ardupilot/libraries/AP_HAL_Linux/RCInput_UDP.cpp

84 lines
1.9 KiB
C++

#include <inttypes.h>
#include <stddef.h>
#include <stdio.h>
#include <AP_HAL/AP_HAL.h>
#include "RCInput_UDP.h"
extern const AP_HAL::HAL& hal;
using namespace Linux;
RCInput_UDP::RCInput_UDP() :
_port(0),
_last_buf_ts(0),
_last_buf_seq(0)
{}
void RCInput_UDP::init()
{
_port = RCINPUT_UDP_DEF_PORT;
if(!_socket.bind("0.0.0.0", _port)) {
hal.console->printf("failed to bind UDP socket\n");
}
_socket.set_blocking(false);
return;
}
void RCInput_UDP::_timer_tick(void)
{
ssize_t size = -1;
unsigned int n_channels;
ssize_t header_size = offsetof(struct rc_udp_packet, pwms);
uint64_t time_delta;
uint16_t seq_delta;
/*
* Read all pending packets from udp without blocking - we may have more
* than one if we are not reading them faster than the RC is sending: only
* the last one is going to really take effect
*/
do {
ssize_t r = _socket.recv(&_buf, sizeof(_buf), 0);
if (r == -1) {
break;
}
size = r;
} while (true);
if (size < header_size) {
return;
}
/*
* v2 and v3 are compatible, with the only difference being the number
* of channels. We require at least 4 channels to be compatible with
* the upper layers and don't care about making enforcing 8 channels
* for v2
*/
n_channels = (size - header_size) / sizeof(uint16_t);
if (n_channels < 4) {
return;
}
time_delta = _buf.timestamp_us - _last_buf_ts;
if (_last_buf_ts != 0 && time_delta > 100000) {
hal.console->printf("no rc cmds received for %.2f msec\n",
time_delta / 1000.0);
}
seq_delta = _buf.sequence - _last_buf_seq;
if (seq_delta > 10) {
hal.console->printf("gap in rc cmds > 10: %u\n", seq_delta);
}
_last_buf_ts = _buf.timestamp_us;
_last_buf_seq = _buf.sequence;
_update_periods(_buf.pwms, n_channels);
}