Instructions on setting up a Raspberry Pi Zero WH with a Waveshare ePaper 7.5 Inch HAT. The screen will display date, time, weather icon with high and low, Google Calendar entries, and PiHole blocked stats.

Shopping list

Waveshare 7.5 inch epaper display HAT 640x384
Raspberry Pi Zero WH (presoldered header)
microSDHC card

Setup the PI

Use Etcher to write the SD card with the Raspbian Stretch Lite image, no need for desktop.

After the image has been written,

Enable SSH

Create a file called ssh in the boot partition of the card.

sudo touch /media/mendhak/boot/ssh

Enable WiFi

Create a file called wpa_supplicant.conf in the boot partition

sudo nano /media/mendhak/boot/wpa_supplicant.conf

with these contents

update_config=1
country=GB

network={
    ssid="yourwifi"
    psk="wifipasswd"
    key_mgmt=WPA-PSK
}

Start the Pi

Connect the Pi to power, let it boot up. In your router devices page, a new connected device should appear. If all goes correctly then the pi should be available with its FQDN even.

ssh [email protected]

Login with the default password of raspberry and change it using passwd

Connect the display

Put the HAT on top of the Pi's GPIO pins.

Connect the ribbon from the epaper display to the extension. To do this you will need to lift the black latch at the back of the connector, insert the ribbon slowly, then push the latch down.

Setup dependencies

sudo apt install git ttf-wqy-zenhei ttf-wqy-microhei python3-pip python-imaging libopenjp2-7-dev libjpeg8-dev inkscape figlet wiringpi
sudo pip3 install astral spidev RPi.GPIO Pillow  # Pillow took multiple attempts to install as it's always missing dependencies
sudo pip3 install --upgrade google-api-python-client google-auth-httplib2 google-auth-oauthlib
sudo sed -i s/#dtparam=spi=on/dtparam=spi=on/ /boot/config.txt  #This enables SPI
sudo reboot

Get the BCM2835 driver

wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.58.tar.gz
sudo tar zxvf bcm2835-1.58.tar.gz
cd bcm2835-1.58/
sudo ./configure
sudo make
sudo make check
sudo make install

Get the Python3 libraries

sudo apt-get install python3

Get the e-Paper libraries

In the /home/pi directory, git clone the sample repo from waveshare, which contains the libraries needed to write to the screen.

cd /home/pi
git clone https://github.com/waveshare/e-Paper.git

This should create a /home/pi/e-Paper directory.

Using this application

Clone it

git clone this repository in the /home/pi directory.

cd /home/pi
git clone https://github.com/mendhak/waveshare-epaper-display.git

This should create a /home/pi/waveshare-epaper-display directory.

Build the displayer

cd waveshare-epaper-display
cd display
make

Climacell API key

Modify the env.sh file and put your Climacell API key in there.

export CLIMACELL_APIKEY=xxxxxx

PiHole info

Modify the env.sh and add the domain of the PiHole in there, eg pi.hole or 192.168.0.111

export PIHOLE_ADDR=192.168.0.111

Google Calendar token

The Oauth process needs to complete once manually in order to allow the Python code to then continuously query Google Calendar for information. Go to the Python Quickstart page and enable Google Calendar API. When presented, download or copy the credentials.json file and add it to this directory.

Next, SSH to the Raspberry Pi and run

python3 screen-calendar-get.py

The script will prompt you to visit a URL in your browser and then wait. Copy the URL, open it in a browser and you will go through the login process. When the OAuth workflow tries to redirect back (and fails), copy the URL it was trying to go to (eg: http://localhost:8080/...) and in another SSH session with the Raspberry Pi,

curl "http://localhost:8080/..." 

On the first screen you should see the auth flow complete, and a new token.pickle file appears. The Python script should now be able to run in the future without prompting required.

Run it

Run ./run.sh which should query Climacell, PiHole, Google Calendar. It will then create a png, convert to a 1-bit black and white bmp, then display the bmp on screen.

Using a 1-bit, low grade BMP is what allows the screen to refresh relatively quickly. Calling the BCM code to do it takes about 6 seconds. Rendering a high quality PNG or JPG and rendering to screen with Python takes about 35 seconds.

Waveshare documentation and sample code

Waveshare have a user manual which you can get to from their Wiki

The Waveshare demo repo is here. Assuming all dependencies are installed, these demos should work.

git clone https://github.com/waveshare/e-Paper waveshare-epaper-sample
cd waveshare-epaper-sample

Run the BCM2835 demo

cd ~/waveshare-epaper-sample/7.5inch_e-paper_code/RaspberryPi/bcm2835/
make
sudo ./epd

Run the WiringPI demo

cd ~/waveshare-epaper-sample/7.5inch_e-paper_code/RaspberryPi/wiringpi/
make
sudo ./epd

Run the Python3 demo

cd ~/waveshare-epaper-sample/7.5inch_e-paper_code/RaspberryPi/python3/
sudo python3 main.py