SBUS support for BeagleBone Blue

examples/src/rc_calibrate_sbus.c

@@ -0,0 +1,36 @@
+/*
+ * @example    rc_calibrate_sbus.c
+ *
+ * Running the rc_calibrate_sbus example will print out raw data to
+ * the console and record the min and max values for each
+ * channel. These limits will be saved to disk so future sbus reads
+ * will be scaled correctly.
+ *
+ * Make sure the transmitter and receiver are paired before
+ * testing. The satellite receiver remembers which transmitter it is
+ * paired to, not your BeagleBone.
+*/
+
+#include <stdio.h>
+#include <rc/sbus.h>
+
+int main()
+{
+	printf("Please connect a SBUS satellite receiver and make sure\n");
+	printf("your transmitter is on and paired to the receiver.\n");
+	printf("\n");
+	printf("Do you want to proceed Y/N : \n");
+	char input = getchar();
+
+    if(input == 'Y' || input == 'y')
+    {
+        // run the calibration routine
+        rc_sbus_calibrate_routine();
+    }
+    else
+    {
+        printf("SBUS Calibration Program Terminated\n");
+    }
+
+	return 0;
+}

examples/src/rc_sbus_passthrough.c

@@ -0,0 +1,176 @@
+/**
+ * @example    rc_sbus_passthrough.c
+ *
+ * This sends all sbus data straight out the servo channels as they
+ * come in. When running this program the BBB acts exactly like a
+ * normal SBUS receiver.
+ *
+ * You must specify SERVO or ESC mode with -s or -e to turn on or off
+ * the 6V power rail. Sending 6V into an ESC may damage it!!!
+ *
+ * Raw data is also printed to the terminal for monitoring.
+ */
+
+#include <stdio.h>
+#include <getopt.h>
+#include <signal.h>
+#include <rc/sbus.h>
+#include <rc/servo.h>
+#include <rc/time.h>
+#include <rc/adc.h>
+
+#define BATT_VOLTAGE 6.0 // change this if using different battery
+
+static int running;
+
+typedef enum p_mode_t{
+	NONE,
+	POWERON,
+	POWEROFF
+} p_mode_t;
+
+// function to be called every time new a new SBUS packet is received.
+static void __send_pulses(void)
+{
+	int i, val;
+
+	// send single to working channels
+	for(i=1; i<=8; i++){
+		val=rc_sbus_ch_raw(i);
+		if(val>0) rc_servo_send_pulse_us(i,val);
+	}
+
+	// print all channels
+	printf("\r");
+	for(i=1;i<=RC_MAX_SBUS_ANALOG_CHANNELS;i++){
+		val = rc_sbus_ch_raw(i);
+		if (val != 0) {
+			printf("% 4d   ", val);
+		}
+	}
+	for(i=1;i<=RC_MAX_SBUS_BINARY_CHANNELS;i++){
+		printf("% 1d   ", rc_sbus_ch_binary(i));
+	}
+	fflush(stdout);
+	return;
+}
+
+// interrupt handler to catch ctrl-c
+static void __signal_handler(__attribute__ ((unused)) int dummy)
