2020年09月07日 | PCA9685 PWM舵机驱动板16路模块 IIC接口

16路模块 PWM舵机驱动板 控制器 机器人 IIC接口 使用说明书

AdafruitPWMServoDriverLibrary单片机源程序如下:

/***************************************************

  This is a library for our Adafruit 16-channel PWM & Servo driver

  Pick one up today in the adafruit shop!

  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

#include

#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();

}