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

Committer:
DavidEGrayson
Date:
2013-03-01
Revision:
9:6ffb85d69eaf
Parent:
8:1578776ceac5
Child:
10:f1bb84b97788

File content as of revision 9:6ffb85d69eaf:

#include "PololuLedStrip.h"

bool PololuLedStrip::interruptFriendly = false;

uint8_t led_strip_write_delays[3];

void PololuLedStrip::calculateDelays()
{
    // Get the clock frequency in MHz.
    int f_mhz = SystemCoreClock / 1000000;
    
    // Arrange for a 700 nanosecond delay between the rise time and the fall time for a 0 bit.
    led_strip_write_delays[0] = 700*f_mhz/1000 - 25 - 5;
    
    // Arrange for a 600 nanosecond delay between the fall time for a 0 bit and the fall time for a 1 bit.
    // This means the pulses representing a 1 will be 700+600 = 1300 nanoseconds.
    led_strip_write_delays[1] = 600*f_mhz/1000 - 19;
    
    // Arrange for a 1200 nanosecond delay between the fall time for a 1 bit and rise time of the next bit.
    // This means the period of the signal will be 2500 nanoseconds.
    led_strip_write_delays[2] = 1200*f_mhz/1000 - 24;
}

PololuLedStrip::PololuLedStrip(PinName pinName)
{
    gpio_init(&gpio, pinName, PIN_OUTPUT);
}

void PololuLedStrip::write(rgb_color * colors, unsigned int count)
{
    calculateDelays();

    __disable_irq();   // Disable interrupts temporarily because we don't want our pulse timing to be messed up.

    while(count--)
    {
        led_strip_write_color(colors, gpio.reg_set, gpio.reg_clr, gpio.mask);
        colors++;
         
        if (interruptFriendly)
        {
            __enable_irq();
            __nop();
            __nop();
            __nop();
            __disable_irq();
        }
    }
        
    __enable_irq();   // Re-enable interrupts now that we are done.
    wait_us(24);      // Hold the line low for 24 microseconds to send the reset signal.
    
    //*(gpio.reg_set) = gpio.mask;
    //*(gpio.reg_clr) = gpio.mask;

}