+{
+	running=0;
+	return;
+}
+
+
+// printed if some invalid argument was given
+static void __print_usage(void)
+{
+	printf("\n");
+	printf(" Options\n");
+	printf(" -s   Enable power rail for servos.\n");
+	printf(" -e   Disable power rail for ESCs.\n");
+	printf("Note: Please select only one mode at a time.\n");
+	printf(" -h   Print this messege.\n\n");
+	return;
+}
+
+// main routine
+int main(int argc, char *argv[])
+{
+	int c;
+	p_mode_t mode = NONE;
+
+	// parse arguments
+	opterr = 0;
+	while ((c = getopt(argc, argv, "seh")) != -1){
+		switch (c){
+
+		case 's': // enable power for servos
+			mode = POWERON;
+			break;
+
+		case 'e': // disbable power for ESCs
+			mode = POWEROFF;
+			break;
+
+		case 'h': // show help messege
+			__print_usage();
+			return -1;
+			break;
+
+		default:
+			fprintf(stderr,"Invalid Argument \n");
+			__print_usage();
+			return -1;
+		}
+	}
+
+	if(mode == NONE){
+		fprintf(stderr,"You must select a power mode -s or -e\n");
+		__print_usage();
+		return -1;
+	}
+
+	if(rc_sbus_init()==-1) return -1;
+
+	// if power has been requested, make sure battery is connected!
+	if(mode == POWERON){
+		// read adc to make sure battery is connected
+		if(rc_adc_init()){
+			fprintf(stderr,"ERROR: failed to run rc_adc_init()\n");
+			return -1;
+		}
+		if(rc_adc_batt()<BATT_VOLTAGE){
+			fprintf(stderr,"ERROR: battery disconnected or insufficiently charged to drive motors\n");
+			return -1;
+		}
+		rc_adc_cleanup();
+
+		if(rc_servo_init ()){
+			fprintf(stderr,"failed to initialize servos\n");
+			return -1;
+		}
+		if(rc_servo_power_rail_en(1)){
+			fprintf(stderr,"failed to enable power rail\n");
+			return -1;
+		}
+	}
+
+	// print header
+	printf("1:Thr   ");
+	printf("2:Roll  ");
+	printf("3:Pitch ");
+	printf("4:Yaw   ");
+	printf("5:Kill  ");
+	printf("6:Mode  ");
+	printf("7:Aux1  ");
+	printf("8:Aux2  ");
+	printf("\n");
+
+	printf("Waiting for SBUS Connection");
+	fflush(stdout);
+
+	// set signal handler so the loop can exit cleanly
+	signal(SIGINT, __signal_handler);
+	running=1;
+
+	rc_sbus_set_callback(&__send_pulses);
+	while(running){
+		if(rc_sbus_is_connection_active()==0){
+			printf("\rSeconds since last SBUS packet: ");
+			printf("%0.1f ", rc_sbus_nanos_since_last_packet()/1000000000.0);
+			printf("                             ");
+			fflush(stdout);
+		}
+		rc_usleep(25000);
+	}
+	printf("\n");
+
+	if(mode == POWERON){
+	  	rc_servo_cleanup ();
+	}
+	rc_sbus_cleanup();
+
+	return 0;
+}

