From 713be444bff004385f2397856be48508628c746a Mon Sep 17 00:00:00 2001
From: "R. Steve McKown" <rsmckown@gmail.com>
Date: Sat, 17 Dec 2011 11:48:42 -0700
Subject: [PATCH] Push minimum PWM value mgmt into rgb module

---
 main.c | 29 ++++++++---------------------
 rgb.h  | 41 +++++++++++++++++++++++++++++------------
 2 files changed, 37 insertions(+), 33 deletions(-)

diff --git a/main.c b/main.c
index 64cf2f1..a8f7324 100644
--- a/main.c
+++ b/main.c
@@ -144,29 +144,16 @@ signed char bright = BRIGHT_INIT;
 bit bright_up;
 signed char pbHeldCount;
 
-/* Return the constrained brightness level for use in computing RGB values */
-unsigned char bright_get()
-{
-  if (bright > BRIGHT_MAX)
-    return BRIGHT_MAX;
-  else if (bright < BRIGHT_MIN)
-    return BRIGHT_MIN;
-  else
-    return bright;
-}
-
-/* RGB values will not illuminate the LED */
+/* Combine LED color value and brightness level to generate an RGB value */
 unsigned char led_get(unsigned value)
 {
-  value = (value * bright_get()) >> 8;
-#ifdef CEIL256
-  if (value && value < 0x26)
-    return 0x26;
-#else
-  if (value && value < 4)
-    return 4;
-#endif
-  return value;
+  unsigned char tmp = bright;
+
+  if (tmp > BRIGHT_MAX)
+    tmp = BRIGHT_MAX;
+  else if (tmp < BRIGHT_MIN)
+    tmp = BRIGHT_MIN;
+  return (value * tmp) >> 8;
 }
 
 /* Set the LEDs using both color and brightness values. */
diff --git a/rgb.h b/rgb.h
index b2149ed..7dc0da3 100644
--- a/rgb.h
+++ b/rgb.h
@@ -14,6 +14,8 @@
 #define CEIL256
 #undef CEIL32
 
+#define MIN_PWM 4 /* PWM settings below this value do not illuminate the LED */
+
 /* Initialize the RGB LED assembly.  Outputs are zero, PWM is off. */
 void rgb_init();
 
@@ -27,31 +29,46 @@ void rgb_off();
 #ifdef CEIL256
 extern const unsigned char pwm_table[];
 #define rgb_set(red, grn, blu, wht) do { \
+    unsigned char tmp; \
     ndi(); /* FIXME: doesn't seem to fix flicker */ \
-    CCPR3L = pwm_table[(red)]; \
-    CCPR2L = pwm_table[(grn)]; \
-    CCPR4L = pwm_table[(blu)]; \
-    CCPR1L = pwm_table[(wht)]; \
+    tmp = pwm_table[(red)]; \
+    CCPR3L = (tmp < MIN_PWM) ? MIN_PWM : tmp; \
+    tmp = pwm_table[(grn)]; \
+    CCPR2L = (tmp < MIN_PWM) ? MIN_PWM : tmp; \
+    tmp = pwm_table[(blu)]; \
+    CCPR4L = (tmp < MIN_PWM) ? MIN_PWM : tmp; \
+    tmp = pwm_table[(wht)]; \
+    CCPR1L = (tmp < MIN_PWM) ? MIN_PWM : tmp; \
     nei(); \
 } while (0)
 #else
 #ifdef CEIL32
 extern const unsigned char pwm_table[];
 #define rgb_set(red, grn, blu, wht) do { \
+    unsigned char tmp; \
     ndi(); /* FIXME: doesn't seem to fix flicker */ \
-    CCPR3L = pwm_table[(red) >> 3]; \
-    CCPR2L = pwm_table[(grn) >> 3]; \
-    CCPR4L = pwm_table[(blu) >> 3]; \
-    CCPR1L = pwm_table[(wht) >> 3]; \
+    tmp = pwm_table[(red)] >> 3; \
+    CCPR3L = (tmp < MIN_PWM) ? MIN_PWM : tmp; \
+    tmp = pwm_table[(grn)] >> 3; \
+    CCPR2L = (tmp < MIN_PWM) ? MIN_PWM : tmp; \
+    tmp = pwm_table[(blu)] >> 3; \
+    CCPR4L = (tmp < MIN_PWM) ? MIN_PWM : tmp; \
+    tmp = pwm_table[(wht)] >> 3; \
+    CCPR1L = (tmp < MIN_PWM) ? MIN_PWM : tmp; \
     nei(); \
 } while (0)
 #else
 #define rgb_set(red, grn, blu, wht) do { \
+    unsigned char tmp; \
     ndi(); /* FIXME: doesn't seem to fix flicker */ \
-    CCPR3L = (red); \
-    CCPR2L = (grn); \
-    CCPR4L = (blu); \
-    CCPR1L = (wht); \
+    tmp = (red); \
+    CCPR3L = (tmp < MIN_PWM) ? MIN_PWM : tmp; \
+    tmp = (grn); \
+    CCPR2L = (tmp < MIN_PWM) ? MIN_PWM : tmp; \
+    tmp = (blu); \
+    CCPR4L = (tmp < MIN_PWM) ? MIN_PWM : tmp; \
+    tmp = (wht); \
+    CCPR1L = (tmp < MIN_PWM) ? MIN_PWM : tmp; \
     nei(); \
 } while (0)
 #endif
-- 
2.39.2