Joel Rosiene / APA102

Routines to drive a chain of APA102 Leds.

Dependents:   blink_led_threading

The APA102 is an LED with a built in pwm driver which can be drive by SPI.

An array of Intensity, Red, Green, Blue values packed in to integers is displayed on a strip of APA102 elements.

The array is characterized by Rows, (active) Columns, Offset, Stride, and flags which determine how to traverse the data.

To support scrolling messages, it is possible to allocate an array which is Rows x Stride in size, and use offset to "scroll" the message. The Wrap flag is used to allow the index into the array to wrap back to zero.

To support the physical construction of arrays, the zigzag flag is used to cause the display order of odd rows to be reversed. For a 3x3 array the values are displayed in the following order is zigzag is set.

1 2 3
6 5 4
7 8 9

This allows the 3rd element to be wired to the fourth element, shortening the length of the wires on the array.

APA102.h@2:b8dc9a84801c, 2015-03-11 (annotated)

Committer:
rosienej
Date:
Wed Mar 11 14:25:18 2015 +0000
Revision:
2:b8dc9a84801c
Parent:
1:ce2f23241f88 
Formatting and docs

Who changed what in which revision?

UserRevisionLine numberNew contents of line
rosienej 0:2fd584b4a9b8 1 #ifndef MBED_APA102_H
rosienej 0:2fd584b4a9b8 2
rosienej 0:2fd584b4a9b8 3 #define MBED_PING_H
rosienej 0:2fd584b4a9b8 4
rosienej 0:2fd584b4a9b8 5 #include "mbed.h"
rosienej 0:2fd584b4a9b8 6
rosienej 2:b8dc9a84801c 7
rosienej 2:b8dc9a84801c 8
rosienej 2:b8dc9a84801c 9 /** Create an APA102 Object
rosienej 2:b8dc9a84801c 10 */
rosienej 0:2fd584b4a9b8 11 class APA102{
rosienej 0:2fd584b4a9b8 12 public:
rosienej 1:ce2f23241f88 13 /** Create an APA102 object connected to the specified mosi,miso,sclk pins
rosienej 0:2fd584b4a9b8 14 *
rosienej 0:2fd584b4a9b8 15 * @param mosi : SPI Master Out Slave In pin
rosienej 0:2fd584b4a9b8 16 * @param miso : SPI Master In Slave Out pin (ignored)
rosienej 0:2fd584b4a9b8 17 * @param sclk : SPI Clock
rosienej 0:2fd584b4a9b8 18 * @param rate : SPI Rate
rosienej 0:2fd584b4a9b8 19 */
rosienej 0:2fd584b4a9b8 20 APA102(PinName mosi,PinName miso,PinName sclk,int rate);
rosienej 0:2fd584b4a9b8 21
rosienej 1:ce2f23241f88 22 /** Set the Buffer
rosienej 0:2fd584b4a9b8 23 *
rosienej 0:2fd584b4a9b8 24 * @param buffer[] : a buffer of unsigned integers (4 bytes) *Rows*Stride in size
rosienej 0:2fd584b4a9b8 25 * @param Rows : Number of Rows
rosienej 0:2fd584b4a9b8 26 * @param Cols : Number of Columns
rosienej 0:2fd584b4a9b8 27 * @param Stride : The actual number of columns (useful for data alignment)
rosienej 0:2fd584b4a9b8 28 * @param Offset : The offset into a row
rosienej 0:2fd584b4a9b8 29 * @param ZigZag : A boolean, do we alternate count up/ count down per row?
rosienej 0:2fd584b4a9b8 30 * @param Wrap : A boolean, do we wrap if (Offset+Cols) > Stride? (handy for scrolling messages)
rosienej 0:2fd584b4a9b8 31 */
rosienej 0:2fd584b4a9b8 32 void SetBuffer(unsigned int Buffer[],int Rows,int Cols, int Stride,int Offset, bool ZigZag,bool Wrap);
rosienej 0:2fd584b4a9b8 33
rosienej 1:ce2f23241f88 34 /** Repaint the Strip
rosienej 0:2fd584b4a9b8 35 *
rosienej 0:2fd584b4a9b8 36 * @param none
rosienej 0:2fd584b4a9b8 37 */
rosienej 0:2fd584b4a9b8 38 void Repaint();
rosienej 0:2fd584b4a9b8 39
rosienej 2:b8dc9a84801c 40 /** Create an IRGB helper function to construct a 4 byte LED Frame
rosienej 2:b8dc9a84801c 41 *
rosienej 2:b8dc9a84801c 42 * @param I : 5 bits of intensity (0,1,2,...,31)
rosienej 2:b8dc9a84801c 43 * @param R : 8 bits of Red (0,1,...,255)
rosienej 2:b8dc9a84801c 44 * @param G : 8 bits of Green (0,1,...,255)
rosienej 2:b8dc9a84801c 45 * @param B : 8 bits of Blue (0,1,...,255)
rosienej 2:b8dc9a84801c 46 */
rosienej 2:b8dc9a84801c 47
rosienej 2:b8dc9a84801c 48 int IRGB(unsigned char I,unsigned char R,unsigned char G,unsigned char B) {
rosienej 2:b8dc9a84801c 49 return ((0xE0 + 0x1F&I)<<24)|((0xFF&R)<<16)|((0xFF&G)<<8)|(0xFF&B);}
rosienej 2:b8dc9a84801c 50
rosienej 0:2fd584b4a9b8 51 protected:
rosienej 2:b8dc9a84801c 52
rosienej 0:2fd584b4a9b8 53 SPI _spi;
rosienej 0:2fd584b4a9b8 54 private:
rosienej 0:2fd584b4a9b8 55 int NR;
rosienej 0:2fd584b4a9b8 56 int NC;
rosienej 0:2fd584b4a9b8 57 int NS;
rosienej 0:2fd584b4a9b8 58 int off;
rosienej 0:2fd584b4a9b8 59 bool ZF;
rosienej 0:2fd584b4a9b8 60 bool WF;
rosienej 0:2fd584b4a9b8 61 unsigned int * Buf;
rosienej 0:2fd584b4a9b8 62 };
rosienej 0:2fd584b4a9b8 63
rosienej 0:2fd584b4a9b8 64 #endif