数码管

原理简介

数码管（七段数码管）用 7 个笔画拼出数字，是显示数字最直观的器件。

工作原理：点亮不同组合的笔画，拼出 0-9 和部分字母
驱动芯片：TM1637，四位数码管模块上自带
接口：两根普通 GPIO（CLK、DIO），不是 I2C
最大好处：只用 2 个引脚就能驱动 4 位数字。如果不用 TM1637 直接驱动，四位就要占掉 12 个引脚

TM1637 用的是自己的一套两线协议，和 I2C 长得很像但不是 I2C，所以不能接到 I2C 的 SDA/SCL 上，任意两个空闲 GPIO 都可以。

典型应用

数字时钟
计数器、计分板
倒计时器
温度显示
电子秤读数

接线图

[接线图占位，后续添加]

文字说明（具体接法见下方代码注释）：

数码管 VCC → Pico 3V3
数码管 GND → Pico GND
数码管 CLK → Pico GP16
数码管 DIO → Pico GP17

示例代码

基础示例：显示数字、字母、十六进制

# ============ 接线 ============
# 数码管 VCC → Pico 3V3
# 数码管 GND → Pico GND
# 数码管 CLK → Pico GP16
# 数码管 DIO → Pico GP17
# CLK / DIO 换成任意两个空闲 GPIO 都可以，改下面 Pin() 里的脚号即可
# =============================
from machine import Pin
import tm1637
import time

# 创建对象：clk、dio 要传 Pin 对象，brightness 亮度 0-7
tm = tm1637.TM1637(clk=Pin(16), dio=Pin(17))

tm.number(1234)        # 显示整数（范围 -999 ~ 9999，右对齐）
time.sleep(2)

tm.numbers(12, 34)     # 显示 12:34，中间自带冒号
time.sleep(2)

tm.hex(0xbeef)         # 显示十六进制 BEEF
time.sleep(2)

tm.show('abcd')        # 显示字符串（最多 4 个字符）
time.sleep(2)

tm.brightness(0)       # 调到最暗
time.sleep(1)
tm.brightness(7)       # 调到最亮

进阶示例：计时器（显示分:秒）

# ============ 接线 ============
# 数码管 VCC → Pico 3V3
# 数码管 GND → Pico GND
# 数码管 CLK → Pico GP16
# 数码管 DIO → Pico GP17
# =============================
from machine import Pin
import tm1637
import time

tm = tm1637.TM1637(clk=Pin(16), dio=Pin(17))
tm.brightness(4)                      # 亮度 0-7，中间档比较舒服

start = time.ticks_ms()               # 记录起点（毫秒）

while True:
    elapsed = time.ticks_diff(time.ticks_ms(), start)   # 已经过去多少毫秒
    total_sec = elapsed // 1000                          # 换成秒
    minutes = total_sec // 60
    seconds = total_sec % 60
    tm.numbers(minutes, seconds)      # 显示 分:秒，自带冒号
    time.sleep_ms(100)                # 每 100ms 刷新一次

numbers() 的两位数字上限是 99，所以这个计时器最多显示到 99:59。

应用示例：按键计数器

# ============ 接线 ============
# 数码管 VCC → Pico 3V3
# 数码管 GND → Pico GND
# 数码管 CLK → Pico GP16
# 数码管 DIO → Pico GP17
# 按键：一脚 → GP14，另一脚 → GND（用内部上拉，不用外接电阻）
# =============================
from machine import Pin
import tm1637
import time

tm = tm1637.TM1637(clk=Pin(16), dio=Pin(17))
key = Pin(14, Pin.IN, Pin.PULL_UP)    # 按键：按下接地，读到 0

count = 0
tm.number(count)                      # 先显示 0

while True:
    if key.value() == 0:              # 按键被按下
        count += 1
        tm.number(count)              # 更新显示
        time.sleep_ms(200)            # 简单防抖，防止一次按下加好几下

注意事项

供电：TM1637 模块支持 3.3V–5V，接 Pico 的 3V3 就行。信号脚不要接 5V
不是 I2C：CLK / DIO 是普通 GPIO，虽然名字像 I2C 的 SCL / SDA，但协议不同，别接错
亮度：brightness(0-7)，0 最暗、7 最亮。数码管很费电，做电池设备时记得调低
字符支持：show() 支持 0-9、A-Z、a-z、空格、短横线 -、星号 *。传其它字符会报错
小数点：基础类 TM1637 不支持小数点，需要小数点要用 TM1637Decimal（对应带小数点的模块）
字母会变形：七段数码管只有 7 个笔画，M、W、X、K 这类字母无法准确显示，是硬件限制
刷新频率：更新太快会闪，一般留 50–100ms 间隔就够
接线长度：CLK / DIO 线别拉太长，长了容易受干扰导致显示乱码

