first re-commit.

pigpio-master/EXAMPLES/CPP/WIEGAND_CODE/wiegand.cpp

@@ -0,0 +1,116 @@
+#include <pigpio.h>
+
+#include "wiegand.hpp"
+
+Wiegand::Wiegand(int gpio_0, int gpio_1, WiegandCB_t callback, int timeout)
+{
+   /*
+      Instantiate with the gpio for 0 (green wire), the gpio for 1
+      (white wire), the callback function, and the bit timeout in
+      milliseconds which indicates the end of a code.
+
+      The callback is passed the code length in bits and the value.
+   */
+
+   mygpio_0 = gpio_0;
+   mygpio_1 = gpio_1;
+
+   mycallback = callback;
+
+   mytimeout = timeout;
+
+   in_code = 0;
+
+   gpioSetMode(gpio_0, PI_INPUT);
+   gpioSetMode(gpio_1, PI_INPUT);
+
+   gpioSetPullUpDown(gpio_0, PI_PUD_UP);
+   gpioSetPullUpDown(gpio_1, PI_PUD_UP);
+
+   gpioSetAlertFuncEx(gpio_0, _cbEx, this);
+   gpioSetAlertFuncEx(gpio_1, _cbEx, this);
+}
+
+void Wiegand::_cb(int gpio, int level, uint32_t tick)
+{
+   /*
+      Accumulate bits until both gpios 0 and 1 timeout.
+   */
+
+   if (level == 0) /* a falling edge indicates a new bit */
+   {
+      if (!in_code)
+      {
+         bits = 1;
+         num = 0;
+
+         in_code = 1;
+         code_timeout = 0;
+
+         gpioSetWatchdog(mygpio_0, mytimeout);
+         gpioSetWatchdog(mygpio_1, mytimeout);
+      }
+      else
+      {
+         bits++;
+         num <<= 1;
+      }
+
+      if (gpio == mygpio_0)
+      {
+         code_timeout &= 2; /* clear gpio 0 timeout */
+      }
+      else
+      {
+         code_timeout &= 1; /* clear gpio 1 timeout */
+         num |= 1;
+      }
+   }
+   else if (level == PI_TIMEOUT)
+   {
+      if (in_code)
+      {
+         if (gpio == mygpio_0)
+         {
+            code_timeout |= 1; /* timeout gpio 0 */
+         }
+         else
+         {
+            code_timeout |= 2; /* timeout gpio 1 */
+         }
+
+         if (code_timeout == 3) /* both gpios timed out */
+         {
+            gpioSetWatchdog(mygpio_0, 0);
+            gpioSetWatchdog(mygpio_1, 0);
+
+            in_code = 0;
+
+            (mycallback)(bits, num);
+         }
+      }
+   }
+}
+
+void Wiegand::_cbEx(int gpio, int level, uint32_t tick, void *user)
+{
+   /*
+      Need a static callback to link with C.
+   */
+
+   Wiegand *mySelf = (Wiegand *) user;
+
+   mySelf->_cb(gpio, level, tick); /* Call the instance callback. */
+}
+
+
+void Wiegand::cancel(void)
+{
+   /*
+      Cancel the Wiegand decoder.
+   */
+
+   gpioSetAlertFuncEx(mygpio_0, 0, this);
+   gpioSetAlertFuncEx(mygpio_1, 0, this);
+}
+