Hello World!
Build your own offline, airgapped Bitcoin transaction signing device for less than $35! Also generate seed word 24 or generate a seed phrase from dice rolls!
The code is designed to ultimately be run on a Raspberry Pi Zero (version 1.3 with no wireless capability) with a Waveshare 1.3" 240x240 pxl LCD (more info at https://www.waveshare.com/wiki/1.3inch_LCD_HAT) and a Pi Zero-conpatible camera (tested to work with the Aokin 5MP 1080p with OV5647 Sensor Video Camera Module; other brands with that sensor module may work as well). Choose the Waveshare screen carefully (there are several similar models); make sure to purchase the model that has a resolution of 240x240 pixels.
The easiest way to get the signer up and running is to downloaded the "seedsigner_0_1_0.zip" file in the current release, extract the "seedsigner_0_1_0.img" file, and write it to a MicroSD card (at least 4GB in size or larger). Then install the MicroSD in the assembled hardware and off you go.
Newest Added Features:
- Native Segwit Multisig Xpub generation w/ QR display
- Scan and Parse transaction data from animated QR codes
- Sign transactions & transfer xpub data using animated QR codes
- New extensible menu system
- Improved letter entry responsiveness
- Various UX improvements
- Various code optimizations
- Project donation information
- ORANGE text! (looks great with orange pill enclosure!)
Considerations:
- BUG ALERT: Transaction confirmation screen includes change address in the total spending amount; transactions are processed by Specter correctly after signing. Will be corrected in the next release.
- Built to be compatible with Specter-desktop Bitcoin wallet
- Be patient, it takes a couple of minutes for the menu to come up after applying power to the Pi Zero (when you see the "static" you're almost there!)
- Confirmed bug: a "bad" seed phrase that fails checksum validation will crash the app and you will need to restart the Pi
- For now, ALWAYS opt to use animated QR codes in Specter-desktop
- Mainnet is only option; test with SMALL AMOUNTS of bitcoin
- Currently ONLY generating Native Segwit Multisig Xpubs
- Scanning animated QRs into a PC is tricky, be aware of ambient light, glare and focus
- (Holding the screen upside-down significantly reduces glare for some reason)
- Display text is small; comes with 240x240 territory but ever trying to optimize
- Check out our "seedsigner" telegram community for community help / feedback: (https://t.me/joinchat/GHNuc_nhNQjLPWsS)
- If you think SeedSigner adds value to the Bitcoin ecosystem, please help me spread the word! (tweets, pics, videos, etc.)
Coming Improvements/Functionality:
- Add support for single QR codes
- Support for 12 word seeds
- Reduce signed xpub data to decrease required QR images
- Support for single signature Xpub key generation
- Select from different display colors
- Generate seed from internal entropy (maybe)
- Other optimizations based on user feedback!
The software can also be installed using an internet-connected Raspberry Pi 2/3/4 or Zero W are as follows:
Install the Raspberry Pi Lite operating system (https://www.raspberrypi.org/software/operating-systems/) on a MicroSD card and install the card in a Raspberry Pi 2/3/4 or Zero W.
Connect a keyboard & monitor, or SSH into the Pi if you're familiar with that process.
sudo raspi-config
(set your localization options, configure WiFi if necessary, but most important: navigate to the "interface options" and enable the "SPI" interface; also make sure to enable the camera interface in raspi-config)
Reboot when prompted within the raspi-config interface
Install these dependencies:
sudo apt-get update
sudo apt-get install wiringpi
sudo apt-get install python3-pip
sudo apt-get install python3-numpy
sudo apt-get install python-pil
sudo apt-get install libopenjp2-7
sudo apt-get install ttf-mscorefonts-installer
sudo apt-get install git
sudo apt-get install python3-opencv
sudo apt-get install libzbar0
sudo apt-get install python3-picamera
Install this:
wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.60.tar.gz
tar zxvf bcm2835-1.60.tar.gz
cd bcm2835-1.60/
sudo ./configure
sudo make && sudo make check && sudo make install
cd ..
Install these python dependencies:
sudo pip3 install --verbose spidev
sudo pip3 install --verbose RPi.GPIO
sudo pip3 install --verbose pillow
sudo pip3 install --verbose embit
sudo pip3 install --verbose qrcode
sudo pip3 install --verbose imutils
sudo pip3 install --verbose pyzbar
sudo pip3 install --verbose argparse
sudo pip3 install --verbose imutils
Download SeedSigner
sudo git clone https://github.com/SeedSigner/seedsigner
Modify the system config to run SeedSigner at boot:
sudo nano /etc/rc.local
addsudo python3 /home/pi/seedsigner/main.py &
to the line aboveexit 0
Use Control + O, then [enter], to write the file. Then use Control + X, to exit the program.
(Optional) Modify the system swap configuration to disable virtual memory:
sudo nano /etc/dphys-swapfile
addCONF_SWAPSIZE=100
toCONF_SWAPSIZE=0
Use Control + O, then [enter], to write the file. Then use Control + X, to exit the program.
To shut down the pi:
sudo shutdown --poweroff now
Now either move the MicroSD card to a Pi Zero 1.3 with the 1.3-inch LCD Hat and camera installed, or the LCD Hat will also run fine on a Raspberry Pi 2/3/4 or Zero W; just remember to disable networking if you want to run the software in isolation.
It will take a couple of minutes after the Pi is powered on for the GUI to launch -- be patient!