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| 两侧同时换到之前的修订记录 前一修订版 后一修订版 | 前一修订版 | ||
|
mp_key_led [2022/02/24 14:35] gongyusu |
mp_key_led [2023/07/31 15:59] (当前版本) group003 |
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| 行 155: | 行 155: | ||
| </code> | </code> | ||
| - | 修改引脚编号，将它从连接到Pico核心板内部LED的引脚25更改为连接到学习板上红色LED的引脚19。这个LED的名称也最好随之修改，比如改为led_red。程序中所有用到该LED的地方，都要把名字修改过来: | + | 修改引脚编号，将它从连接到Pico核心板内部LED的引脚25更改为连接到学习板上红色LED的引脚26。这个LED的名称也最好随之修改，比如改为led_red。程序中所有用到该LED的地方，都要把名字修改过来: |
| <code python> | <code python> | ||
| import machine | import machine | ||
| import utime | import utime | ||
| - | led_red = machine.Pin(19, machine.Pin.OUT) | + | led_red = machine.Pin(26, machine.Pin.OUT) |
| while True: | while True: | ||
| 行 218: | 行 218: | ||
| import utime | import utime | ||
| - | key1 = machine.Pin(12, machine.Pin.IN, machine.Pin.PULL_DOWN) | + | key1 = machine.Pin(12, machine.Pin.IN, machine.Pin.PULL_UP) |
| while True: | while True: | ||
| - | if key1.value() == 1: | + | if key1.value() == 0: |
| print("You pressed the button!") | print("You pressed the button!") | ||
| utime.sleep(2) | utime.sleep(2) | ||
| 行 243: | 行 243: | ||
| <code python> | <code python> | ||
| - | led_red = machine.Pin(19, machine.Pin.OUT) | + | led_red = machine.Pin(26, machine.Pin.OUT) |
| - | key1 = machine.Pin(12, machine.Pin.IN, machine.Pin.PULL_DOWN) | + | key1 = machine.Pin(12, machine.Pin.IN, machine.Pin.PULL_UP) |
| </code> | </code> | ||
| 行 250: | 行 250: | ||
| <code python> | <code python> | ||
| while True: | while True: | ||
| - | if key1.value() == 1: | + | if key1.value() == 0: |
| </code> | </code> | ||
| 行 271: | 行 271: | ||
| import utime | import utime | ||
| led_red = machine.Pin(19, machine.Pin.OUT) | led_red = machine.Pin(19, machine.Pin.OUT) | ||
| - | key1 = machine.Pin(12, machine.Pin.IN, machine.Pin.PULL_DOWN) | + | key1 = machine.Pin(12, machine.Pin.IN, machine.Pin.PULL_UP) |
| while True: | while True: | ||
| - | if key1.value() == 1: | + | if key1.value() == 0: |
| led_red.value(1) | led_red.value(1) | ||
| utime.sleep(2) | utime.sleep(2) | ||
| 行 290: | 行 290: | ||
| + | <WRAP center round tip 60%> | ||
| + | 以下部分为其它与LED控制相关的参考案例。 | ||
| + | </WRAP> | ||
| ### 5. 案例汇总 | ### 5. 案例汇总 | ||
| 行 298: | 行 301: | ||
| # rgb-blink.py | # rgb-blink.py | ||
| - | # RED LED - Pico GPIO 19 | + | # RED LED - Pico GPIO 26 |
| - | # GREEN LED - Pico GPIO 18 | + | # GREEN LED - Pico GPIO 22 |
| - | # BLUE LED - Pico GPIO 17 | + | # BLUE LED - Pico GPIO 21 |
| - | # YELLOW LED - Pico GPIO 16 | + | # YELLOW LED - Pico GPIO 20 |
| # EETree Info & Tech 2021 | # EETree Info & Tech 2021 | ||
| # https://www.eetree.cn | # https://www.eetree.cn | ||
| 行 309: | 行 312: | ||
| import utime | import utime | ||
| - | led_red = machine.Pin(19, machine.Pin.OUT) | + | led_red = machine.Pin(26, machine.Pin.OUT) |
| - | led_green = machine.Pin(18, machine.Pin.OUT) | + | led_green = machine.Pin(22, machine.Pin.OUT) |
| - | led_blue = machine.Pin(17, machine.Pin.OUT) | + | led_blue = machine.Pin(21, machine.Pin.OUT) |
