init repo

wiegand.py

@@ -0,0 +1,70 @@
+from machine import Pin, Timer
+
+class Wiegand:
+    def __init__(self, pin0, pin1, callback, buf_len=34):
+        self.pin0 = Pin(pin0, Pin.IN, Pin.PULL_UP)
+        self.pin1 = Pin(pin1, Pin.IN, Pin.PULL_UP)
+        self.callback = callback
+        self.buf = bytearray(buf_len)
+        self.idx = 0
+        self.timer = Timer(-1)
+
+        self.pin0.irq(trigger=Pin.IRQ_FALLING, handler=self._irq)
+        self.pin1.irq(trigger=Pin.IRQ_FALLING, handler=self._irq)
+
+    def _irq(self, p):
+        # 同时读取两根线，组合成 0b01 (bit=0) 或 0b10 (bit=1)
+        state = (self.pin1.value() << 1) | self.pin0.value()
+        if state not in (0b01, 0b10):
+            return
+
+        if self.idx < len(self.buf):
+            self.buf[self.idx] = state
+            self.idx += 1
+            if self.idx == 1:
+                # 只启动一次，80ms 后触发解析
+                self.timer.init(period=80, mode=Timer.ONE_SHOT, callback=self._timeout)
+
+    def _timeout(self, t):
+        n = self.idx
+        self.idx = 0
+        data = bytes(self.buf[:n])       # 拷贝，防止中断覆盖
+        self._parse(n, data)
+
+    def _parse(self, n, data):
+        if n == 26 and self._check_parity(data, 26):
+            # 剔除首尾校验位，保留中间 24 位有效载荷
+            payload = self._extract_bits(data, 1, 24)
+            self.callback('wg26', payload)
+        elif n == 34 and self._check_parity(data, 34):
+            # 剔除首尾校验位，保留中间 32 位有效载荷
+            payload = self._extract_bits(data, 1, 32)
+            self.callback('wg34', payload)
+        elif n == 8:
+            # 键盘：低4位键值，高4位为低4位取反
+            val = self._extract_bits(data, 0, 8)
+            if ((val >> 4) ^ (val & 0x0F)) == 0x0F:
+                self.callback('keypad', val & 0x0F)
+        # 其余长度或校验失败直接丢弃
+
+    def _check_parity(self, data, bits):
+        """标准 Wiegand 奇偶校验：前一半偶数个1，后一半奇数个1"""
+        half = bits // 2
+        cnt_even = 0
+        cnt_odd = 0
+        for i in range(bits):
+            if data[i] == 0b10:          # 该比特为 1
+                if i < half:
+                    cnt_even += 1
+                else:
+                    cnt_odd += 1
+        return (cnt_even % 2 == 0) and (cnt_odd % 2 == 1)
+
+    def _extract_bits(self, data, start, count):
+        """从 data 中提取连续比特，MSB first，返回整数"""
+        val = 0
+        for i in range(start, start + count):
+            val <<= 1
+            if data[i] == 0b10:
+                val |= 1
+        return val