From bfc60b6b0d850e8812a3d641cf435d926f4ad1f0 Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Sun, 20 Feb 2022 00:20:17 +0100
Subject: [PATCH] DMX: Better daemon

---
 MQTT                     |  4 ++--
 dmx/daemon/Makefile      |  2 +-
 dmx/daemon/burrow-dmxd.c | 51 ++++++++++++++++++++++++++++------------
 3 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/MQTT b/MQTT
index c2f2c0a..7f485bb 100644
--- a/MQTT
+++ b/MQTT
@@ -51,8 +51,8 @@ burrow/heating/water/active	0/1
 burrow/heating/error		[error code from message 0500:006b in decimal]
 burrow/heating/clock		yyyy-mm-ddThh:mm
 
-burrow/lights/catarium/top	0-255 [warm] 0-255 [cold]
-burrow/lights/catarium/bottom	0-255 [warm] 0-255 [cold]
+burrow/lights/catarium/top	0-1 [intensity] 0-1 [warm-cold]
+burrow/lights/catarium/bottom	0-1 [intensity] 0-1 [warm-cold]
 
 bsb/stats/*
 bsb/frame			hex dump of raw frames received
diff --git a/dmx/daemon/Makefile b/dmx/daemon/Makefile
index 9ac9ef9..cc6cdd4 100644
--- a/dmx/daemon/Makefile
+++ b/dmx/daemon/Makefile
@@ -7,7 +7,7 @@ MOSQUITTO_CFLAGS := $(shell $(PC) --cflags libmosquitto)
 MOSQUITTO_LIBS := $(shell $(PC) --libs libmosquitto)
 
 CFLAGS=-O2 -Wall -Wextra -Wno-sign-compare -Wno-parentheses -Wstrict-prototypes -Wmissing-prototypes $(UCW_CFLAGS) $(USB_CFLAGS) $(MOSQUITTO_CFLAGS)
-LDLIBS=$(UCW_LIBS) $(USB_LIBS) $(MOSQUITTO_LIBS) -lpthread
+LDLIBS=$(UCW_LIBS) $(USB_LIBS) $(MOSQUITTO_LIBS) -lpthread -lm
 
 all: burrow-dmxd
 
diff --git a/dmx/daemon/burrow-dmxd.c b/dmx/daemon/burrow-dmxd.c
index 5634537..6466482 100644
--- a/dmx/daemon/burrow-dmxd.c
+++ b/dmx/daemon/burrow-dmxd.c
@@ -10,6 +10,7 @@
 #include <ucw/string.h>
 #include <ucw/unaligned.h>
 
+#include <math.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdint.h>
@@ -31,7 +32,8 @@ typedef unsigned int uint;
 
 static mtx_t light_mutex;
 static cnd_t light_cond;
-static byte light_pwm[4];
+static double light_brightness[2];
+static double light_temperature[2];
 static bool light_refresh;
 
 /*** MQTT ***/
@@ -86,23 +88,23 @@ static void mqtt_msg_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, c
 	msg(L_DEBUG, "MQTT < %s %s", m->topic, val);
 
 	int index;
-	if (!strcmp(m->topic, "burrow/lights/catarium/top"))
+	if (!strcmp(m->topic, "burrow/lights/catarium/bottom"))
 		index = 0;
-	else if (!strcmp(m->topic, "burrow/lights/catarium/bottom"))
+	else if (!strcmp(m->topic, "burrow/lights/catarium/top"))
 		index = 1;
 	else
 		return;
 
-	int warm, cold;
-	if (sscanf(val, "%d%d", &warm, &cold) != 2 ||
-	    !(warm >= 0 && warm < 256 && cold >= 0 && cold < 256)) {
+	double bright, temp;
+	if (sscanf(val, "%lf%lf", &bright, &temp) != 2 ||
+	    !(bright >= 0 && bright <= 1 && temp >= 0 && temp <= 1)) {
 		msg(L_ERROR, "Invalid value of %s: %s", m->topic, val);
 		return;
 	}
 
 	mtx_lock(&light_mutex);
-	light_pwm[2*index] = warm;
-	light_pwm[2*index + 1] = cold;
+	light_brightness[index] = bright;
+	light_temperature[index] = temp;
 	light_refresh = 1;
 	cnd_broadcast(&light_cond);
 	mtx_unlock(&light_mutex);
@@ -194,7 +196,30 @@ static void init_usb(void)
 	open_device();
 }
 
-/*** Protocol ***/
+/*** DMX ***/
+
+static byte dmx_packet[5];
+
+static int dmx_build_packet(void)
+{
+	byte *pkt = dmx_packet;
+	pkt[0] = 0;
+
+	for (int i=0; i < 2; i++) {
+		double r = 2;
+		double x = (exp(r*light_brightness[i]) - 1) / (exp(r) - 1);
+		double t = light_temperature[i];
+		double w = 2*x*(1-t);
+		double c = 2*x*t;
+		pkt[2*i + 1] = CLAMP((int)(255*w), 0, 255);
+		pkt[2*i + 2] = CLAMP((int)(255*c), 0, 255);
+	}
+
+	return sizeof(dmx_packet);
+}
+
+
+/*** Main ***/
 
 static int use_daemon;
 static int use_debug;
@@ -245,11 +270,7 @@ int main(int argc UNUSED, char **argv)
 		while (!need_resend && !light_refresh)
 			cnd_wait(&light_cond, &light_mutex);
 
-		byte packet[5];
-		int len = sizeof(packet);
-		packet[0] = 0;
-		memcpy(packet + 1, light_pwm, 4);
-	
+		int len = dmx_build_packet();
 		light_refresh = 0;
 		need_resend = 0;
 		mtx_unlock(&light_mutex);
@@ -257,7 +278,7 @@ int main(int argc UNUSED, char **argv)
 		msg(L_DEBUG, "Sending DMX packet");
 
 		int err, transferred;
-		if (err = libusb_bulk_transfer(devh, 0x01, packet, len, &transferred, 1000))
+		if (err = libusb_bulk_transfer(devh, 0x01, dmx_packet, len, &transferred, 1000))
 			usb_error("USB transfer failed: error %d", err);
 		else if (transferred != len)
 			usb_error("USB short transfer: %d out of %d bytes", transferred, len);
-- 
2.39.2