树莓派 Pico + LCD1602 显示个性化字符

让 LCD 显示屏显示个性化的字符，有点类似于创作一套 emoji 那样有趣。下面我们介绍实现的方法。

用到的东西

– 树莓派 Pico
– LCD1602 显示屏（带 I2C 模块）
– 面包板
– 跳线若干

接线

如图所示接线。

SCL-Pin 2 (GP1)
SDA-Pin 1(GPO)
VCC-Pin 40(VBUS)
GND-Pin 38 (GND)

编程

接线完成下面开始编程。

首先确保你的 Pico 已经安装了 MicroPython 固件。

1、下载 Thonny 编程工具。
2、打开 Thonny 在 Tools> Options> Interpreter 选择 Raspberry Pi Pico 为解释器。

下载 LCD1602 的驱动和库。
https://github.com/T-622/RPI-PICO-I2C-LCD

运行代码之前，需要确认 LCD 1602 的 I2C 地址。下载下面的代码确认 I2C 地址：
https://github.com/gigafide/pico_LCD_16x2

保存为文件之后运行，电脑上会显示一个十进制的数字。需要再通过十进制转十六进制的工具将数字转换成 I2C 地址。

实现个性化字符

使用下面的代码可以显示字符。

import machine
from machine import I2C
from lcd_api import LcdApi
from pico_i2c_lcd import I2cLcd
I2C_ADDR = 0x27
I2C_NUM_ROWS = 4
I2C_NUM_COLS = 20
i2c = I2C(0, sda=machine.Pin(0), scl=machine.Pin(1), freq=400000)
lcd = I2cLcd(i2c, I2C_ADDR, I2C_NUM_ROWS, I2C_NUM_COLS)
lcd.clear(_)
lcd.move_to(0,5)
lcd.putstr("Hello")
lcd.move_to(0,5)
lcd.putstr("World!")

你只需要修改最后四行，就可以让它显示个性化字符。个性化字符的代码可以通过这个工具创建。然后用 Python 的方法定义即可。

# smiley faces
happy = bytearray([0x00,0x0A,0x00,0x04,0x00,0x11,0x0E,0x00])
sad = bytearray([0x00,0x0A,0x00,0x04,0x00,0x0E,0x11,0x00])
grin = bytearray([0x00,0x00,0x0A,0x00,0x1F,0x11,0x0E,0x00])
shock = bytearray([0x0A,0x00,0x04,0x00,0x0E,0x11,0x11,0x0E])
meh = bytearray([0x00,0x0A,0x00,0x04,0x00,0x1F,0x00,0x00])
angry = bytearray([0x11,0x0A,0x11,0x04,0x00,0x0E,0x11,0x00])
tongue = bytearray([0x00,0x0A,0x00,0x04,0x00,0x1F,0x05,0x02])

# icons
bell = bytearray([0x04,0x0e,0x0e,0x0e,0x1f,0x00,0x04,0x00])
note = bytearray([0x02,0x03,0x02,0x0e,0x1e,0x0c,0x00,0x00])
clock = bytearray([0x00,0x0e,0x15,0x17,0x11,0x0e,0x00,0x00])
heart = bytearray([0x00,0x0a,0x1f,0x1f,0x0e,0x04,0x00,0x00])
duck = bytearray([0x00,0x0c,0x1d,0x0f,0x0f,0x06,0x00,0x00])
check = bytearray([0x00,0x01,0x03,0x16,0x1c,0x08,0x00,0x00])
cross = bytearray([0x00,0x1b,0x0e,0x04,0x0e,0x1b,0x00,0x00])
retarrow = bytearray([0x01,0x01,0x05,0x09,0x1f,0x08,0x04,0x00])

# battery icons
battery0 = bytearray([0x0E,0x1B,0x11,0x11,0x11,0x11,0x11,0x1F]))  # 0% Empty
battery1 = bytearray([0x0E,0x1B,0x11,0x11,0x11,0x11,0x1F,0x1F]))  # 16%
battery2 = bytearray([0x0E,0x1B,0x11,0x11,0x11,0x1F,0x1F,0x1F]))  # 33%
battery3 = bytearray([0x0E,0x1B,0x11,0x11,0x1F,0x1F,0x1F,0x1F]))  # 50%
battery4 = bytearray([0x0E,0x1B,0x11,0x1F,0x1F,0x1F,0x1F,0x1F]))  # 66%
battery5 = bytearray([0x0E,0x1B,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F]))  # 83%
battery6 = bytearray([0x0E,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F]))  # 100% Full
battery7 = bytearray([0x0E,0x1F,0x1B,0x1B,0x1B,0x1F,0x1B,0x1F]))  # ! Error

lcd.custom_char(0, happy);
lcd.putchar(chr(0))
#lcd.putchar(b'\x00')

https://maxpromer.github.io/LCD-Character-Creator/

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