Merge branch 'photodude-patch-1'

Author: ladyada

.travis.yml

@@ -1,19 +1,31 @@
 language: c
 sudo: false
-
-# Blacklist
-branches:
-  except:
-    - gh-pages
+cache:
+  directories:
+    - ~/arduino_ide
+    - ~/.arduino15/packages/
+git:
+  depth: false
+  quiet: true
 
 env:
   global:
      - PRETTYNAME="Adafruit PCA9685 PWM Servo Driver Arduino Library"
 
+addons:
+  apt:
+    sources:
+      - llvm-toolchain-trusty-5.0
+      - key_url: 'http://apt.llvm.org/llvm-snapshot.gpg.key'
+    packages:
+      - clang-format-5.0
+
 before_install:
    - source <(curl -SLs https://raw.githubusercontent.com/adafruit/travis-ci-arduino/master/install.sh)
+   - curl -SLs https://raw.githubusercontent.com/adafruit/travis-ci-arduino/master/run-clang-format.py > run-clang-format.py
 
 script:
+   - python run-clang-format.py -r .
    - build_main_platforms
 
 # Generate and deploy documentation

Adafruit_PWMServoDriver.cpp

@@ -30,22 +30,22 @@
 #include "Adafruit_PWMServoDriver.h"
 #include <Wire.h>
 
+//#define ENABLE_DEBUG_OUTPUT
+
 /*!
  *  @brief  Instantiates a new PCA9685 PWM driver chip with the I2C address on a
  * TwoWire interface
  */
-Adafruit_PWMServoDriver::Adafruit_PWMServoDriver():
-  _i2caddr(PCA9685_I2C_ADDRESS), _i2c(&Wire) {
-}
+Adafruit_PWMServoDriver::Adafruit_PWMServoDriver()
+    : _i2caddr(PCA9685_I2C_ADDRESS), _i2c(&Wire) {}
 
 /*!
  *  @brief  Instantiates a new PCA9685 PWM driver chip with the I2C address on a
  * TwoWire interface
  *  @param  addr The 7-bit I2C address to locate this chip, default is 0x40
  */
-Adafruit_PWMServoDriver::Adafruit_PWMServoDriver(const uint8_t addr):
-  _i2caddr(addr), _i2c(&Wire) {
-}
+Adafruit_PWMServoDriver::Adafruit_PWMServoDriver(const uint8_t addr)
+    : _i2caddr(addr), _i2c(&Wire) {}
 
 /*!
  *  @brief  Instantiates a new PCA9685 PWM driver chip with the I2C address on a
@@ -54,9 +54,9 @@ Adafruit_PWMServoDriver::Adafruit_PWMServoDriver(const uint8_t addr):
  *  @param  i2c  A reference to a 'TwoWire' object that we'll use to communicate
  *  with
  */
-Adafruit_PWMServoDriver::Adafruit_PWMServoDriver(const uint8_t addr, TwoWire& i2c) :
-  _i2caddr(addr), _i2c(&i2c) {
-}
+Adafruit_PWMServoDriver::Adafruit_PWMServoDriver(const uint8_t addr,
+                                                 TwoWire &i2c)
+    : _i2caddr(addr), _i2c(&i2c) {}
 
 /*!
  *  @brief  Setups the I2C interface and hardware
@@ -72,6 +72,8 @@ void Adafruit_PWMServoDriver::begin(uint8_t prescale) {
     // set a default frequency
     setPWMFreq(1000);
   }
+  // set the default internal frequency
+  setOscillatorFrequency(FREQUENCY_OSCILLATOR);
 }
 
