fb-dash/README.md

FBDASH - lightweight dashboard for the RaspberryPi without X (using framebuffer only)

Get the sources

In order to setup the dashboard start with cloning this repo ;)

git clone https://git.klelifo.de/flo/fb-dash
cd fb-dash

Connect the display to the RaspberryPi

Here is some info on how to wire the display to the RaspberryPi.

Full connection diagram (9 wires needed)

Wire the display connector according to the connector scheme below.
NOTE: The 56 Ohm resistor is suggested for safety reasons - but it also seems to work fine wihtout it

ILI9341                         RaspberryPi
===============================================================
SDO/MISO ---------------------- MISO | GPIO 9  | PIN 21
LED ----------| 56 Ohm |------- PWM  | GPIO 18 | PIN 12 
SCK --------------------------- SCLK | GPIO 11 | PIN 23
SDI/MOSI ---------------------- MOSI | GPIO 10 | PIN 19
DC/RS -------------------------      | GPIO 24 | PIN 18
RESET -------------------------      | GPIO 25 | PIN 22
CS ---------------------------- CE0  | GPIO 8  | PIN 24
GND --------------------------- GND  |         | PIN 9,14,20,25
VCC --------------------------- 3,3V |         | PIN 1,17

Minimal connection diagram (7 wires needed)

Wire the display connector according to the connector scheme below.
NOTE: The 56 Ohm resistor is suggested for safety reasons - but it also seems to work fine wihtout it

ILI9341                         RaspberryPi
===============================================================
SDO/MISO ---------------------- MISO | GPIO 9  | PIN 21
LED ----------| 56 Ohm |------- VCC (soldered directly onto the display connector)
SCK --------------------------- SCLK | GPIO 11 | PIN 23
SDI/MOSI ---------------------- MOSI | GPIO 10 | PIN 19
DC/RS -------------------------      | GPIO 24 | PIN 18
RESET ------------------------- VCC (soldered directly onto the display connector)
CS ---------------------------- CE0  | GPIO 8  | PIN 24
GND --------------------------- GND  |         | PIN 9,14,20,25
VCC --------------------------- 3,3V |         | PIN 1,17

Some explanation

      |---------> Power
GND --|
VCC --|

      |---------> SPI Interface (data transfer)
MISO -| 
MOSI -|
SCK --|
CS ---|
      
      |---------> Data/Command switch
DC/RS |           (indicates whether the transfered data is a command or display data)

      |---------> Power to the backgroud lighting
LED --|

      |---------> Resets the display controller when pulled low
RESET |

Configure the display

TL;DR just run make rpi-config

Some work is needed before we can actually use the ILI9341 display with the RaspberryPi.
Essentially we need to

• Enable the SPI interface
• Load the fbtft_device kernel module with the correct parameters to get a working /dev/fb1 framebuffer device.

Enable SPI interface on the raspberry pi

echo "dtparam=spi=on" | sudo tee -a /boot/config

Activate modules to be loaded at boot

echo "spi_bcm2835" | sudo tee -a /etc/modules
echo "fbtft_device" | sudo tee -a /etc/modules
echo "options fbtft_device name=rpi-display gpios=reset:25,dc:24,led:18" | sudo tee -a /etc/modprobe.d/fbtft_device.conf

Setup fbdash binary

TL;DR just run sudo apt install -y libmariadb2 && make install

After the display is setup we can build and install the fbdash binary.

Build the sources

sudo apt install libmariadb2
make

Install in /usr/bin

sudo make install

Test it

fbdash

Use systemd for regular updates

While we could also use cron for regular execution of the fbdash binary I opted to use systemd this time.
The future is now ... ;)

Install unit files

TL;DR just run make systemd-config

The following files use systemd to setup a regular update of the dashboard screen (60s by default).
If you like to change the default, just edit the fbdash.timer file before reloading systemctl

sudo cp setup/fbdash.service setup/fbdash.timer /etc/systemd/system
sudo systemctl daemon-reload
sudo systemctl enable fbdash.timer
sudo systemctl start fbdash.timer

Check timers

systemctl list-timers
NEXT                          LEFT       LAST                          PASSED      UNIT                         ACTIVATES
Wed 2022-05-04 14:16:10 CEST  28s left   Wed 2022-05-04 14:15:10 CEST  31s ago     fbdash.timer                 fbdash.service
...

Controlling the backlight

It's a bit counterintuitive but according to Notro's wiki you can control the backlight like this (tested, works!):

Write a "1" to turn it off

echo 1 | sudo tee /sys/class/backlight/fb_ili9341/bl_power

and a "0" to turn it on

echo 0 | sudo tee /sys/class/backlight/fb_ili9341/bl_power