pigpio/EXAMPLES/CPP/WIEGAND_CODE/wiegand.cpp

117 lines
2.3 KiB
C++

#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);
}