pi-rack-oled (U6143_ssd1306)

This version extends the work of darkgrue and Gosherm, it provides the following features over the original Uctronics version:

Displays hostname instead of IP address
Top row is never deleted
Correctly display CPU temperature units of measurement
Added /proc/stat CPU calculation and enabled in favor of top (should be more accurate)
Added df disk free space calculation and enabled in favor of statfs() (should be more portable)
Refactored the way numbers were being pushed to the display that should result in better formatting
- Fit decimals by width using significant figures
- Right-justify fields (against labels)
Fixed -Wall compiler warnings
More robust error handling
Added /contrib directory, support scripts
- script to tar up files
- systemd service script

I2C

Begin by enabling the I2C interface:

sudo raspi-config

Choose Interface Options | I2C, then answer Yes to whether you would like the ARM I2C interface to be enabled.

Install Git and library dependencies

sudo apt update
sudo apt install git -y

Clone project

git clone https://github.com/davidjbradshaw/pi-rack-oled.git

Compile

cd pi-rack-oled/C
make clean && make

Run

sudo ./display

Add automatic start script

Copy the binary file to /usr/local/bin/:

sudo cp ./display /usr/local/bin/

Choose one of the following configuration options (systemd or rc.local):

sudo cp ../contrib/U6143_ssd1306.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable U6143_ssd1306.service
sudo systemctl start U6143_ssd1306.service

OR add the startup command to the rc.local script (not recommended)

sudo nano /etc/rc.local

and add the command to the rc.local file:

/usr/local/bin/display &

Reboot your system:

sudo reboot now