the pca9685 is not the most precise chip so tweaking with a scope is a great idea

developpment/drivers/pca9685/pca9685.cpp

@@ -7,7 +7,7 @@ Pca9685::Pca9685(i2c_ch1_pImpL* i2c, ErrorHandler* err)
 	errorHandling = err; 
 	m_isExternalClock = 0; 	
 	m_oscillatorFreq = PCA9685_FREQUENCY_OSCILLATOR;
-	setPwmFreq(48); 
+	setPwmFreq(1526); 
 	m_currentLED = PCA9685_LED_PWM_REG_START; 
 
 	errorHandling->addNewError(-1,__FILE__,"Selected duty cycle is too big",KILL);
@@ -31,7 +31,7 @@ Pca9685::Pca9685(i2c_ch1_pImpL* i2c, ErrorHandler* err)
  *
  */
 
-void Pca9685::setPwmFreq(uint16_t frequency)
+void Pca9685::setPwmFreq(float frequency)
 {
 	if(frequency > 1526)
 	{
@@ -49,17 +49,21 @@ void Pca9685::setPwmFreq(uint16_t frequency)
 		errorHandling->handleError(-4,__FILE__); 
 	}
 
-	m_currentPrescale = (m_oscillatorFreq / ( 4096 * frequency) ) -1;
-	std::cout << "Prescaler is set to: " << unsigned(m_currentPrescale) << std::endl; 	
+	m_currentPrescale = round((m_oscillatorFreq / ( 4096 * frequency)) - 1);
+	std::cout << unsigned(m_currentPrescale) << std::endl;
 	sleep(); 
 	i2c_pca9685->writeWord(PCA9685_I2C_ADDRESS, PCA9685_REG_PRESCALE, m_currentPrescale);
 	wakeup(); 
 }
 
-void Pca9685::setPwmMicroSeconds(uint16_t microSeconds)
+float Pca9685::getPwmFreq()
 {
-	
+	m_currentPrescale = i2c_pca9685->readByte(PCA9685_I2C_ADDRESS,PCA9685_REG_PRESCALE); 
+	m_currentPwmFreq = (m_oscillatorFreq / (4096 * ((float)m_currentPrescale + 1)));
+	std::cout << m_currentPwmFreq << std::endl;
+	return m_currentPwmFreq;
 }
+
 void Pca9685::setDutyPercent(uint8_t ledNo, uint8_t on, uint8_t off)
 {
 	
@@ -102,10 +106,6 @@ void Pca9685::setDutyRaw(uint8_t ledNo, uint16_t on, uint16_t off)
 	i2c_pca9685->writeWord(PCA9685_I2C_ADDRESS, m_currentLED + PCA9685_PWM_OFF_H_OFFSET, off >> 8);
 }
 
-void Pca9685::setDutyMicroSecond(uint8_t ledNo, uint16_t on, uint16_t off)
-{
-}
-
 void Pca9685::setOnOff(uint8_t ledNo, bool onOff, bool invert)
 {
 	
@@ -161,3 +161,4 @@ void Pca9685::wakeup()
 	i2c_pca9685->writeWord(PCA9685_I2C_ADDRESS, PCA9685_REG_MODE1, m_curMode);
 	usleep(PCA9685_OSC_STAB_TIME_US); // refer to datasheet page 14
 }
+

developpment/drivers/pca9685/pca9685.h

@@ -57,8 +57,8 @@ class Pca9685
 {
 	public:
 		Pca9685(i2c_ch1_pImpL* i2c,ErrorHandler* err);
-		void setPwmFreq(uint16_t frequency);
-		void setPwmMicroSeconds(uint16_t microSeconds);
+		void setPwmFreq(float frequency);
+		float getPwmFreq(); 
 		void setDutyPercent(uint8_t ledNo, uint8_t on, uint8_t off);
 		void setDutyRaw(uint8_t ledNo, uint16_t on, uint16_t off);
 		void setDutyMicroSecond(uint8_t ledNo, uint16_t on, uint16_t off);
@@ -71,10 +71,10 @@ class Pca9685
 	private:
 		uint8_t	m_currentLED; 
 		uint8_t m_curMode;
-		uint16_t m_currentPwmFreq; 
+		float m_currentPwmFreq; 
 		uint8_t m_currentPrescale;
 		uint8_t m_isExternalClock; 
-		uint32_t m_oscillatorFreq; 
+		float m_oscillatorFreq; 
 		ErrorHandler* errorHandling;
 		i2c_ch1_pImpL* i2c_pca9685;
 };

developpment/interfacer.cpp

@@ -25,10 +25,15 @@ Pca9685 pwmGenarator(&i2c, &errorHandle);
 
 int initPlatform()
 {
-	char Msg[6] = "hello"; 
+	char char_array[TOTAL_CHAR_CAP];
+	uint8_t pos = 0; 
 	lcd_init(&i2c); 
-	lcd_display_string(1,0,Msg); 
-	// Dev. Module initialisation "Ex i2c_init() ...."
+	strcpy(char_array, "Pwm Freq: ");
+	lcd_display_string(1,pos,char_array); 
+	std::string Msg = std::to_string(pwmGenarator.getPwmFreq()); 
+	strcpy(char_array, Msg.c_str());
+	pos = strlen(char_array) + 1; 
+	lcd_display_string(1,pos, char_array); 
 	return 0; 
 }