参考

树莓派Pico‌的pio指令

diagram.json

{
  "version": 1,
  "author": "Anonymous maker",
  "editor": "wokwi",
  "parts": [
    {
      "type": "chip-scope",
      "id": "scope1",
      "top": 135.42,
      "left": 369.6,
      "attrs": {
        "sampleTimeUs": "100",
        "sampleTimeMs": "0",
        "triggerChannel": "0",
        "triggerMode": "1",
        "crtColor": "0",
        "trace0Color": "14",
        "trace1Color": "12",
        "trace2Color": "10",
        "trace3Color": "2"
      }
    },
    { "type": "wokwi-pi-pico", "id": "pico", "top": 0, "left": 0, "attrs": {} },
    {
      "type": "wokwi-led",
      "id": "led1",
      "top": -2.67,
      "left": -65.33,
      "attrs": { "color": "red" }
    },
    { "type": "wokwi-slide-switch", "id": "sw1", "top": 33.2, "left": -188.9, "attrs": {} },
    { "type": "wokwi-vcc", "id": "vcc1", "top": 115.96, "left": -163.2, "attrs": {} },
    { "type": "wokwi-gnd", "id": "gnd1", "top": 115.2, "left": -211.8, "attrs": {} }
  ],
  "connections": [
    [ "pico:GP5", "led1:A", "green", [ "h0" ] ],
    [ "pico:GND.2", "led1:C", "black", [ "h0" ] ],
    [ "scope1:D0", "pico:GP5", "green", [ "h-249.6", "v-182.4", "h-144", "v86.4" ] ],
    [ "sw1:1", "gnd1:GND", "green", [ "v9.6", "h-28.8" ] ],
    [ "sw1:3", "vcc1:VCC", "green", [ "v28.8", "h19.4", "v57.6", "h-9.6" ] ],
    [ "sw1:2", "pico:GP4", "green", [ "v19.2", "h76.9", "v-28.8" ] ]
  ],
  "dependencies": { "chip-scope": "github:Dlloydev/Wokwi-Chip-Scope@1.0.7" }
}

main.py (简单闪烁)

from machine import Pin
import rp2

# =========================
# PIO 程序：LED 闪烁
# =========================
@rp2.asm_pio(
    set_init=rp2.PIO.OUT_LOW   # LED 初始为低
)
def blink():
    wrap_target()
    set(pins, 1)   [31]        # LED ON，延时
    nop()   [31]        
    set(pins, 0)   [31]        # LED OFF，延时
    wrap()

# =========================
# StateMachine 初始化
# =========================
sm = rp2.StateMachine(
    0,
    blink,
    freq=2000,                # PIO 时钟频率
    set_base=Pin(5)          # 板载 LED（Pico）
)

sm.active(1)

main.py （多个状态机一起工作）

from rp2 import PIO, StateMachine, asm_pio
from machine import Pin
import time
 
@asm_pio(set_init=PIO.OUT_LOW)
def led_quarter_brightness():
    set(pins, 0)[2]
    set(pins, 1)
 
@asm_pio(set_init=PIO.OUT_LOW)
def led_half_brightness():
    set(pins, 0)
    set(pins, 1)
 
@asm_pio(set_init=PIO.OUT_HIGH)
def led_full_brightness():
    set(pins, 1)
 
sm1 = StateMachine(1, led_quarter_brightness, freq=2000, set_base=Pin(5))
sm2 = StateMachine(2, led_half_brightness, freq=2000, set_base=Pin(5))
sm3 = StateMachine(3, led_full_brightness, freq=2000, set_base=Pin(5))
 
print(2) 
while(True):
    sm1.active(1)
    time.sleep(1)
    sm1.active(0)
    sm2.active(1)
    time.sleep(1)
    sm2.active(0)
    sm3.active(1)
    time.sleep(1)
    sm3.active(0)

main.py (外部引脚决定如何闪烁)

from machine import Pin
import rp2

@rp2.asm_pio(set_init=rp2.PIO.OUT_LOW)
def gpio5_controller():
    label("check")
    jmp(pin, "high_mode")   # GPIO4 == 1?

