Revision 0:0f53e5add603, committed 2018-07-23

Comitter:

JackB

Date:

Mon Jul 23 12:25:17 2018 +0000

Commit message:

PCA9745

Changed in this revision

diff -r 000000000000 -r 0f53e5add603 PCA9745B.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PCA9745B.cpp	Mon Jul 23 12:25:17 2018 +0000
@@ -0,0 +1,53 @@
+#include "mbed.h"
+#include "stdint.h"
+#include "PCA9745B.h"
+
+PCA9745B::PCA9745B(uint8_t number, PinName SCLK, PinName MOSI) : n(number), spi(MOSI, NC, SCLK)
+{
+    numdrivers = n;   
+    
+    // Configure SPI to 8 bits and SPI_SPEED  
+    spi.format(8, 0);
+    spi.frequency(SPI_SPEED);
+    
+    BCr = BCg = BCb = 0x7F;
+    pwmbuffer = (uint16_t *)calloc(2, 12*n);
+}
+
+void PCA9745B::write(void) {
+  uint32_t command;
+  // Magic word for write
+  command = 0x25;
+  command <<= 5;
+  //OUTTMG = 1, EXTGCK = 0, TMGRST = 1, DSPRPT = 1, BLANK = 0 -> 0x16
+  command |= 0x16;
+  command <<= 7;
+  command |= BCr;
+  command <<= 7;
+  command |= BCg;
+  command <<= 7;
+  command |= BCb;
+  for (uint8_t n=0; n<numdrivers; n++) {
+    spi.write(command >> 24);
+    spi.write(command >> 16);
+    spi.write(command >> 8);
+    spi.write(command);
+    // 12 channels per PCA9745B
+    for (int8_t c=11; c >= 0 ; c--) {
+      // 16 bits per channel, send MSB first
+      spi.write(pwmbuffer[n*12+c]>>8);
+      spi.write(pwmbuffer[n*12+c]);
+    }
+  }
+}
+
+void PCA9745B::setPWM(uint8_t chan, uint16_t pwm) {
+  if (chan > 12*numdrivers) return;
+  pwmbuffer[chan] = pwm;  
+}
+
+void PCA9745B::setLED(uint8_t lednum, uint16_t r, uint16_t g, uint16_t b) {
+  setPWM(lednum*3, r);
+  setPWM(lednum*3+1, g);
+  setPWM(lednum*3+2, b);
+}

diff -r 000000000000 -r 0f53e5add603 PCA9745B.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PCA9745B.h	Mon Jul 23 12:25:17 2018 +0000
@@ -0,0 +1,69 @@
+#ifndef PCA9745B_H
+#define PCA9745B_H
+
+/**
+  * SPI speed used by the mbed to communicate with the PCA9745B
+  * The PCA9745B supports up to 10Mhz.
+  */
+#define SPI_SPEED 1000000
+
+/**
+  *  Using the TLC5 class to control an LED:
+  *  @code
+  *  #include "mbed.h"
+  *  #include "PCA9745B.h"
+  *  
+  *  // Create the TLC5711 instance
+  *  PCA9745B tlc(1, p7, p5);
+  *  
+  *  int main()
+  *  {   
+  *      
+  *      while(1)
+  *      {
+  *         // Led1 -> R0
+  *         tlc.setLED(0, 65535, 0, 0);
+  *         tlc.write( );
+  *         tlc.setLED(1, 0, 0, 0);
+  *         tlc.write( );
+  *         tlc.setLED(2, 0, 0, 0);
+  *         tlc.write( );
+  *         tlc.setLED(3, 0, 0, 0);
+  *         tlc.write( );
+  *         wait( 1 );
+  *  
+  *      }
+  *  }
+  *  @endcode
+  */
+
+ class PCA9745B
+{
+
+public:/**
+      *  Set up the PCA9745B
+      *  @param SCLK - The SCK pin of the SPI bus
+      *  @param MOSI - The MOSI pin of the SPI bus
+      *  @param number - The number of PCA9745Bs 
+      */
+  
+    PCA9745B(uint8_t number, PinName SCLK, PinName MOSI);
+
+  void setPWM(uint8_t chan, uint16_t pwm);
+  void setLED(uint8_t lednum, uint16_t r, uint16_t g, uint16_t b);
+  void write(void);    
+        
+  uint8_t n;
+  
+  private:
+  
+  SPI spi;
+  
+  uint16_t *pwmbuffer;
+
+  uint8_t BCr, BCg, BCb;
+  int8_t numdrivers;
+
+};
+ 
+#endif