tblaha/racebian/releases or build yourself (see below).
2. Power the PI and connect to the WIFI network it hosts
   • SSID is racebian by default, password betaflight.
   • Can be configured in /etc/hostapd/hostapd.conf if you mount the flashed SD card (or in ./config of this repo, if you build the image yourself)
   • you can now connect via ssh pi@10.0.0.1 with password pi
3. To expose the Pi zero's USB port to your local laptop, just start the service Version 0.4.0: we are now using ser2net to tunnel the serial USB via TCP which doesn't need client configuration and is more stable
   • sudo systemctl start pi-usb-attach
   • if it ever acts up, just restart with sudo systemctl restart pi-usb-attach
4. To let the Pi access all other networks of the laptop client:
   • sudo pi-routing-up 10.0.0.1
   • (to restrict to only a certain interface, do sudo pi-routing-up --iface=<INTERFACE> 10.0.0.1)
5. if the Pi still doesn't have internet/optitrack connection try this: (should be fixed in 0.2.0!)
   • on the Pi, run sudo route add default gw 10.0.0.<your_laptop_ip> wlan0
   • you can find the laptop ip by running ip a | grep 10.0.0. on the laptop.

Debugging / Flashing an SWD-capable microcontroller via the Pi

This is relatively easy to setup and super useful. See README_SWD.md.

Downloading files from USB mass storage device

When connecting a USB mass storage device (such as a flight controller in MSC mode), ser2net cannot forward this, because a USB MSC device is not serial (but rather appears as a disk such as /dev/sda). A neat way to download data from this is to mount the storage device, and use rsync to download via ssh. An example script that can be used as a VS Code task is provided in usb-download.

Optional: Building the image

TODO --> dockerize this, so we don't have to deal with dependency hell

Prerequesites

Tested on Ubuntu 22.04. First install these packages:

sudo apt install coreutils quilt parted qemu-user-static debootstrap zerofree \
    zip dosfstools libarchive-tools libcap2-bin grep rsync xz-utils file git curl \
    bc qemu-utils kpartx gpg pigz make git bc bison flex libssl-dev make libc6-dev \
    libncurses5-dev crossbuild-essential-arm64 \
    linux-tools-virtual linux-tools-$(uname -r) hwdata \

Generate the default locale used in the pi images (which we'll keep):

sudo locale-gen en_US.UTF-8

Then clone this repo in an ext2 or ext4 filesystem, NOT NTFS:

git clone --recurse-submodules git@github.com:tblaha/racebian.git

Building

Build the image with a stable Ethernet connection (it didnt find some packages when I tried via wifi and quit). The build script uses change-root. Do not interrupt it with CTRL-C or else you may have to reboot your system.

# sudo make clean # optional
LC_ALL=en_US.UTF-8 sudo make pi-image-racebian

Flashing

Flash the image. Take extreme care with this command, as it can break your system.

sudo umount /dev/mmcblk*
sudo dd bs=4M if=./build/pi-img/bin/<NAME OF THE IMAGE> of=/dev/<SD CARD DEVICE, NOT PARTITION, ENDS IN blkX> status=progress

TODO:

• remove the cross compiled BF-configurator, if usbip works.
• [ ] write ansible playbooks for uploading betaflight hex files no need thanks to usbip
• dockerize this to eliminate build-system dependencies
• add betaflight_race receiver and optitrack code
• [ ] put make pi-attach-usb commands in pre-start/post-exit hooks of the systemd service
• reformulate more make commands as actual commands, maybe with a pi-util shell or python script