    # Low mode: 1 high, 2 low
    set(pins, 1) [31]
    set(pins, 0) [31]
    set(pins, 0) [31]
    jmp("check")

    label("high_mode")
    # High mode: 2 high, 1 low
    set(pins, 1) [31]
    set(pins, 1) [31]
    set(pins, 0) [31]
    jmp("check")

# 配置引脚
Pin(4, Pin.IN, Pin.PULL_DOWN)  # 确保输入稳定
sm = rp2.StateMachine(0, gpio5_controller, freq=5000, set_base=Pin(5), jmp_pin=Pin(4))
sm.active(1)

main.py cpu->pio(传递数据)

from machine import Pin
import rp2
import time

# ==============================
# 配置（固定 1 kHz 方波）
# ==============================
HALF_PERIOD_US = 500  # 半周期 500 µs → 完整周期 1 ms
PIN_OUT = 5

# ==============================
# PIO 程序：输出 n 个周期方波，半周期从 FIFO 获取
# ==============================
@rp2.asm_pio(
    set_init=rp2.PIO.OUT_LOW,
    autopull=False,
    autopush=True  # push 完成信号到 FIFO
)
def square_wave_n_cycles():
    pull()           # 获取半周期
    mov(x, osr)
    pull()           # 获取周期数
    mov(y, osr)
    label("cycle")
    # 高电平
    set(pins, 1)
    label("high_wait")
    jmp(x_dec, "high_wait")
    mov(x, osr)     # 恢复 X
    # 低电平
    set(pins, 0)
    label("low_wait")
    jmp(x_dec, "low_wait")
    mov(x, osr)     # 恢复 X
    # 周期计数
    jmp(y_dec, "cycle")
    # 完成信号
    push()           # 推送一个值到 CPU FIFO

# ==============================
# 初始化 StateMachine
# ==============================
sm = rp2.StateMachine(
    0,
    square_wave_n_cycles,
    freq=1_000_000,  # 1 MHz → 每条指令 1 µs
    set_base=Pin(PIN_OUT)
)
sm.active(1)

# ==============================
# 核心函数：CPU 发送半周期 + 周期数，等待完成
# ==============================
def send_and_wait(half_period_us, cycles):
    if cycles <= 0 or half_period_us <= 0:
        return
    sm.put(half_period_us - 1)  # 半周期
    sm.put(cycles)              # 周期数
    # 等待 PIO 推送完成信号
    while sm.rx_fifo() == 0:
        pass
    sm.get()                    # 清空完成信号
while True:
    print(f"输出固定 1 kHz 方波（半周期={HALF_PERIOD_US} µs）")
    print("-" * 40)
    cycles = 3
    print(f"CPU 发: {cycles} 个周期")
    send_and_wait(HALF_PERIOD_US, cycles)
    print(f"PIO 执行完成 ({cycles} cycles)\n")
    time.sleep_ms(200)
    cycles = 5
    print(f"CPU 发: {cycles} 个周期")
    send_and_wait(HALF_PERIOD_US, cycles)
    print(f"PIO 执行完成 ({cycles} cycles)\n")
    print("全部完成！GPIO5 已输出对应方波周期")

main.py pio->cpu(传递数据)

from machine import Pin
import rp2
import time

PIN_IN = 4

@rp2.asm_pio()
def edge_detector():
    in_(pins, 1)
    mov(x, isr)
    label("loop")
    in_(pins, 1)
    mov(y, isr)
    jmp(x_not_y, "change")
    jmp("loop")
    label("change")
    mov(isr, y)
    push()
    mov(x, y)
    jmp("loop")

sm_in = rp2.StateMachine(0, edge_detector, freq=2000, in_base=Pin(PIN_IN))
sm_in.active(1)

print("检测 GPIO4 边沿...")
try:
    while True:
        if sm_in.rx_fifo():
            level = sm_in.get() & 1
            print(f"边沿！当前电平: {level}")
        time.sleep_us(100)
except KeyboardInterrupt:
    sm_in.active(0)
    print("结束")