David Grayson / Mbed 2 deprecated LedStripGradient

This is an example program for the PololuLedStrip library. It generates a simple moving gradient pattern.

Dependencies:   PololuLedStrip mbed LedStripGradient

Dependents:   LedStripGradient led_phare_crf

For more information, see the PololuLedStrip library.

main.cpp

Committer:
DavidEGrayson
Date:
2013-02-26
Revision:
4:27b5c9cafe92
Parent:
3:f566eea13f49
Child:
5:8b685ba2f16b

File content as of revision 4:27b5c9cafe92:

#include "mbed.h"
#include "gpio_api.h"

namespace Pololu
{
  #ifndef _POLOLU_RGB_COLOR
  #define _POLOLU_RGB_COLOR
  typedef struct rgb_color
  {
    uint8_t red, green, blue;
  } rgb_color;
  #endif

  extern "C" int led_strip_write(rgb_color *, volatile uint32_t * set, volatile uint32_t * clear, uint32_t mask);

  class PololuLedStrip
  {
    static bool interruptFriendly;
    public:
    gpio_t gpio;
    PololuLedStrip(PinName pin);
    void write(rgb_color * colors, unsigned int count);
  };

  bool PololuLedStrip::interruptFriendly;

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

  void PololuLedStrip::write(rgb_color * colors, unsigned int count)
  {
    uint32_t pinValue = gpio.pin & 0x1F;  // Mimicing mbed/libraries/mbed/vendor/NXP/capi/gpio_api.c
    
    __disable_irq();   // Disable interrupts temporarily because we don't want our pulse timing to be messed up.
    
    while(count--)
    {
    /**
      // Send a color to the LED strip.
      // The assembly below also increments the 'colors' pointer,
      // it will be pointing to the next color at the end of this loop.
      __ASM volatile(
        "ldr r12, [%0], #3\n"   // Read the next color and advance the pointer.
        "rbit r12, r12\n"       // Reverse the order of the bits.
        "rev r12, r12\n"        // Reverse the order of the bytes.
        "mov r3, #24\n"         // Initialize the loop counter register.

        "send_led_strip_bit%=:\n"
        "str %[val], %[set]\n"            // Drive the line high.
        "rrxs r12, r12\n"                 // Rotate right through carry.
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "nop\n"
        "it cc\n" "strcc %[val], %[clear]\n"  // If the bit to send is 0, set the line low now.
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "it cs\n" "strcs %[val], %[clear]\n"  // If the bit to send is 1, set the line low now.
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"
        "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n" "nop\n"

        "sub r3, r3, #1\n"                // Decrement the loop counter.
        "cbz r3, led_strip_asm_end%=\n"   // If we have sent 24 bits, go to the end.
        "b send_led_strip_bit%=\n"
        
        "led_strip_asm_end%=:\n"

      : "=r" (colors)
      : "0" (colors),
        [set] "m" (gpio.reg_set),
        [clear] "m" (gpio.reg_clr),
        [val] "r" (pinValue)
      : "r3", "r12", "cc"
      );**/
      
      if (interruptFriendly)
      {
        __enable_irq();
        //asm volatile("nop\n");
        __disable_irq();
      }
    }
    __enable_irq();          // Re-enable interrupts now that we are done.
    //delayMicroseconds(24);  // Hold the line low for 24 microseconds to send the reset signal.
  }

}

using namespace Pololu;

DigitalOut myled(LED1);
PololuLedStrip ledStrip(LED1);

DigitalOut myled2(LED2);

int main() {
    gpio_t gpio;
    gpio_init(&gpio, LED1, PIN_OUTPUT);

    while(1) {
        myled2 = 1;
        led_strip_write(NULL, gpio.reg_set, gpio.reg_clr, 1);
        wait(0.2);
        led_strip_write(NULL, gpio.reg_set, gpio.reg_clr, 0);
        myled2 = 0;
        wait(1);
    }
}