David Knight / PololuLedStrip

This library lets you control the addressable RGB LED strips from Pololu Robotics. Forked to add selectable colour order (Support RGB or GRB Leds)

Fork of PololuLedStrip by David Grayson

PololuLedStrip.cpp@4:d3b60bd43811, 2013-02-28 (annotated)

Committer:
DavidEGrayson
Date:
Thu Feb 28 00:42:44 2013 +0000
Revision:
4:d3b60bd43811
Parent:
1:102307d9b701
Child:
6:9d0530b7dae2
Proof of the concept that we can achieve variable delays by jumping into a particular portion of a large subroutine with noops.

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 1:102307d9b701 8 PololuLedStrip::PololuLedStrip(PinName pinName)
DavidEGrayson 1:102307d9b701 9 {
DavidEGrayson 1:102307d9b701 10 gpio_init(&gpio, pinName, PIN_OUTPUT);
DavidEGrayson 1:102307d9b701 11 }
DavidEGrayson 1:102307d9b701 12
DavidEGrayson 1:102307d9b701 13 void PololuLedStrip::write(rgb_color * colors, unsigned int count)
DavidEGrayson 1:102307d9b701 14 {
DavidEGrayson 1:102307d9b701 15 __disable_irq(); // Disable interrupts temporarily because we don't want our pulse timing to be messed up.
DavidEGrayson 1:102307d9b701 16
DavidEGrayson 1:102307d9b701 17 while(count--)
DavidEGrayson 1:102307d9b701 18 {
DavidEGrayson 1:102307d9b701 19 led_strip_write_color(colors++, gpio.reg_set, gpio.reg_clr, gpio.mask);
DavidEGrayson 1:102307d9b701 20
DavidEGrayson 1:102307d9b701 21 if (interruptFriendly)
DavidEGrayson 1:102307d9b701 22 {
DavidEGrayson 1:102307d9b701 23 __enable_irq();
DavidEGrayson 1:102307d9b701 24 __nop();
DavidEGrayson 1:102307d9b701 25 __nop();
DavidEGrayson 1:102307d9b701 26 __nop();
DavidEGrayson 1:102307d9b701 27 __disable_irq();
DavidEGrayson 1:102307d9b701 28 }
DavidEGrayson 1:102307d9b701 29 }
DavidEGrayson 1:102307d9b701 30
DavidEGrayson 1:102307d9b701 31 __enable_irq(); // Re-enable interrupts now that we are done.
DavidEGrayson 1:102307d9b701 32 wait_us(24); // Hold the line low for 24 microseconds to send the reset signal.
DavidEGrayson 1:102307d9b701 33 }