Receive commands via UDP

src/main.c

@@ -1,53 +1,103 @@
 #include <math.h>
-#include <unistd.h>
+
 #include <time.h>
 #include <string.h>
 #include <errno.h>
-#include <stdio.h>
 #include <stdint.h>
 
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
 #include "../include/ws2801.h"
 #include "../include/logger.h"
 
-#define PI 3.141592654f
+#define PORT 2703
 
-void set_all(uint8_t r, uint8_t g, uint8_t b)
+#define NUM_MODULES 20
-{
-	for(uint8_t i = 0; i < 20; i++) {
-		ws2801_set_colour(i, r, g, b);
-	}
-}
 
-float sin_off(float phase)
+#define SET_COLOUR   0
-{
+#define FADE_COLOUR  1
-	return 255 * (0.5f + 0.5f * sin(phase));
+#define ADD_COLOUR   2
-}
+#define SET_FADESTEP 3
 
 int main(void)
 {
-	float phase = 0;
+	int sock;
+	socklen_t remote_addr_len;
+	struct sockaddr_in listen_addr, remote_addr;
+	uint8_t pkgbuf[256];
+	ssize_t rcvbytes, offset = 0;
 
+	uint8_t cmd, r, g, b, action, module;
+
+	// initialize logger	
 	logger_init();
 
-	if(ws2801_init(20) == -1) {
+	// initialize UDP server socket
+	sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+	if(sock == -1) {
+		LOG(LVL_FATAL, "Could not initialize UDP socket: %s.", strerror(errno));
+		return 1;
+	}
+
+	memset(&listen_addr, 0, sizeof(listen_addr));
+	listen_addr.sin_family = AF_INET;
+	listen_addr.sin_port = htons(PORT);
+	listen_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+
+	if(bind(sock, (struct sockaddr*)&listen_addr, sizeof(listen_addr)) == -1) {
+		LOG(LVL_FATAL, "Could not bind socket to port %i: %s.", PORT, strerror(errno));
+		return 1;
+	}
+
+	// initialize ws2801 library
+	if(ws2801_init(NUM_MODULES) == -1) {
 		LOG(LVL_FATAL, "Could not initialize WS2801 library.");
 		return 1;
 	}
 
+	LOG(LVL_INFO, "Initialisation complete.");
+
 
 	while(1) {
-		//phase += PI/1000;
+		remote_addr_len = sizeof(remote_addr);
+		rcvbytes = recvfrom(sock, pkgbuf, 256, 0, (struct sockaddr*)&remote_addr, &remote_addr_len);
+		if(rcvbytes == -1) {
+			LOG(LVL_ERR, "recvfrom() failed: %s. Shutting down.", strerror(errno));
+			break;
+		}
 
-		for(uint8_t i = 0; i < 20; i++) {
+		pkgbuf[rcvbytes] = 0;
-			ws2801_set_colour(i, sin_off(i * PI / 10 + phase), sin_off(i * PI / 10 + 1.241*phase), sin_off(i * PI / 10 + 1.537*phase));
+
+		// commands from packet
+		offset = 0;
+		while(offset <= rcvbytes - 3) {
+			cmd = pkgbuf[offset + 0];
+			r   = pkgbuf[offset + 1];
+			g   = pkgbuf[offset + 2];
+			b   = pkgbuf[offset + 3];
+			offset += 4;
+
+			action = (cmd & 0xC0) >> 6; // the upper 2 bits
+			module = cmd & 0x3F; // the lower 6 bits
+
+			if(action != SET_COLOUR) {
+				// action not implemented yet -> ignore
+				LOG(LVL_DEBUG, "Action %u not implemented yet.", action);
+				continue;
+			}
+
+			ws2801_set_colour(module, r, g, b);
 		}
 
 		ws2801_send_update();
-
-		static const struct timespec sleepval = {0, 40000000};
-		nanosleep(&sleepval, NULL);
 	}
 
+	close(sock);
+
 	ws2801_shutdown();
 
 	return 0;