raspi_lcd

I2C LCD Device Driver for Raspberry Pi. It supports LCD controller IC ST7032i in AQM0802A, AQM1602A, AQM1602Y, and GROVE-LCD, and HD44780 and it’s compatible IC with PCF8574T or PCF8574A in General 1602 LCDs.

Supported Raspberry Pi: 1, 2, 3, 4, Zero, Zero W, Zero W2.

And only one code “example_Pi5.sh” is for Rapberry Pi 5.

Features

I2C interface signals SCL and SDA can be directly connected to Raspberry Pi.
(It does not require an I2C repeater and pull-up resistors.)
Supports to display some Latin characters for French, and all of Japanese Katakana.
Python code examples are available. NEW!

Language

Select language to transrate this page:

Schematics

Schematic1

On the above Schematics, the power supply for the LCD is from GPIO16, to control the power and hardware reset function from Raspberry Pi.

Schematic2

This is for CPU Load Monitor example_cpu.sh on GitHub.

Schematic3

Handmade Examples

The picture below shows Xiamen Zettler Electronics AQM1602 LCD connected to the Raspberry Pi Zero. Other Raspberry Pis (1/2/3/4 etc.) can be connected in the same way.

AQM1602

Also supports General 1602 LCDs (HD44780 + PCF8574T / PCF8574A):

General1602

It works on the 1st generation Raspbeery Pi:

RaspPi1

It can display French Latin letters, if your LCD hardware supports (Grove LCD cannot).

Latin

The following pictures show an example of CPU Load Monitor which displays a time, load and temperature of CPU, temperature, and percentage of used SD card and used memory. Enter the command “./example_cpu.sh” to execute this source code example_cpu.sh.

CPU_Load

I made it to display the radio channel name of the Internet radio, the artist and the song names of the jukebox. You can use it in another repository bokunimowakaru/audio/radio/pi.

Radio

Music

Install “raspi_lcd” to your Raspberry Pi

$ cd ⏎
$ sudo apt install raspi-gpio ⏎ (for legacy OS)
$ sudo apt install git ⏎ (for LITE Version OS)
$ git clone https://bokunimo.net/git/raspi_lcd ⏎
$ cd ~/raspi_lcd ⏎
$ make clean ⏎
$ make ⏎

Testing

The first, run example.py for testing the driver works:

$ cd ~/raspi_lcd ⏎
$ ./example.py ⏎

After that, use “raspi_lcd” command which can be set full optional functions:

$ cd ~/raspi_lcd ⏎
$ ./raspi_lcd -a3E -i -w16 "Raspberry Pi LCD by bokunimo.net" ⏎
(The arg "-a3e" sets I2C address to 3E, arg "-w16" sets the display digit width.)

Usage

“-h” option shows usage:

$ ./raspi_lcd -h
Usage: ./raspi_lcd (Version 1.04)
  ./raspi_lcd [-i] [-a address] [-f] [-r port] [-w lcd_width] [-y row] text...
  ./raspi_lcd [-i] [-a address] [-f] [-r port] [-w lcd_width] [-y row] [-b|-d] value...
  echo text... | ./raspi_lcd [-i] [-f] [-r port] [-w lcd_width] [-y row]
  ./raspi_lcd -h # shows this help
  ./raspi_lcd -q # releases I2C ports

    options:
      -i      ignore I2C communication errors
      -aADR   set i2c address in hex (defalut=3E)
      -s      slowdown I2C communication mode
      -rPORT  set GPIO port number of reset LCD pin; number for PORT
      -wWIDTH set display digits; 8 or 16 for WITDH
      -yROW   set display row; 1 or 2 for ROW
      -b      display bar graph
      -d      display dot graph
      text... display text string on the LCD
      -n      skip initializing LCD
      -f      use standard input, continuously
      -qPORT  restore GPIO port and I2C ports
      -h      display this help on the terminal
      -v      show version (for 1.01 and greater)

Example Code (Python Script)

See example.py on GitHub.

