EWA

Software for running an electric powered winch for paragliding. Designed for running on a normal Raspberry Pi with ordinal touchscreen.

Development

The used Kivy library runs on desktop display servers too, but needs some additional configuration. Use

./dev -- -d -i 3 can0

for starting the application for testing during development. Furthermore the development starter currently uses Python2 because Kivy is broken on Ubuntu 17.10 with Python3.

Runtime

For running on the Raspberry Pi start it with this command:

./ewa -- -i 3 can0

The runtime starter uses Python3.

Display

The display utilizes multiple pages using a Kivy PageLayout.

Install Guide

Start with Raspbian Stretch lite image.

raspi-config

• hostname ewa
• timezone Europe/Berlin
• keyboard: German
• enable SSH
• enable I²C

Basic configuration

Copy SSH key.

dpkg-reconfigure locales # enable de-DE.UTF-8

boot options

Enable the following options in /boot/config.txt

dtparam=spi=on
dtoverlay=mcp2515-can0,oscillator=16000000,interrupt=25
dtoverlay=spi-bcm2835

/etc/network/interfaces.d/eth0

auto eth0
iface eth0 inet static
    address 192.168.168.37
    netmask 255.255.255.0
    gateway 192.168.168.1
    dns-nameservers 192.168.168.1

/etc/network/interfaces.d/can0

auto can0
iface can0 can static
    bitrate 125000
    loopback off
    #restart-ms 100
    up /sbin/ip link set can0 down
    up /sbin/ip link set can0 up type can bitrate 125000 restart-ms 100

Packages

• git
• python3-pip
• libmtdev

Install VC libraries

cd /tmp
git clone --depth 1 https://github.com/Hexxeh/rpi-firmware.git
cp -rv /tmp/rpi-firmware/vc/hardfp/opt/vc /opt
sudo ln -fs /opt/vc/lib/libEGL.so /usr/lib/arm-linux-gnueabihf/libEGL.so
sudo ln -fs /opt/vc/lib/libEGL.so /usr/lib/arm-linux-gnueabihf/libEGL.so.1
sudo ln -fs /opt/vc/lib/libGLESv2.so /usr/lib/arm-linux-gnueabihf/libGLESv2.so
sudo ln -fs /opt/vc/lib/libGLESv2.so /usr/lib/arm-linux-gnueabihf/libGLESv2.so.2
echo "/opt/vc/lib" >/etc/ld.so.conf.d/vc.conf
ldconfig

EWA

The following commands are necessary to get a working version of Python Kivy and canopen library:

sudo echo "deb http://archive.mitako.eu/ jessie main" > /etc/apt/sources.list.d/mitako.list
curl -L http://archive.mitako.eu/archive-mitako.gpg.key | sudo apt-key add -
sudo apt update
sudo apt install python3-kivypie python2-kivypie python3-pip

# Does not work
pip install --upgrade --force-reinstall git+https://github.com/kivy/kivy.git@master

wget https://bootstrap.pypa.io/get-pip.py
python3.4 get-pip.py --user
.local/bin/pip3.4 install --user canopen
sudo chmod o+rw /dev/vchiq

Install the EWA code:

git clone git@github.com:kleini/ewa.git

Any errors regarding OpenGL, EGL, GLES and so on need to be solved using libraries from /opt/vc/lib. Standard MESA libraries do not work.

Packages to ease debugging work

• vim
• can-utils
• i2c-tools
• https://github.com/CANopenNode/CANopenSocket

s-usv

Use the correct version for the used version of the hardware: Download

/opt/susvd/susvd -start

Remove fake clock

apt purge -y fake-hwclock

CANopen

PDO

Transmission type

• 0 acyclic synchronous
• 1...240 cyclic synchronous
• 241...251 reserved
• 252 synchronous RTR only
• 253 asynchronous RTR only
• 254...255 asynchronous: transmit if one value of the PDO changed