segunda-feira, março 16, 2020

Raspberry Pi LCD Display: 16×2 Characters Display (HD44780)

The most common controller of multi-line character displays is the HD44780. There are several Raspberry Pi LCD display sizes (8×2, 16×2, 20×4, etc.) that run with it. In this tutorial, I will show how to use a 16×2 character display and also run a test script.
A few words said in advance: In this tutorial, all pins are addressed directly, which occupies quite a few GPIOs. Another method is the connection via I2C.

Required Hardware Parts

The following parts are required:


In this case, I refer to the pin numbering (GPIO.BOARD), not to the GPIO numbers:

LCD Pinto RPi GPIODescription
 1. VSS Pin 6 (GND)Supply Voltage (ground)
 2. VDD Pin 2 (5V)Supply Voltage 5V
 3. V0 Pin 6 (GND)Contrast Voltage
 4. RS Pin 7 (GPIO4)Register Selection (0: Command Register, 1: Data Register)
 5. RW Pin 6 (GND) Read/Write (0: Write Modus, 1: Read Modus)
 6. E Pin 11 (GPIO17)Clock Edge
 7. D0 –Data Line 0
 8. D1 –Data Line 1
 9. D2 –Data Line 2
 10. D3 –Data Line 3
 11. D4 Pin 12 (GPIO18)Data Line 4
 12. D5 Pin 15 (GPIO22)Data Line 5
 13. D6 Pin 16 (GPIO23)Data Line 6
 14. D7 Pin 18 (GPIO24)Data Line 7
 15. A Pin 2 (5V) (mit Poti)Backlight Anode
 16. K Pin 6 (GND)Backlight Cathode

The backlight can be adjusted by turning the potentiometer. Some displays cannot stand 5V for the backlight, so you should either look at the datasheet or at least always connect a 470Ω – 510Ω resistor.

Testing the Raspberry Pi LCD Display

You can either view the script I used here or just download it and try.
chmod +x
If you have chosen a different display or pin assignment, do not forget to adapt the script.
Through the simple control, you can create different scripts, which, for example, show the status of the Pi.

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