pi@raspberrypi:~/raspi_lcd $ ./example.py
2023/01/13 23:22:34 LCD initialized
2023/01/13 23:22:34 Example for AQM1602A/Y/Grove ----------
2023/01/13 23:22:35 LCD 2023/01/13 23:22 / AQM1602A/Y/Grove
2023/01/13 23:22:41 LCD 0123456789ABCDEF
2023/01/13 23:22:41 LCD 16 ｹﾀ ﾏﾃﾞ ﾋｮｳｼﾞ!
2023/01/13 23:22:46 LCD Done
2023/01/13 23:22:46 LCD initialized
2023/01/13 23:22:46 Example for AQM0802A ------------------
2023/01/13 23:22:47 LCD 23:22:46 / AQM0802A
2023/01/13 23:22:53 LCD 01234567
2023/01/13 23:22:53 LCD 8ｹﾀﾋｮｳｼﾞ
2023/01/13 23:22:58 LCD restore GPIO16 to free
2023/01/13 23:23:03 LCD Done

Example Code (Bash Script)

See example.sh on GitHub.

pi@raspberrypi:~/raspi_lcd $ ./example.sh
2023/01/05 12:27:40 STARTED -------------------------------
2023/01/05 12:27:40 LCD reset GPIO16
2023/01/05 12:27:43 LCD I2C LCD Driver / by ﾎﾞｸﾆﾓﾜｶﾙRasPi
2023/01/05 12:27:48 Example for AQM1602A/Y/Grove ----------
2023/01/05 12:27:51 LCD 2023/01/05 12:27:48 / AQM1602A/Y/Grove
2023/01/05 12:27:59 LCD 0123456789ABCDEF / 16 ｹﾀ ﾏﾃﾞ ﾋｮｳｼﾞ
2023/01/05 12:28:04 Example for AQM0802A ------------------
2023/01/05 12:28:07 LCD 2023/01/05 12:28:04 / AQM1602A/Y/Grove
2023/01/05 12:28:15 LCD 01234567 / 8ｹﾀﾋｮｳｼﾞ

Example Code for Grove-LCD RGB Backlight

Grove-LCD RGB Backlight needs Backlight Controller “raspi_backlight” in “/raspi_lcd/grove_rgb/”.
Please additionally install “raspi_backlight”:

$ cd ~/raspi_lcd/grove_rgb ⏎
$ make clean ⏎
$ make ⏎

The example code for Grove-LCD is in here: raspi_lcd/grove_rgb/example.sh:

pi@raspberrypi:~/raspi_lcd/grove_rgb $ ./example.sh ⏎
2023/01/05 13:58:03 STARTED -------------------------------
2023/01/05 13:58:03 RGB Backlight reset
2023/01/05 13:58:03 usage: /home/pi/raspi_lcd/grove_rgb/raspi_backlight [red] [green] [blue]
red=32(0x20), green=64(0x40), blue=16(0x10)
2023/01/05 13:58:07 LCD I2C LCD Driver / by ﾎﾞｸﾆﾓﾜｶﾙRasPi
2023/01/05 13:58:12 Example for Grove-LCD RGB Backlight ---
2023/01/05 13:58:12 RGB Backlight reset
2023/01/05 13:58:12 red=16(0x10), green=32(0x20), blue=16(0x10)
2023/01/05 13:58:15 LCD 2023/01/05 13:58:12 / Grove-LCD BLight
2023/01/05 13:58:20 RGB Backlight reset
2023/01/05 13:58:20 red=48(0x30), green=32(0x20), blue=16(0x10)
2023/01/05 13:58:23 LCD 0123456789ABCDEF / 16 ｹﾀ ﾏﾃﾞ ﾋｮｳｼﾞ
2023/01/05 13:58:28 RGB Backlight reset
2023/01/05 13:58:28 red=32(0x20), green=32(0x20), blue=16(0x10)
2023/01/05 13:58:32 LCD 2023/01/05 13:58:29 / RGB=(32,32,32)
2023/01/05 13:58:37 RGB Backlight reset
2023/01/05 13:58:37 red=16(0x10), green=48(0x30), blue=16(0x10)
2023/01/05 13:58:40 LCD 2023/01/05 13:58:37 / RGB=(16,48,32)

Grove-LCD RGB Backlight