常见问题

Q: 数码管全亮、或者显示乱码怎么办？ A: 先检查 CLK / DIO 有没有接反，再确认 VCC、GND 接好。接线松动是最常见原因。

Q: 显示的数字缺笔画怎么办？ A: 多半是供电不足或亮度太低。确认 VCC 接的是 3V3（不是悬空），再试试 tm.brightness(7)。

Q: 想显示小数点（比如 12.34）怎么办？ A: 基础类不支持，改用 TM1637Decimal 类（接线同基础示例：CLK→GP16，DIO→GP17）：

# 接线同基础示例：数码管 VCC→3V3，GND→GND，CLK→GP16，DIO→GP17
from machine import Pin
import tm1637
tm = tm1637.TM1637Decimal(clk=Pin(16), dio=Pin(17))
tm.show('12.34')      # 小数点会点亮

Q: 显示字母不全对，比如 M 显示成怪样子？ A: 正常现象。七段数码管的笔画不够，M、W、X 这类字母无法准确表示。

Q: 接了 I2C 的引脚（比如 GP8/GP9）可以吗？ A: 引脚本身可以用，但不能和 I2C 设备共用同一条线。如果同一个项目里还有 OLED，给数码管另找两个空闲 GPIO。

库文件

本页示例用到 tm1637 库，MicroPython 固件不自带，必须先把这个库文件保存到 Pico 上，否则 import tm1637 时会直接报错。

操作步骤（Thonny）

用 Thonny 连上 Pico
点菜单「文件 → 新建」，把下面的代码整段粘贴进去
点「文件 → 另存为」，在弹出的窗口里选 Raspberry Pi Pico
文件名填 tm1637.py，保存
存好后，本页示例就能正常运行了

这个库来自开源项目 mcauser/micropython-tm1637（MIT 协议），已保留原始版权声明。库里的 TM1637 类用于普通数码管，TM1637Decimal 类用于带小数点的数码管。

"""
MicroPython TM1637 quad 7-segment LED display driver
https://github.com/mcauser/micropython-tm1637

MIT License
Copyright (c) 2016-2023 Mike Causer

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
"""

__version__ = '1.3.0'

from micropython import const
from machine import Pin
from time import sleep_us, sleep_ms

TM1637_CMD1 = const(64)  # 0x40 data command
TM1637_CMD2 = const(192) # 0xC0 address command
TM1637_CMD3 = const(128) # 0x80 display control command
TM1637_DSP_ON = const(8) # 0x08 display on
TM1637_DELAY = const(10) # 10us delay between clk/dio pulses
TM1637_MSB = const(128)  # msb is the decimal point or the colon depending on your display

# 0-9, a-z, blank, dash, star
_SEGMENTS = bytearray(b'\x3F\x06\x5B\x4F\x66\x6D\x7D\x07\x7F\x6F\x77\x7C\x39\x5E\x79\x71\x3D\x76\x06\x1E\x76\x38\x55\x54\x3F\x73\x67\x50\x6D\x78\x3E\x1C\x2A\x76\x6E\x5B\x00\x40\x63')

class TM1637(object):
    """Library for quad 7-segment LED modules based on the TM1637 LED driver."""
    def __init__(self, clk, dio, brightness=7):
        self.clk = clk
        self.dio = dio

        if not 0 <= brightness <= 7:
            raise ValueError("Brightness out of range")
        self._brightness = brightness

        self.clk.init(Pin.OUT, value=0)
        self.dio.init(Pin.OUT, value=0)
        sleep_us(TM1637_DELAY)

        self._write_data_cmd()
        self._write_dsp_ctrl()

    def _start(self):
        self.dio(0)
        sleep_us(TM1637_DELAY)
        self.clk(0)
        sleep_us(TM1637_DELAY)

    def _stop(self):
        self.dio(0)
        sleep_us(TM1637_DELAY)
        self.clk(1)
        sleep_us(TM1637_DELAY)
        self.dio(1)

    def _write_data_cmd(self):
        # automatic address increment, normal mode
        self._start()
        self._write_byte(TM1637_CMD1)
        self._stop()

    def _write_dsp_ctrl(self):
        # display on, set brightness
        self._start()
        self._write_byte(TM1637_CMD3 | TM1637_DSP_ON | self._brightness)
        self._stop()

