Push minimum PWM value mgmt into rgb module

[rgblamp.git] / rgb.h

diff --git a/rgb.h b/rgb.h
index b2149edfaffd1786bf89066bfeb0bce5084495e3..7dc0da38f13e9742643bd88d5f1e6019900537e0 100644 (file)
--- 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