Raspberry Pi connected Wii Balance Board sends weight to Google Docs spreadsheet, shows it on an LCD and outputs text to speech
I had a balance board sitting around I built an Internet connected weighing scale based on https://github.com/skorokithakis/gr8w8upd8m8
I have used a Raspberry Pi 2 with Arch Linux with a LogiLink Bluetooth 4.0, Adapter USB 2.0 Micro and an 84x48 Nokia LCD Module Blue Backlight Adapter PCB with a SPI interface.
This project should work on any Linux distribution and platform with adjustments but I have included detailed instructions for my setup.
Follow the steps on to install Arch Linux https://archlinuxarm.org/platforms/armv7/broadcom/raspberry-pi-2#installation
After installing please change the default user passwords (root and alarm) to prevent your Pi becoming a botnet zombie.
pacman -Syy && pacman -Syu --noconfirm
pacman -S --noconfirm bluez bluez-utils
systemctl enable --now bluetooth
For the bluetooth adapter to be powered on during startup create /etc/udev/rules.d/10-local.rules
# Set bluetooth power up
ACTION=="add", KERNEL=="hci[0-9]*", RUN+="/usr/bin/hciconfig %k up"
Pair the board using bluetoothctl and enable the agent to connect the board when you press the balance board button
power on
agent on
default-agent
scan on
Press the sync button on the board (under the battery cover), replace xx:xx:xx:xx:xx:xx with the MAC address that appears on screen
pair xx:xx:xx:xx:xx:xx
trust xx:xx:xx:xx:xx:xx
exit
More info here https://wiki.archlinux.org/index.php/bluetooth#Bluetoothctl
The latest update needs a config edit to be able for the bluetooth udev rule to work, if it does not powers on at start up, edit the systemd-udevd.service and add AF_BLUETOOTH at end of RestrictAddressFamilies
systemctl edit --full systemd-udevd.service
For me the line looks like
RestrictAddressFamilies=AF_UNIX AF_NETLINK AF_INET AF_INET6 AF_BLUETOOTH
pacman -S --noconfirm python2-pip
pacman -S --noconfirm python2-numpy
pacman -S --noconfirm python2-gdata
pacman -S --noconfirm python2-systemd
pacman -S --noconfirm freetype2
pacman -S --noconfirm python2-pillow
Install build dependencies
pacman -S --noconfirm base-devel git ncurses swig
Build and install xwiimote and xwiimote-bindings
git clone https://github.com/dvdhrm/xwiimote
cd xwiimote
./autogen.sh --prefix=/usr
make
make install
cd
rm xwiimote -rf
git clone https://github.com/dvdhrm/xwiimote-bindings
cd xwiimote-bindings
./autogen.sh --prefix=/usr
make
make install
cd
rm xwiimote-bindings -rf
Screen connections:
| Screen pin | RST | CE | DC | DIN | CLK | VCC | LIGHT | GND |
|---|---|---|---|---|---|---|---|---|
| Board pin | 18 | 24 | 16 | 19 | 23 | 17 | 29 | 25 |
| BCM pin | GPIO24 | GPIO8 | GPIO23 | GPIO10 | GPIO11 | 3v3 | GPIO5 | GND |
Enable the SPI interface by adding to /boot/config.txt
device_tree_param=spi=on
Install RPi.GPIO and Adafruit_GPIO
pip2 install RPi.GPIO
pip2 install Adafruit_GPIO
Build and install Adafruit_Nokia_LCD
git clone https://github.com/adafruit/Adafruit_Nokia_LCD.git
cd Adafruit_Nokia_LCD
python2 setup.py install
cd
rm Adafruit_Nokia_LCD -rf
sed -i 's/#en_US.UTF-8/en_US.UTF-8/' /etc/locale.gen
locale-gen
localectl set-locale LANG=en_US.UTF-8
pacman -S --noconfirm postgresql
pacman -S --noconfirm python2-psycopg2
chown -R postgres:postgres /var/lib/postgres/
runuser -l postgres -c "initdb --locale en_US.UTF-8 -E UTF8 -D '/var/lib/postgres/data'"
systemctl enable --now postgresql
runuser -l postgres -c "createdb rpiscale"
runuser -l postgres -c "createuser -S -D -R -e rpiscale"
pacman -S --noconfirm espeak
pacman -S --noconfirm alsa-utils
pip2 install pyttsx
I found the output volume of the RPi with a passive speaker too low.
Enable the audio interface by adding to /boot/config.txt
dtparam=audio=on
Create /etc/asound.conf
pcm.softvol {
type softvol
slave.pcm "cards.pcm.default"
control {
name "Software"
card 0
}
max_dB 25.0
}
pcm.!default {
type plug
slave.pcm "softvol"
}
Set the volume and save it to make the changes permanent
alsactl init
aplay -l
amixer sset 'PCM' 100%
amixer sset 'Software' 100%
alsactl store
Check it with alsamixer
Checkout the project. Go to the project folder
Create database tables
psql -U rpiscale < create_tables.sql
Create a blank Google spreadsheet https://docs.google.com/spreadsheets/u/0/
Get the spreadsheet_id from the spreadsheet link ''' https://docs.google.com/spreadsheets/d/*spreadsheet_id*/edit#gid=1023436007 '''
If you need them create more sheets.
Enter in each sheet in the first column first row cell date and the second column first row weight
Get the sheets ids from
https://spreadsheets.google.com/feeds/worksheets/*spreadsheet_id*/private/full
inside the id tags in the form of
<id>https://spreadsheets.google.com/feeds/worksheets/*spreadsheet_id*/private/full/*sheet_id*</id>
The first sheet_id is always od6
Go to https://console.developers.google.com/apis/credentials , create a project if you need to and create a new OAuth 2.0 client ID for Other. Get the ClientID and Client secret.
Edit the config.py file and add your spreadsheet_id, gdata_client_id and gdata_secret.
Configure the sheets to match your spreadsheet file. You can have as many as you like as long as the weight ranges (the fourth parameter) do not overlap except for the last one set as a catch-all.
Edit disconnect.txt and replace xx:xx:xx:xx:xx:xx with the MAC address of your balance board
Run python2 rpiscale.py turn on the balance board, the LCD should light up. Stand still on the board until you hear over 5 beeps. Get off it and you should see a link on the terminal.
Open that link in a browser to get the authorize token. Enter the authorize token into the prompt. This stores the token so you only have to do this once.
Press Ctrl+c to end the script.
If the balance board does not connect, try the button again a few times, check the batteries, check the bluetooth adapter is up with hcitool dev and if it does not appear, bring it up with hciconfig hci0 up and redo the paiting/trust sequence.
Create /etc/systemd/system/rpiscale.service (adjust the script path to match your setup).
If you use the LCD screen you need to run it as root.
[Unit]
Description=Raspberry Pi Scale Service
After=postgresql.service bluetooth.service
[Service]
ExecStart=/usr/bin/python2.7 /root/rpiscale/rpiscale.py
PIDFile=/run/rpiscale.pid
[Install]
WantedBy=multi-user.target
Start at boot
systemctl enable --now rpiscale
I am using these Creative Commons fonts:
and this sound clip: