static int gpio_wait(int pin)
{
char path[BUFFER_MAX];
int fd;
snprintf(path, BUFFER_MAX, "/sys/class/gpio/gpio%d/value", pin);
fd = open(path, O_RDONLY);
if (-1 == fd) {
fprintf(stderr, "Failed to open gpio for reading!\n");
return -1;
}
read(fd, path, 3);
struct pollfd p = {
.fd = fd,
.events = POLLPRI|POLLERR,
};
int r = poll(&p, 1, -1);
if(r != 1) {
fprintf(stderr, "poll() failed!\n");
close(fd);
return -1;
}
close(fd);
return 0;
}
int main(int argv, char** argc)
{
if(gpio_export(PIN)) {
return 1;
}
gpio_direction(PIN, IN);
setup();
setup_gpio(POUT, OUTPUT, PUD_OFF);
while(1) {
gpio_edge(PIN, RISING);
gpio_wait(PIN);
output_gpio(POUT, HIGH);
gpio_edge(PIN, FALLING);
gpio_wait(PIN);
output_gpio(POUT, LOW);
}
if(gpio_unexport(PIN)) {
return 1;
}
return 0;
}
// python function setup(channel, direction, pull_up_down=PUD_OFF, initial=None)
static PyObject *py_setup_channel(PyObject *self, PyObject *args, PyObject *kwargs)
{
unsigned int gpio;
int channel, direction;
int pud = PUD_OFF + PY_PUD_CONST_OFFSET;
int initial = -1;
static char *kwlist[] = {"channel", "direction", "pull_up_down", "initial", NULL};
int func;
if (!PyArg_ParseTupleAndKeywords(args, kwargs, "ii|ii", kwlist, &channel, &direction, &pud, &initial))
return NULL;
// check module has been imported cleanly
if (setup_error)
{
PyErr_SetString(PyExc_RuntimeError, "Module not imported correctly!");
return NULL;
}
// run init_module if module not set up
if (!module_setup && (init_module() != SETUP_OK))
return NULL;
if (get_gpio_number(channel, &gpio))
return NULL;
if (direction != INPUT && direction != OUTPUT)
{
PyErr_SetString(PyExc_ValueError, "An invalid direction was passed to setup()");
return NULL;
}
if (direction == OUTPUT)
pud = PUD_OFF + PY_PUD_CONST_OFFSET;
pud -= PY_PUD_CONST_OFFSET;
if (pud != PUD_OFF && pud != PUD_DOWN && pud != PUD_UP)
{
PyErr_SetString(PyExc_ValueError, "Invalid value for pull_up_down - should be either PUD_OFF, PUD_UP or PUD_DOWN");
return NULL;
}
func = gpio_function(gpio);
if (gpio_warnings && // warnings enabled and
((func != 0 && func != 1) || // (already one of the alt functions or
(gpio_direction[gpio] == -1 && func == 1))) // already an output not set from this program)
{
PyErr_WarnEx(NULL, "This channel is already in use, continuing anyway. Use GPIO.setwarnings(False) to disable warnings.", 1);
}
if (direction == OUTPUT && (initial == LOW || initial == HIGH))
{
output_gpio(gpio, initial);
}
setup_gpio(gpio, direction, pud);
gpio_direction[gpio] = direction;
Py_RETURN_NONE;
}
void
irpause()
{
struct timespec ts = { .tv_sec = 0, .tv_nsec = 450000 };
while(nanosleep(&ts, &ts) < 0 && errno == EINTR) ;
}
void
write_byte(uint8_t byte)
{
for(int i = 0; i < 8; i++) {
if(byte & 1) {
output_gpio(gpio_pin, HIGH);
}
irpause();
if(byte & 1) {
output_gpio(gpio_pin, LOW);
}
irpause();
byte >>= 1;
}
}
int
main(int argc, const char** argv)
{
if(argc < 2 || !(gpio_pin = atoi(argv[1]))) {
fprintf(stderr, "usage: irtx <gpio pin>\n");
}
if(setup() != SETUP_OK) {
fprintf(stderr, "could not set up GPIO\n");
}
setup_gpio(gpio_pin, OUTPUT, PUD_OFF);
write_byte('X');
cleanup();
}
// python function setup(channel, direction, pull_up_down=PUD_OFF, initial=None)
static PyObject *py_setup_channel(PyObject *self, PyObject *args, PyObject *kwargs)
{
unsigned int gpio;
int channel, direction;
int pud = PUD_OFF;
int initial = -1;
static char *kwlist[] = {"channel", "direction", "pull_up_down", "initial", NULL};
int func;
if (!PyArg_ParseTupleAndKeywords(args, kwargs, "ii|ii", kwlist, &channel, &direction, &pud, &initial))
return NULL;
if (get_gpio_number(channel, &gpio))
return NULL;
if (direction != INPUT && direction != OUTPUT)
{
PyErr_SetString(InvalidDirectionException, "An invalid direction was passed to setup()");
return NULL;
}
if (direction == OUTPUT)
pud = PUD_OFF;
if (pud != PUD_OFF && pud != PUD_DOWN && pud != PUD_UP)
{
PyErr_SetString(InvalidPullException, "Invalid value for pull_up_down - should be either PUD_OFF, PUD_UP or PUD_DOWN");
return NULL;
}
func = gpio_function(gpio);
if (gpio_warnings && // warnings enabled and
((func != 0 && func != 1) || // (already one of the alt functions or
(gpio_direction[gpio] == -1 && func == 1))) // already an output not set from this program)
{
