Add README

[rgblamp.git] / rgb.h

diff --git a/rgb.h b/rgb.h
index b2149edfaffd1786bf89066bfeb0bce5084495e3..a904bd59eb3ff8c813a575609ba6defe27208fad 100644 (file)
--- a/rgb.h
+++ b/rgb.h
@@ -1,3 +1,32 @@
+/*
+ * Copyright © 2011, 2012, Titanium Mirror, Inc..
+ * All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - Neither the name of Titanium Mirror, Inc. nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
+ * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
 /*
  * File:   rgb.h
  *
@@ -14,6 +43,8 @@
 #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 +58,46 @@ 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