Basic multiplexing (use equalizer.py when music is playing, rainbow.py otherwise)

host_python/init.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+mkdir -p /tmp/ledbar
+rm -f /tmp/ledbar/rainbow /tmp/ledbar/equalizer /tmp/ledbar/serial
+
+mkfifo /tmp/ledbar/equalizer
+mkfifo /tmp/ledbar/rainbow
+mkfifo /tmp/ledbar/serial
+
+while true; do
+	echo "Starting rainbow"
+	./rainbow.py -s > /tmp/ledbar/rainbow
+done &
+
+while true; do
+	echo "Starting equalizer"
+	./equalizer.py -s > /tmp/ledbar/equalizer
+done &
+
+while true; do
+	echo "Starting serial writer"
+	./send_to_serial.py /dev/ttyUSB0 < /tmp/ledbar/serial
+done &
+
+echo "Starting multiplexer"
+../multiplexer/mux &
+wait

mux/mux.c

@@ -0,0 +1,93 @@
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+
+#define READS_THR	20
+#define RAINBOW_DIVISOR 30
+
+int main() {
+	int rainbow, equalizer, serial;
+	fd_set readers;
+	struct timeval tv;
+	int r,s,w;
+	int reads_eq=0, reads_ra=0;
+	int source;
+	char buf_eq[65], buf_ra[65];
+	char *srcbuf=buf_eq;
+
+
+	rainbow=open("/tmp/ledbar/rainbow", O_RDWR);
+	equalizer=open("/tmp/ledbar/equalizer", O_RDWR);
+	serial=open("/tmp/ledbar/serial", O_RDWR);
+
+	if(rainbow==-1 || equalizer==-1 || serial==-1) {
+		perror("Open failed");
+		return 1;
+	}
+
+	while(1) {
+		tv.tv_sec=3;
+		tv.tv_usec=0;
+		FD_ZERO(&readers);
+		FD_SET(rainbow, &readers);
+		FD_SET(equalizer, &readers);
+		s=select(equalizer+1, &readers, NULL, NULL, &tv);
+		if(s==-1) {
+			perror("select failed");
+			return 2;
+		} else if(s) {
+			if(FD_ISSET(equalizer, &readers)) {
+				r=read(equalizer, buf_eq, sizeof(buf_eq)-1);
+				if(r==-1) {
+					perror("eq read");
+					return 3;
+				}
+				int i;
+				for(i=0; i<r; i++) {
+					if(buf_eq[i]) {
+						reads_eq++;
+						break;
+					}
+				}
+			}
+			if(FD_ISSET(rainbow, &readers)) {
+				r=read(rainbow, buf_ra, sizeof(buf_ra)-1);
+				if(r==-1) {
+					perror("ra read");
+					return 3;
+				}
+				reads_ra++;
+			}
+					
+	//	printf("eq: %i ra: %i r: %i\n", reads_eq, reads_ra, r);
+
+			if(reads_eq>READS_THR) {
+				reads_eq=0;
+				reads_ra=0;
+				if(srcbuf!=buf_eq)
+					printf("switching to equalizer\n");
+				srcbuf=buf_eq;
+			} else if(reads_ra>READS_THR*RAINBOW_DIVISOR) {
+				reads_eq=0;
+				reads_ra=0;
+				if(srcbuf!=buf_ra)
+					printf("switching to rainbow\n");
+				srcbuf=buf_ra;
+			}
+	
+			if(write(serial, srcbuf, r)==-1) {
+				perror("write failed");
+				return 4;
+			}
+	//		usleep(500);
+
+		}
+	}
+	close(serial);
+	close(rainbow);
+	close(equalizer);
+	return 0;
+}
+