Diff: PololuLedStrip.cpp

Revision:

7:9a088f042ee0

Parent:

6:9d0530b7dae2

Child:

8:1578776ceac5

--- a/PololuLedStrip.cpp	Fri Mar 01 00:31:24 2013 +0000
+++ b/PololuLedStrip.cpp	Fri Mar 01 01:16:48 2013 +0000
@@ -2,26 +2,26 @@
 
 bool PololuLedStrip::interruptFriendly = false;
 
-// TODO: read clock frequency from SystemCoreClock and use that to make this work on different boards.
-// calculate the three delays needed and pass them to the assembly.  The assembly can implement them with computed jumps.
+uint8_t led_strip_write_delays[3];
 
-uint8_t led_strip_write_delays[3];
+void PololuLedStrip::calculateDelays()
+{
+    int fmhz = SystemCoreClock / 1000000;
+    led_strip_write_delays[0] = 700*fmhz/1000 - 25;
+    led_strip_write_delays[1] = 600*fmhz/1000 - 19;
+    led_strip_write_delays[2] = 1200*fmhz/1000 - 24;
+}
 
 PololuLedStrip::PololuLedStrip(PinName pinName)
 {
     gpio_init(&gpio, pinName, PIN_OUTPUT);
+    calculateDelays();    // Assumption
 }
 
 void PololuLedStrip::write(rgb_color * colors, unsigned int count)
 {
     __disable_irq();   // Disable interrupts temporarily because we don't want our pulse timing to be messed up.
-    
-    int f = SystemCoreClock/1000000;
-    led_strip_write_delays[0] = 700*f/1000 - 10;
-    led_strip_write_delays[1] = 600*f/1000 - 10;
-    led_strip_write_delays[2] = 1200*f/1000 - 10;
-    led_strip_write_delays[0] = 59;
-    
+
     while(count--)
     {
         led_strip_write_color(colors++, gpio.reg_set, gpio.reg_clr, gpio.mask);