 /*!
@@ -137,21 +139,17 @@ void Adafruit_PWMServoDriver::setPWMFreq(float freq) {
   Serial.println(freq);
 #endif
   // Range output modulation frequency is dependant on oscillator
-  if (freq < 1) freq = 1;
-  if (freq > 3500) freq = 3500; // Datasheet limit is 3052=50MHz/(4*4096)
-  /*
-  freq *= 0.9; // Correct for overshoot in the frequency setting (see issue #11)
-  float prescaleval = FREQUENCY_OSCILLATOR;
-  */
-  uint32_t prescaleval = FREQUENCY_CALIBRATED;
-  prescaleval /= freq; // required output modulation frequency
-  // rounding to nearest number is equal to adding 0,5 and floor to nearest number
-  prescaleval += 2048;
-  prescaleval /= 4096;
-  prescaleval -= 1;
-  if (prescaleval < PCA9685_PRESCALE_MIN) prescaleval = PCA9685_PRESCALE_MIN;
-  if (prescaleval > PCA9685_PRESCALE_MAX) prescaleval = PCA9685_PRESCALE_MAX;
-  uint8_t prescale = (uint8_t) prescaleval;
+  if (freq < 1)
+    freq = 1;
+  if (freq > 3500)
+    freq = 3500; // Datasheet limit is 3052=50MHz/(4*4096)
+
+  float prescaleval = ((_oscillator_freq / (freq * 4096.0)) + 0.5) - 1;
+  if (prescaleval < PCA9685_PRESCALE_MIN)
+    prescaleval = PCA9685_PRESCALE_MIN;
+  if (prescaleval > PCA9685_PRESCALE_MAX)
+    prescaleval = PCA9685_PRESCALE_MAX;
+  uint8_t prescale = (uint8_t)prescaleval;
 
 #ifdef ENABLE_DEBUG_OUTPUT
   Serial.print("Final pre-scale: ");
@@ -160,12 +158,12 @@ void Adafruit_PWMServoDriver::setPWMFreq(float freq) {
 
   uint8_t oldmode = read8(PCA9685_MODE1);
   uint8_t newmode = (oldmode & ~MODE1_RESTART) | MODE1_SLEEP; // sleep
-  write8(PCA9685_MODE1, newmode);            // go to sleep
-  write8(PCA9685_PRESCALE, prescale);        // set the prescaler
+  write8(PCA9685_MODE1, newmode);                             // go to sleep
+  write8(PCA9685_PRESCALE, prescale); // set the prescaler
   write8(PCA9685_MODE1, oldmode);
   delay(5);
   // This sets the MODE1 register to turn on auto increment.
-  write8(PCA9685_MODE1, oldmode | MODE1_RESTART | MODE1_AI); 
+  write8(PCA9685_MODE1, oldmode | MODE1_RESTART | MODE1_AI);
 
 #ifdef ENABLE_DEBUG_OUTPUT
   Serial.print("Mode now 0x");
@@ -174,22 +172,21 @@ void Adafruit_PWMServoDriver::setPWMFreq(float freq) {
 }
 
 /*!
- *  @brief  Sets the output mode of the PCA9685 to either 
- *  open drain or push pull / totempole. 
+ *  @brief  Sets the output mode of the PCA9685 to either
+ *  open drain or push pull / totempole.
  *  Warning: LEDs with integrated zener diodes should
- *  only be driven in open drain mode. 
- *  @param  totempole Totempole if true, open drain if false. 
+ *  only be driven in open drain mode.
+ *  @param  totempole Totempole if true, open drain if false.
  */
-void Adafruit_PWMServoDriver::setOutputMode(bool totempole) {  
-  uint8_t oldmode = read8(PCA9685_MODE2); 
+void Adafruit_PWMServoDriver::setOutputMode(bool totempole) {
+  uint8_t oldmode = read8(PCA9685_MODE2);
   uint8_t newmode;
   if (totempole) {
     newmode = oldmode | MODE2_OUTDRV;
-  }
-  else {
+  } else {
     newmode = oldmode & ~MODE2_OUTDRV;
   }
-  write8(PCA9685_MODE2, newmode); 
+  write8(PCA9685_MODE2, newmode);
 #ifdef ENABLE_DEBUG_OUTPUT
   Serial.print("Setting output mode: ");
   Serial.print(totempole ? "totempole" : "open drain");
@@ -202,8 +199,7 @@ void Adafruit_PWMServoDriver::setOutputMode(bool totempole) {
  *  @brief  Reads set Prescale from PCA9685
  *  @return prescale value
  */
-uint8_t Adafruit_PWMServoDriver::readPrescale(void)
-{
+uint8_t Adafruit_PWMServoDriver::readPrescale(void) {
   return read8(PCA9685_PRESCALE);
 }
 