    def _write_byte(self, b):
        for i in range(8):
            self.dio((b >> i) & 1)
            sleep_us(TM1637_DELAY)
            self.clk(1)
            sleep_us(TM1637_DELAY)
            self.clk(0)
            sleep_us(TM1637_DELAY)
        self.clk(0)
        sleep_us(TM1637_DELAY)
        self.clk(1)
        sleep_us(TM1637_DELAY)
        self.clk(0)
        sleep_us(TM1637_DELAY)

    def brightness(self, val=None):
        """Set the display brightness 0-7."""
        # brightness 0 = 1/16th pulse width
        # brightness 7 = 14/16th pulse width
        if val is None:
            return self._brightness
        if not 0 <= val <= 7:
            raise ValueError("Brightness out of range")

        self._brightness = val
        self._write_data_cmd()
        self._write_dsp_ctrl()

    def write(self, segments, pos=0):
        """Display up to 6 segments moving right from a given position.
        The MSB in the 2nd segment controls the colon between the 2nd
        and 3rd segments."""
        if not 0 <= pos <= 5:
            raise ValueError("Position out of range")
        self._write_data_cmd()
        self._start()

        self._write_byte(TM1637_CMD2 | pos)
        for seg in segments:
            self._write_byte(seg)
        self._stop()
        self._write_dsp_ctrl()

    def encode_digit(self, digit):
        """Convert a character 0-9, a-f to a segment."""
        return _SEGMENTS[digit & 0x0f]

    def encode_string(self, string):
        """Convert an up to 4 character length string containing 0-9, a-z,
        space, dash, star to an array of segments, matching the length of the
        source string."""
        segments = bytearray(len(string))
        for i in range(len(string)):
            segments[i] = self.encode_char(string[i])
        return segments

    def encode_char(self, char):
        """Convert a character 0-9, a-z, space, dash or star to a segment."""
        o = ord(char)
        if o == 32:
            return _SEGMENTS[36] # space
        if o == 42:
            return _SEGMENTS[38] # star/degrees
        if o == 45:
            return _SEGMENTS[37] # dash
        if o >= 65 and o <= 90:
            return _SEGMENTS[o-55] # uppercase A-Z
        if o >= 97 and o <= 122:
            return _SEGMENTS[o-87] # lowercase a-z
        if o >= 48 and o <= 57:
            return _SEGMENTS[o-48] # 0-9
        raise ValueError("Character out of range: {:d} '{:s}'".format(o, chr(o)))

    def hex(self, val):
        """Display a hex value 0x0000 through 0xffff, right aligned."""
        string = '{:04x}'.format(val & 0xffff)
        self.write(self.encode_string(string))

    def number(self, num):
        """Display a numeric value -999 through 9999, right aligned."""
        # limit to range -999 to 9999
        num = max(-999, min(num, 9999))
        string = '{0: >4d}'.format(num)
        self.write(self.encode_string(string))

    def numbers(self, num1, num2, colon=True):
        """Display two numeric values -9 through 99, with leading zeros
        and separated by a colon."""
        num1 = max(-9, min(num1, 99))
        num2 = max(-9, min(num2, 99))
        segments = self.encode_string('{0:0>2d}{1:0>2d}'.format(num1, num2))
        if colon:
            segments[1] |= 0x80 # colon on
        self.write(segments)

    def temperature(self, num):
        if num < -9:
            self.show('lo') # low
        elif num > 99:
            self.show('hi') # high
        else:
            string = '{0: >2d}'.format(num)
            self.write(self.encode_string(string))
        self.write([_SEGMENTS[38], _SEGMENTS[12]], 2) # degrees C

    def show(self, string, colon=False):
        segments = self.encode_string(string)
        if len(segments) > 1 and colon:
            segments[1] |= 128
        self.write(segments[:4])

    def scroll(self, string, delay=250):
        segments = string if isinstance(string, list) else self.encode_string(string)
        data = [0] * 8
        data[4:0] = list(segments)
        for i in range(len(segments) + 5):
            self.write(data[0+i:4+i])
            sleep_ms(delay)

class TM1637Decimal(TM1637):
    """Library for quad 7-segment LED modules based on the TM1637 LED driver.

    This class is meant to be used with decimal display modules (modules
    that have a decimal point after each 7-segment LED).
    """

    def encode_string(self, string):
        """Convert a string to LED segments.

        Convert an up to 4 character length string containing 0-9, a-z,
        space, dash, star and '.' to an array of segments, matching the length of
        the source string."""
        segments = bytearray(len(string.replace('.','')))
        j = 0
        for i in range(len(string)):
            if string[i] == '.' and j > 0:
                segments[j-1] |= TM1637_MSB
                continue
            segments[j] = self.encode_char(string[i])
            j += 1
        return segments

数码管