ospiLCD

This is OpenSprinkler pi I2C LCD python script which gets data from OpenSprinkler API and sends to I2C LCD.

features:

• 16x2 and 20x4 I2C LCDs are supported (PCF8574T based, after some changes MCP23008 is supported too)
• first two lines are identical to LCD on OpenSprinkler 2.x (with icons)
• third and fourth lines are displaying information based on ospi status (remaining watering time, water level in %, E1 stations status)
• LCD backlight is controlled from OpenSprinkler GUI (Brightness = 0 ->> OFF, Brightness > 1 ->> ON)
• LCD is refreshed in one minute interval (can be changed in cron)
• this script in combination with Raspberry pi and I2C LCD can be used as remote OpenSprinkler LCD

Installation instructions

Install RPLCD library directly from PyPI using pip:

$ sudo pip install RPLCD

Intall smbus and i2c tools:

$ sudo apt-get install python-smbus i2c-tools

Intall ospiLCD script:

$ cd /home/pi/
$ wget  https://raw.githubusercontent.com/stanoba/ospiLCD/master/ospiLCD.py
$ chmod +x ospiLCD.py

Solder 2x3 pin header to ospi board:

Remove two 4K7 pull-up resistors from I2C LCD backpack:

Resistors are feeding 5V to Raspberry pi GPIO pins = not safe.

Connect I2C LCD to ospi pin header:

Run I2C scanner to detect all available address:

$ sudo i2cdetect -y 1

You should see I2C LCD at address 0x27:

Edit parameters (osAddress, osPort, md5hash, LCDcols, LCDrows) according your ospi and LCD in /home/pi/ospiLCD.py:

$ nano /home/pi/ospiLCD.py

Test the script if is working:

$ /home/pi/ospiLCD.py

If the script is working without error, schedule it via cron:

$ crontab -e

Add folowing line into cron:

*/1 * * * * python /home/pi/ospiLCD.py

Note: Script is executed every minute.

HW - I2C LCD adapter

You can find LCD adapter PCB in HW folder.

PCB can be ordered from PCBs.io. ($0.89 / 4pcs)

3D Printed case

STL files:https://www.thingiverse.com/thing:2576148

Output examples:

Blue LCD 16x2:

Green LCD 20x4:

Green LCD 20x4 and ospi with expansion board (E1):