examples/src/rc_test_sbus.c

@@ -0,0 +1,159 @@
+/**
+ * @example    rc_test_sbus.c
+ *
+ * Prints out the normalized sbus values. Make sure the transmitter
+ * and receiver are paired before testing.  The satellite receiver
+ * remembers which transmitter it is paired to, not your BeagleBone.
+ *
+ * If the values you read are not normalized between +-1, then you
+ * should run the rc_calibrate_sbus example to save your particular
+ * transmitter's min and max channel values.
+ */
+
+#include <stdio.h>
+#include <signal.h>
+#include <getopt.h>
+#include <rc/sbus.h>
+#include <rc/time.h>
+
+// possible printing modes, user selected with command line arguments
+typedef enum p_mode_t{
+	P_MODE_NONE,
+	P_MODE_RAW,
+	P_MODE_NORM
+} p_mode_t;
+
+static int running = 0;
+static p_mode_t print_mode;
+
+// printed if some invalid argument was given
+static void __print_usage(void)
+{
+	printf("\n");
+	printf("-r	print raw channel values in microseconds\n");
+	printf("-n	print normalized channel values/s\n");
+	printf("-h	print this help message\n");
+	printf("\n");
+}
+
+// interrupt handler to catch ctrl-c
+static void __signal_handler(__attribute__ ((unused)) int dummy)
+{
+	running=0;
+	return;
+}
+
+static void __new_sbus_data_callback(void)
+{
+	int i,v;
+	printf("\r");// keep printing on same line
+	// print all channels
+	if(print_mode==P_MODE_NORM){
+		for(i=0;i<RC_MAX_SBUS_ANALOG_CHANNELS;i++){
+			if (rc_sbus_ch_raw(i+1) != 0) {
+				printf("%d:% 0.2f|", i+1, rc_sbus_ch_normalized(i+1));
+			}
+		}
+	}
+	else{
+		for(i=0;i<RC_MAX_SBUS_ANALOG_CHANNELS;i++){
+			v=rc_sbus_ch_raw(i+1);
+			if (v != 0) {
+				printf("%d:%4d|", i+1, rc_sbus_ch_raw(i+1));
+			}
+		}
+	}
+	for(i=0;i<RC_MAX_SBUS_BINARY_CHANNELS;i++){
+		printf("%d:%1d|", i+RC_MAX_SBUS_ANALOG_CHANNELS+1, rc_sbus_ch_binary(i+1));
+	}
+	printf("SQ:%d|FL:%d|TE:%d",
+	       rc_sbus_signal_quality (), rc_sbus_lost_frames (), rc_sbus_total_errors ());
+	fflush(stdout);
+}
+
+int main(int argc, char *argv[])
+{
+	int c;
+	print_mode = P_MODE_NONE;
+
+	// parse arguments
+	opterr = 0;
+	while ((c = getopt(argc, argv, "rnh")) != -1){
+		switch (c){
+		case 'r':
+			if(print_mode!=P_MODE_NONE){
+				printf("\ntoo many arguments given\n");
+				__print_usage();
+				return -1;
+			}
+			print_mode = P_MODE_RAW;
+			break;
+		case 'n':
+			if(print_mode!=P_MODE_NONE){
+				printf("\ntoo many arguments given\n");
+				__print_usage();
+				return -1;
+			}
+			print_mode = P_MODE_NORM;
+			break;
+			break;
+		case 'h':
+			__print_usage();
+			return 0;
+		default:
+			fprintf(stderr,"Invalid Argument\n");
+			__print_usage();
+			return -1;
+		}
+	}
+
+	if(print_mode==P_MODE_NONE){
+		fprintf(stderr, "Please select raw or normalized mode\n");
+		__print_usage();
+		return -1;
+	}
+
+
+	if(rc_sbus_init()) return -1;
+
+	printf("\n");
+	printf("Make sure transmitter and receiver are bound and on.\n");
+	printf("If data is received, the normalized values will be printed\n");
+	printf("here along with the bit resolution and the number of channels\n");
+	printf("\n");
+	printf("If connection is lost the number of seconds since last packet\n");
+	printf("will be displayed\n");
+	printf("\n");
+
+	// set signal handler so the loop can exit cleanly
+	signal(SIGINT, __signal_handler);
+	running =1;
+
+	printf("Waiting for first packet");
+	fflush(stdout);
+	while(rc_sbus_is_new_data()==0){
+		if(running==0){
+			rc_sbus_cleanup();
+			return 0;
+		}
+		rc_usleep(50000);
+	}
+
+	// first packet arrived, set the callback and run
+	rc_sbus_set_callback(__new_sbus_data_callback);
+
+	// main loop monitor if connection is active or now
+	while(running){
+		if(rc_sbus_is_connection_active()==0){
+			printf("\rSeconds since last SBUS packet: ");
+			printf("%0.1f ", rc_sbus_nanos_since_last_packet()/1000000000.0);
+			printf("                             ");
+			fflush(stdout);
+		}
+		rc_usleep(500000);
+	}
+
+	rc_sbus_cleanup();
+	printf("\n");
+	return 0;
+}

library/CMakeLists.txt

@@ -31,6 +31,7 @@ if(DEFINED __RC_V0_3)
 		other/rc_bb_model.c
 		other/rc_cpu_freq.c
 		other/rc_dsm.c
+		other/rc_sbus.c
 		other/rc_other.c
 		other/rc_pinmux.c
 		other/rc_pru.c
@@ -52,6 +53,7 @@ else()
 		src/button.c
 		src/cpu.c
 		src/dsm.c
+		src/sbus.c
 		src/led.c
 		src/mavlink_udp.c
 		src/model.c