Adafruit_PWM Arduino Sketch¶
This sketch is used by Exercise: Adafruit PWM I2C Module.
Full Source Code¶
The main code is in Adafruit_PWM.ino.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 | /***************************************************
This is an example for our Adafruit 16-channel PWM & Servo driver
PWM test - this will drive 16 PWMs in a 'wave'
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
****************************************************/
#include <Wire.h>
// #include <Adafruit_PWMServoDriver.h>
#include "Adafruit_PWMServoDriver.h"
// called this way, it uses the default address 0x40
Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver();
// you can also call it with a different address you want
//Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver(0x41);
void setup() {
Serial.begin(9600);
Serial.println("16 channel PWM test!");
// if you want to really speed stuff up, you can go into 'fast 400khz I2C' mode
// some i2c devices dont like this so much so if you're sharing the bus, watch
// out for this!
pwm.begin();
pwm.setPWMFreq(1600); // This is the maximum PWM frequency
// save I2C bitrate
uint8_t twbrbackup = TWBR;
// must be changed after calling Wire.begin() (inside pwm.begin())
TWBR = 12; // upgrade to 400KHz!
}
void loop() {
// Drive each PWM in a 'wave'
for (uint16_t i=0; i<4096; i += 8) {
for (uint8_t pwmnum=0; pwmnum < 16; pwmnum++) {
pwm.setPWM(pwmnum, 0, (i + (4096/16)*pwmnum) % 4096 );
}
}
}
|
The supporting code is in Adafruit_PWM.ino.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 | /***************************************************
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
****************************************************/
// #include <Adafruit_PWMServoDriver.h>
#include "Adafruit_PWMServoDriver.h"
#include <Wire.h>
#if defined(__AVR__)
#define WIRE Wire
#elif defined(CORE_TEENSY) // Teensy boards
#define WIRE Wire
#else // Arduino Due
#define WIRE Wire1
#endif
// Set to true to print some debug messages, or false to disable them.
#define ENABLE_DEBUG_OUTPUT true
Adafruit_PWMServoDriver::Adafruit_PWMServoDriver(uint8_t addr) {
_i2caddr = addr;
}
void Adafruit_PWMServoDriver::begin(void) {
WIRE.begin();
reset();
}
void Adafruit_PWMServoDriver::reset(void) {
write8(PCA9685_MODE1, 0x0);
}
void Adafruit_PWMServoDriver::setPWMFreq(float freq) {
//Serial.print("Attempting to set freq ");
//Serial.println(freq);
freq *= 0.9; // Correct for overshoot in the frequency setting (see issue #11).
float prescaleval = 25000000;
prescaleval /= 4096;
prescaleval /= freq;
prescaleval -= 1;
if (ENABLE_DEBUG_OUTPUT) {
Serial.print("Estimated pre-scale: "); Serial.println(prescaleval);
}
uint8_t prescale = floor(prescaleval + 0.5);
if (ENABLE_DEBUG_OUTPUT) {
Serial.print("Final pre-scale: "); Serial.println(prescale);
}
uint8_t oldmode = read8(PCA9685_MODE1);
uint8_t newmode = (oldmode&0x7F) | 0x10; // sleep
write8(PCA9685_MODE1, newmode); // go to sleep
write8(PCA9685_PRESCALE, prescale); // set the prescaler
write8(PCA9685_MODE1, oldmode);
delay(5);
write8(PCA9685_MODE1, oldmode | 0xa1); // This sets the MODE1 register to turn on auto increment.
// This is why the beginTransmission below was not working.
// Serial.print("Mode now 0x"); Serial.println(read8(PCA9685_MODE1), HEX);
}
void Adafruit_PWMServoDriver::setPWM(uint8_t num, uint16_t on, uint16_t off) {
//Serial.print("Setting PWM "); Serial.print(num); Serial.print(": "); Serial.print(on); Serial.print("->"); Serial.println(off);
WIRE.beginTransmission(_i2caddr);
WIRE.write(LED0_ON_L+4*num);
WIRE.write(on);
WIRE.write(on>>8);
WIRE.write(off);
WIRE.write(off>>8);
WIRE.endTransmission();
}
// Sets pin without having to deal with on/off tick placement and properly handles
// a zero value as completely off. Optional invert parameter supports inverting
// the pulse for sinking to ground. Val should be a value from 0 to 4095 inclusive.
void Adafruit_PWMServoDriver::setPin(uint8_t num, uint16_t val, bool invert)
{
// Clamp value between 0 and 4095 inclusive.
val = min(val, 4095);
if (invert) {
if (val == 0) {
// Special value for signal fully on.
setPWM(num, 4096, 0);
}
else if (val == 4095) {
// Special value for signal fully off.
setPWM(num, 0, 4096);
}
else {
setPWM(num, 0, 4095-val);
}
}
else {
if (val == 4095) {
// Special value for signal fully on.
setPWM(num, 4096, 0);
}
else if (val == 0) {
// Special value for signal fully off.
setPWM(num, 0, 4096);
}
else {
setPWM(num, 0, val);
}
}
}
uint8_t Adafruit_PWMServoDriver::read8(uint8_t addr) {
WIRE.beginTransmission(_i2caddr);
WIRE.write(addr);
WIRE.endTransmission();
WIRE.requestFrom((uint8_t)_i2caddr, (uint8_t)1);
return WIRE.read();
}
void Adafruit_PWMServoDriver::write8(uint8_t addr, uint8_t d) {
WIRE.beginTransmission(_i2caddr);
WIRE.write(addr);
WIRE.write(d);
WIRE.endTransmission();
}
|
The supporting definitions are in Adafruit_PWM.ino.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 | /***************************************************
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
****************************************************/
#ifndef _ADAFRUIT_PWMServoDriver_H
#define _ADAFRUIT_PWMServoDriver_H
#if ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
#define PCA9685_SUBADR1 0x2
#define PCA9685_SUBADR2 0x3
#define PCA9685_SUBADR3 0x4
#define PCA9685_MODE1 0x0
#define PCA9685_PRESCALE 0xFE
#define LED0_ON_L 0x6
#define LED0_ON_H 0x7
#define LED0_OFF_L 0x8
#define LED0_OFF_H 0x9
#define ALLLED_ON_L 0xFA
#define ALLLED_ON_H 0xFB
#define ALLLED_OFF_L 0xFC
#define ALLLED_OFF_H 0xFD
class Adafruit_PWMServoDriver {
public:
Adafruit_PWMServoDriver(uint8_t addr = 0x40);
void begin(void);
void reset(void);
void setPWMFreq(float freq);
void setPWM(uint8_t num, uint16_t on, uint16_t off);
void setPin(uint8_t num, uint16_t val, bool invert=false);
private:
uint8_t _i2caddr;
uint8_t read8(uint8_t addr);
void write8(uint8_t addr, uint8_t d);
};
#endif
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