This is a library for the PCA9685 ported from the Adafruit Ardiuno library.

Revision:
0:1ecf26e0cf3c
Child:
2:ec40a85eba51
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PCA9685Lib.cpp	Fri Feb 13 22:02:35 2015 +0000
@@ -0,0 +1,128 @@
+/*
+  This is a library for our Adafruit 16-channel PWM & Servo driver
+
+  Pick one up today in the adafruit shop!
+  ------> http://www.adafruit.com/products/815
+
+  These displays use I2C to communicate, 2 pins are required to
+  interface. For Arduino UNOs, thats SCL -> Analog 5, SDA -> Analog 4
+
+  Adafruit invests time and resources providing this open source code,
+  please support Adafruit and open-source hardware by purchasing
+  products from Adafruit!
+
+  Written by Limor Fried/Ladyada for Adafruit Industries.
+  BSD license, all text above must be included in any redistribution
+ ****************************************************/
+
+ /*****************************
+  This program was ported from https://github.com/adafruit/Adafruit-PWM-Servo-Driver-Library.
+  I also added some functions.
+  Shundo Kishi
+ */
+
+#include "PCA9685Lib.h"
+
+
+void LEDarr::operator=(uint16_t duty)
+{
+  PCALib->setDuty(LEDnum, duty);
+}
+
+PCA9685Lib::PCA9685Lib(I2C i2cobj, int addr) : _i2caddr(addr) , i2c(i2cobj)
+{
+  for(int i = 0; i<16 ; i++)
+  {
+    LED[i].PCALib = this;
+    LED[i].LEDnum = i;
+  }
+}
+
+void PCA9685Lib::i2c_probe(void)
+{
+    printf("Searching for I2C devices...\n");
+
+    int count = 0;
+    for (int address=4; address<256; address+=2) {
+        if (!i2c.write(address, NULL, 0)) { // 0 returned is ok
+            printf(" - I2C device found at address 0x%02X\r\n", address);
+            count++;
+        }
+    }
+    printf("%d devices found\r\n", count);
+}
+
+void PCA9685Lib::begin(void) {
+    reset();
+}
+
+void PCA9685Lib::setI2Cfreq(int freq) {
+    i2c.frequency(freq);
+}
+
+void PCA9685Lib::reset(void) {
+    write8(PCA9685_MODE1, 0x0);
+}
+
+void PCA9685Lib::setPrescale(uint8_t prescale) {
+    uint8_t oldmode = read8(PCA9685_MODE1);
+    uint8_t newmode = (oldmode&0x7F) | 0x10; // sleep
+    write8(PCA9685_MODE1, newmode); // go to sleep
+    wait_ms(5);
+    write8(PCA9685_PRESCALE, prescale); // set the prescaler
+    write8(PCA9685_MODE1, oldmode);
+    wait_ms(5);
+    write8(PCA9685_MODE1, oldmode | 0xa1);
+}
+
+void PCA9685Lib::setPWMFreq(float freq) {
+    //Serial.print("Attempting to set freq ");
+    //Serial.println(freq);
+    float prescaleval = 25000000;
+    prescaleval /= 4096;
+    prescaleval /= freq;
+    //Serial.print("Estimated pre-scale: "); Serial.println(prescaleval);
+    uint8_t prescale = floor(prescaleval  + 0.5) - 1;
+    //Serial.print("Final pre-scale: "); Serial.println(prescale);
+    setPrescale(prescale);
+}
+
+void PCA9685Lib::setPWM(uint8_t num, uint16_t on, uint16_t off) {
+    // hmm doesnt work, whyso?  (  Not in AI mode.  See line 54 above.  ( Works now!!  :D  )
+
+    char cmd[5];
+    cmd[0] = LED0_ON_L + 4 * num;
+    cmd[1] = on;
+    cmd[2] = on >> 8;
+    cmd[3] = off;
+    cmd[4] = off >> 8;
+    i2c.write(_i2caddr, cmd, 5);
+
+    /*write8(LED0_ON_L+4*num, on);
+    write8(LED0_ON_H+4*num, on >> 8);
+    write8(LED0_OFF_L+4*num, off);
+    write8(LED0_OFF_H+4*num, off >> 8);*/
+}
+
+// Set pwm duty in us order
+void PCA9685Lib::setDuty(uint8_t num, uint16_t duty) {
+    float pulselength = 10000;   // 10,000 us per second
+    duty = 4094 * duty / pulselength;
+    setPWM(num, 0, duty);
+}
+
+uint8_t PCA9685Lib::read8(char addr) {
+    i2c.write(_i2caddr, &addr, 1);
+    char rtn;
+    i2c.read(_i2caddr, &rtn, 1);
+    return rtn;
+}
+
+void PCA9685Lib::write8(char addr, char d) {
+    char cmd[2];
+    cmd[0] = addr;
+    cmd[1] = d;
+    i2c.write(_i2caddr, cmd, 2);
+}
+
+