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/**
* @example rc_calibrate_escs.c
*
* Typical brushless speed controllers (ESCs) accept a variety of pulse widths,
* usually from 900-2100 microseconds. Before using them, you must calibrate the
* ESC so it knows what pulse widths correspond to minimum and maximum throttle.
* Typically ESCs go into calibration mode by applying any pulse width greater
* than roughly 1000us when it is powered on. Once in calibration mode, the user
* then applies max and min pulse widths briefly before turning off the signal
* to exit calibration mode. This is typically done with the throttle stick on
* your RC transmitter.
*
* The rc_calibrate_escs example assists you with this process by sending the
* right pulse widths. Follow the instructions that are displayed in the console
* when you execute the program.
*/
#include <stdio.h>
#include <rc/servo.h>
#include <rc/pthread.h>
#include <rc/time.h>
static int running;
static float width; // global variable for normalized pulse width to send
// background thread to send pulses at 50hz to ESCs
static void* __send_pulses(__attribute__ ((unused)) void *params)
{
while(running){
rc_servo_send_esc_pulse_normalized(0, width);
rc_usleep(20000);
}
return 0;
}
int main()
{
pthread_t send_pulse_thread;
//char c;
if(rc_servo_init()==-1) return -1;
printf("\nDISCONNECT PROPELLERS FROM MOTORS\n");
printf("DISCONNECT POWER FROM ESCS\n");
printf("press enter to start sending max pulse width\n");
getchar();
//Send full throttle until the user hits enter
width = 1;
running = 1;
if(rc_pthread_create(&send_pulse_thread, __send_pulses, (void*) NULL, SCHED_OTHER,0)==-1){
return -1;
}
printf("\n");
printf("Now apply power to the ESCs.\n");
printf("Press enter again after the ESCs finish chirping\n");
getchar();
// now set lower bound
printf("\n");
printf("Sending minimum width pulses\n");
printf("Press enter again after the ESCs chirp to finish calibration\n");
width = 0;
getchar();
// cleanup and close
printf("\nCalibration complete, check with rc_test_escs\n");
running =0;
rc_pthread_timed_join(send_pulse_thread, NULL, 1.0); // wait for it to stop
rc_servo_cleanup();
return 0;
}