David Knight / PololuLedStrip

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Fork of PololuLedStrip by David Grayson

PololuLedStrip.cpp@6:9d0530b7dae2, 2013-03-01 (annotated)

Committer:
DavidEGrayson
Date:
Fri Mar 01 00:31:24 2013 +0000
Revision:
6:9d0530b7dae2
Parent:
4:d3b60bd43811
Child:
7:9a088f042ee0
Successfully read the delay amount from a table.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
DavidEGrayson 1:102307d9b701 1 #include "PololuLedStrip.h"
DavidEGrayson 1:102307d9b701 2
DavidEGrayson 1:102307d9b701 3 bool PololuLedStrip::interruptFriendly = false;
DavidEGrayson 1:102307d9b701 4
DavidEGrayson 4:d3b60bd43811 5 // TODO: read clock frequency from SystemCoreClock and use that to make this work on different boards.
DavidEGrayson 4:d3b60bd43811 6 // calculate the three delays needed and pass them to the assembly. The assembly can implement them with computed jumps.
DavidEGrayson 4:d3b60bd43811 7
DavidEGrayson 6:9d0530b7dae2 8 uint8_t led_strip_write_delays[3];
DavidEGrayson 6:9d0530b7dae2 9
DavidEGrayson 1:102307d9b701 10 PololuLedStrip::PololuLedStrip(PinName pinName)
DavidEGrayson 1:102307d9b701 11 {
DavidEGrayson 1:102307d9b701 12 gpio_init(&gpio, pinName, PIN_OUTPUT);
DavidEGrayson 1:102307d9b701 13 }
DavidEGrayson 1:102307d9b701 14
DavidEGrayson 1:102307d9b701 15 void PololuLedStrip::write(rgb_color * colors, unsigned int count)
DavidEGrayson 1:102307d9b701 16 {
DavidEGrayson 1:102307d9b701 17 __disable_irq(); // Disable interrupts temporarily because we don't want our pulse timing to be messed up.
DavidEGrayson 1:102307d9b701 18
DavidEGrayson 6:9d0530b7dae2 19 int f = SystemCoreClock/1000000;
DavidEGrayson 6:9d0530b7dae2 20 led_strip_write_delays[0] = 700*f/1000 - 10;
DavidEGrayson 6:9d0530b7dae2 21 led_strip_write_delays[1] = 600*f/1000 - 10;
DavidEGrayson 6:9d0530b7dae2 22 led_strip_write_delays[2] = 1200*f/1000 - 10;
DavidEGrayson 6:9d0530b7dae2 23 led_strip_write_delays[0] = 59;
DavidEGrayson 6:9d0530b7dae2 24
DavidEGrayson 1:102307d9b701 25 while(count--)
DavidEGrayson 1:102307d9b701 26 {
DavidEGrayson 1:102307d9b701 27 led_strip_write_color(colors++, gpio.reg_set, gpio.reg_clr, gpio.mask);
DavidEGrayson 1:102307d9b701 28
DavidEGrayson 1:102307d9b701 29 if (interruptFriendly)
DavidEGrayson 1:102307d9b701 30 {
DavidEGrayson 1:102307d9b701 31 __enable_irq();
DavidEGrayson 1:102307d9b701 32 __nop();
DavidEGrayson 1:102307d9b701 33 __nop();
DavidEGrayson 1:102307d9b701 34 __nop();
DavidEGrayson 1:102307d9b701 35 __disable_irq();
DavidEGrayson 1:102307d9b701 36 }
DavidEGrayson 1:102307d9b701 37 }
DavidEGrayson 1:102307d9b701 38
DavidEGrayson 1:102307d9b701 39 __enable_irq(); // Re-enable interrupts now that we are done.
DavidEGrayson 1:102307d9b701 40 wait_us(24); // Hold the line low for 24 microseconds to send the reset signal.
DavidEGrayson 1:102307d9b701 41 }