@@ -279,55 +275,74 @@ void Adafruit_PWMServoDriver::setPin(uint8_t num, uint16_t val, bool invert) {
 }
 
 /*!
- *  @brief  Sets the PWM output of one of the PCA9685 pins based on the input microseconds, output is not precise
+ *  @brief  Sets the PWM output of one of the PCA9685 pins based on the input
+ * microseconds, output is not precise
  *  @param  num One of the PWM output pins, from 0 to 15
  *  @param  Microseconds The number of Microseconds to turn the PWM output ON
  */
-void Adafruit_PWMServoDriver::writeMicroseconds(uint8_t num, uint16_t Microseconds) {
-  #ifdef ENABLE_DEBUG_OUTPUT
+void Adafruit_PWMServoDriver::writeMicroseconds(uint8_t num,
+                                                uint16_t Microseconds) {
+#ifdef ENABLE_DEBUG_OUTPUT
   Serial.print("Setting PWM Via Microseconds on output");
   Serial.print(num);
   Serial.print(": ");
   Serial.print(Microseconds);
   Serial.println("->");
-  #endif
+#endif
 
   double pulse = Microseconds;
   double pulselength;
-  pulselength = 1000000;   // 1,000,000 us per second
+  pulselength = 1000000; // 1,000,000 us per second
+
+  // Read prescale
+  uint16_t prescale = Adafruit_PWMServoDriver::readPrescale();
+
+#ifdef ENABLE_DEBUG_OUTPUT
+  Serial.print(prescale);
+  Serial.println(" PCA9685 chip prescale");
+#endif
 
-  // Read prescale and convert to frequency
-  double prescale = Adafruit_PWMServoDriver::readPrescale();
+  // Calculate the pulse for PWM based on Equation 1 from the datasheet section
+  // 7.3.5
   prescale += 1;
-  uint32_t freq = 25000000; // Chip frequency is 25MHz
-  freq /= prescale;
-  freq /= 4096; // 12 bits of resolution
- 
-  #ifdef ENABLE_DEBUG_OUTPUT
-  Serial.print(freq); Serial.println(" Calculated PCA9685 chip PWM Frequency");
-  #endif
-  
-  pulselength /= freq;   //  us per period from PCA9685 chip PWM Frequency using prescale reverse frequency calc
-
-  #ifdef ENABLE_DEBUG_OUTPUT
-  Serial.print(pulselength); Serial.println(" us per period");
-  #endif
-
-  pulselength /= 4096;  // 12 bits of resolution
-
-  #ifdef ENABLE_DEBUG_OUTPUT
-  Serial.print(pulselength); Serial.println(" us per bit"); 
-  #endif
+  pulselength *= prescale;
+  pulselength /= _oscillator_freq;
+
+#ifdef ENABLE_DEBUG_OUTPUT
+  Serial.print(pulselength);
+  Serial.println(" us per bit");
+#endif
 
   pulse /= pulselength;
 
-  #ifdef ENABLE_DEBUG_OUTPUT
-  Serial.print(pulse);Serial.println(" pulse for PWM"); 
-  #endif
+#ifdef ENABLE_DEBUG_OUTPUT
+  Serial.print(pulse);
+  Serial.println(" pulse for PWM");
+#endif
 
   Adafruit_PWMServoDriver::setPWM(num, 0, pulse);
 }
 
+/*!
+ *  @brief  Getter for the internally tracked oscillator used for freq
+ * calculations
+ *  @returns The frequency the PCA9685 thinks it is running at (it cannot
+ * introspect)
+ */
+uint32_t Adafruit_PWMServoDriver::getOscillatorFrequency(void) {
+  return _oscillator_freq;
+}
+
+/*!
+ *  @brief Setter for the internally tracked oscillator used for freq
+ * calculations
+ *  @param freq The frequency the PCA9685 should use for frequency calculations
+ */
+void Adafruit_PWMServoDriver::setOscillatorFrequency(uint32_t freq) {
+  _oscillator_freq = freq;
+}
+
+/******************* Low level I2C interface */
 uint8_t Adafruit_PWMServoDriver::read8(uint8_t addr) {
   _i2c->beginTransmission(_i2caddr);
   _i2c->write(addr);