PyErr_WarnEx(NULL, "This channel is already in use, continuing anyway. Use GPIO.setwarnings(False) to disable warnings.", 1);
}
// printf("Setup GPIO %d direction %d pud %d\n", gpio, direction, pud);
if (direction == OUTPUT && (initial == LOW || initial == HIGH))
{
// printf("Writing intial value %d\n",initial);
output_gpio(gpio, initial);
}
setup_gpio(gpio, direction, pud);
gpio_direction[gpio] = direction;
Py_INCREF(Py_None);
return Py_None;
}
// python function setup(channel, direction, pull_up_down=PUD_OFF, initial=None)
static PyObject *py_setup_channel(PyObject *self, PyObject *args, PyObject *kwargs)
{
unsigned int gpio;
int channel, direction;
unsigned int sys_gpio;
int pud = PUD_OFF + PY_PUD_CONST_OFFSET;
static char *kwlist[] = {"channel", "direction", "pull_up_down", "initial", NULL};
int initial = -1;
if (!PyArg_ParseTupleAndKeywords(args, kwargs, "ii|ii", kwlist, &channel, &direction, &pud, &initial))
return NULL;
// check module has been imported cleanly
if (setup_error)
{
PyErr_SetString(PyExc_RuntimeError, "Module not imported correctly!");
return NULL;
}
if (get_gpio_number(channel, &gpio, &sys_gpio)){
return NULL;
}
if (direction != INPUT && direction != OUTPUT)
{
PyErr_SetString(PyExc_ValueError, "An invalid direction was passed to setup()");
return NULL;
}
if (direction == OUTPUT)
pud = PUD_OFF + PY_PUD_CONST_OFFSET;
pud -= PY_PUD_CONST_OFFSET;
if (pud != PUD_OFF && pud != PUD_DOWN && pud != PUD_UP)
{
PyErr_SetString(PyExc_ValueError, "Invalid value for pull_up_down - should be either PUD_OFF, PUD_UP or PUD_DOWN");
return NULL;
}
if (direction == OUTPUT && (initial == LOW || initial == HIGH))
{
output_gpio(gpio, initial);
}
setup_gpio(gpio, direction, pud);
gpio_direction[sys_gpio] = direction;
Py_RETURN_NONE;
}
// python function output(channel, value)
static PyObject *py_output_gpio(PyObject *self, PyObject *args)
{
int gpio, channel, value;
if (!PyArg_ParseTuple(args, "ii", &channel, &value))
return NULL;
if (gpio_mode != BOARD && gpio_mode != BCM)
{
PyErr_SetString(ModeNotSetException, "Please set mode using GPIO.setmode(GPIO.BOARD) or GPIO.setmode(GPIO.BCM)");
return NULL;
}
if ( (gpio_mode == BCM && (channel < 0 || channel > 53))
|| (gpio_mode == BOARD && (channel < 1 || channel > 26)) )
{
PyErr_SetString(InvalidChannelException, "The channel sent is invalid on a Raspberry Pi");
return NULL;
}
if (gpio_mode == BOARD)
{
gpio = pin_to_gpio[channel];
if (gpio == -1)
{
PyErr_SetString(InvalidChannelException, "The channel sent is invalid on a Raspberry Pi");
return NULL;
}
}
else // gpio_mode == BCM
{
gpio = channel;
}
if (gpio_direction[gpio] != OUTPUT)
{
PyErr_SetString(WrongDirectionException, "The GPIO channel has not been set up or is set up in the wrong direction");
return NULL;
}
// printf("Output GPIO %d value %d\n", gpio, value);
output_gpio(gpio, value);
Py_INCREF(Py_None);
return Py_None;
}
// python function output(channel, value) without direction check
static PyObject*
py_forceoutput_gpio(PyObject *self, PyObject *args)
{
int gpio, channel, value;
if (!PyArg_ParseTuple(args, "ii", &channel, &value))
return NULL;
// printf("Output GPIO %d value %d\n", gpio, value);
if ((gpio = channel_to_gpio(channel)) < 0)
return NULL;
output_gpio(gpio, value);
Py_INCREF(Py_None);
return Py_None;
}
// python function output(channel, value)
static PyObject *py_output_gpio(PyObject *self, PyObject *args)
{
unsigned int gpio;
int channel, value;
if (!PyArg_ParseTuple(args, "ii", &channel, &value))
return NULL;
if (get_gpio_number(channel, &gpio))
return NULL;
if (gpio_direction[gpio] != OUTPUT)
{
PyErr_SetString(PyExc_RuntimeError, "The GPIO channel has not been set up as an OUTPUT");
return NULL;
}
output_gpio(gpio, value);
Py_RETURN_NONE;
}
// python function output(channel, value)
static PyObject*
py_output_gpio(PyObject *self, PyObject *args)
{
int gpio, channel, value;
if (!PyArg_ParseTuple(args, "ii", &channel, &value))
return NULL;
if ((gpio = channel_to_gpio(channel)) < 0)
return NULL;
if (gpio_direction[gpio] != OUTPUT) {
PyErr_SetString(WrongDirectionException, "The GPIO channel has not been set up as an OUTPUT");
return NULL;
}
// printf("Output GPIO %d value %d\n", gpio, value);
output_gpio(gpio, value);
Py_INCREF(Py_None);
return Py_None;
}