| - | led_yellow = machine.Pin(16,machine.Pin.OUT) | + | led_yellow = machine.Pin(20,machine.Pin.OUT) |
| 行 382: | 行 385: | ||
| import utime | import utime | ||
| - | key1 = machine.Pin(12, machine.Pin.IN, machine.Pin.PULL_DOWN) | + | key1 = machine.Pin(12, machine.Pin.IN, machine.Pin.PULL_UP) |
| key2 = machine.Pin(13, machine.Pin.IN, machine.Pin.PULL_UP) | key2 = machine.Pin(13, machine.Pin.IN, machine.Pin.PULL_UP) | ||
| while True: | while True: | ||
| - | if key1.value() == 1: | + | if key1.value() == 0: |
| print("key1 pressed") | print("key1 pressed") | ||
| | | ||
| 行 400: | 行 403: | ||
| # interrrupt-toggle-demo.py | # interrrupt-toggle-demo.py | ||
| - | # RED LED - Pico GPIO 19 | + | # RED LED - Pico GPIO 26 |
| - | # GREEN LED - Pico GPIO 18 | + | # GREEN LED - Pico GPIO 22 |
| # KEY1 - Pico GPIO 12 | # KEY1 - Pico GPIO 12 | ||
| 行 411: | 行 414: | ||
| import utime | import utime | ||
| - | led_red = machine.Pin(19, machine.Pin.OUT) | + | led_red = machine.Pin(26, machine.Pin.OUT) |
| - | led_green = machine.Pin(18, machine.Pin.OUT) | + | led_green = machine.Pin(22, machine.Pin.OUT) |
| led_red.value(0) | led_red.value(0) | ||
| led_green.value(0) | led_green.value(0) | ||
| - | key1 = machine.Pin(12, machine.Pin.IN, machine.Pin.PULL_DOWN) | + | key1 = machine.Pin(12, machine.Pin.IN, machine.Pin.PULL_UP) |
| def int_handler(pin): | def int_handler(pin): | ||
| 行 428: | 行 431: | ||
| key1.irq(handler=int_handler) | key1.irq(handler=int_handler) | ||
| - | button_red.irq(trigger=machine.Pin.IRQ_RISING, handler=int_handler) | + | key1.irq(trigger=machine.Pin.IRQ_FALLING , handler=int_handler) |
| while True: | while True: | ||
| 行 441: | 行 444: | ||
| # switch-led-demo.py | # switch-led-demo.py | ||
| - | # RED LED - Pico GPIO 19 | + | # RED LED - Pico GPIO 26 |
| - | # GREEN LED - Pico GPIO 18 | + | # GREEN LED - Pico GPIO 22 |
| - | # BLUE LED - Pico GPIO 17 | + | # BLUE LED - Pico GPIO 21 |
| # BLACK BUTTON - Pico GPIO 2 - Pin 4 | # BLACK BUTTON - Pico GPIO 2 - Pin 4 | ||
| 行 453: | 行 456: | ||
| import utime | import utime | ||
| - | led_red = machine.Pin(19, machine.Pin.OUT) | + | led_red = machine.Pin(26, machine.Pin.OUT) |
| - | led_green = machine.Pin(18, machine.Pin.OUT) | + | led_green = machine.Pin(22, machine.Pin.OUT) |
| - | led_blue = machine.Pin(17, machine.Pin.OUT) | + | led_blue = machine.Pin(21, machine.Pin.OUT) |
| led_red.value(0) | led_red.value(0) | ||
| 行 503: | 行 506: | ||
| </code> | </code> | ||
| - | |||
| - | 来自FPGA4FUN上的介绍 | ||
| - | 理想的LED控制是电流源，控制器的引脚是电压控制的，所以一个简单的解决方案是添加一个电阻与LED串联，电阻的阻值从100Ω到1KΩ都很常见。 | ||
| - | |||
| - | LED (Light Emitting Diode)是一种半导体器件，当电流通过它时，它就会发光。LED符号看起来像一个二极管，有一个阳极(+)和阴极(-)。 | ||
| - | 一个LED就像一个二极管，用一种方式导电，用另一种方式阻挡。 | ||
| - | |||
| - | 像所有二极管一样，它也有一个阈值电压。普通红色LED的阈值电压约为2.0V。2.0V以下不发光(无电流通过LED)。在2.0V以上，LED导电，光强度取决于通过LED的电流。 | ||
| - | |||
| - | LED有两个不能超过的物理极限: | ||
| - | 最大正向电流(即最大光强)。最大值通常是几个10的mA。 | ||
| - | 最大反向电压(即使当LED被反向偏置时没有电流通过，也不要反向偏置太多)。反向电压限制通常为5V…比普通二极管低得多! | ||