release lib v1.2

Author: MartinStokroos

README.md

@@ -1,17 +1,19 @@
-# Native DDS Library for Arduino
-This repository contains the *NativeDDS* library for Arduino. *NativeDDS* is a software implemented Direct Digital Synthesizer. *NativeDDS* generates sinusoidal waves for example for use in audio applications, motor drives, sine wave inverters or as a reference frequency source. The library is easy portable to other platforms.
+# Native DDS Library for Arduino v1.2
+This repository contains the *NativeDDS* library for Arduino. *NativeDDS* is a software implemented Direct Digital Synthesizer. *NativeDDS* generates sinusoidal waves for example for use in audio applications, motor drives, sine wave inverters or for a reference frequency source. The library is easy portable to other platforms.
 
 ## Function
-The DDS frequency resolution is 32-bit. This means that the frequency can be tuned with steps of `f_update/(2^32)`, with `f_update = 1/timestep` (see below). The amplitude resolution can be set to eight bit or ten bit by defining `EIGHTBIT` or `TENBIT` in the `NativeDDS.h` file. The eight bit implementation is faster and will be precise enough for most applications.
+The DDS frequency resolution is 32-bit. This means that the frequency can be tuned in steps of `f_update/(2^32)`, with `f_update = 1/timestep` (see below). The amplitude resolution can be eight bits or ten bits by choosing the class instances `DDS_8bit_xx` or `DDS_10bit_xx`. The eight bit implementation is faster and will be precise enough in most applications.
 
-The following library classes are implemented:
+The following library instance methods are implemented:
 
-* `DDS_1Ch`
-* `DDS_2Ch`
-* `DDS_IQ`
-* `DDS_3Ph`
+* `DDS_8bit_1Ch or DDS_10bit_1Ch`
+* `DDS_8bit_2Ch or DDS_10bit_2Ch`
+* `DDS_8bit_IQ or DDS_10bit_IQ`
+* `DDS_8bit_3Ph or DDS_10bit_3Ph`
 
-`DDS_1Ch` is a single (output) channel DDS, `DDS_2Ch` is a dual channel DDS, `DDS_IQ` is a dual channel DDS with orthogonal outputs and `DDS_3Ph` is a three channel DDS.
+The explanation below will be continued for the 8-bit case.
+
+`DDS_8bit_1Ch` is a single (output) channel DDS, `DDS_8bit_2Ch` is a dual channel DDS, `DDS_8bit_IQ` is a dual channel DDS generating orthogonal outputs and `DDS_8bit_3Ph` is a three output channel DDS.
 
 The following methods exists:
 
@@ -21,31 +23,31 @@ The following methods exists:
 
 Initialize the class instance with the member function `begin()`. Also, `begin()` must be called each time when the frequency or phase has to be updated.
 
-DDS_1Ch,  use: `.begin(float frequency, float starting-phase, float timestep);`
+DDS_8bit_1Ch,  use: `.begin(float frequency, float starting-phase, float timestep);`
 
-DDS_2Ch,  use: `.begin(float frequency1, float frequency2, starting-phase1, float starting-phase2, timestep);`
+DDS_8bit_2Ch,  use: `.begin(float frequency1, float frequency2, starting-phase1, float starting-phase2, timestep);`
 
-DDS_IQ, use: `.begin(float frequency, float starting-phase, float timestep);`
+DDS_8bit_IQ, use: `.begin(float frequency, float starting-phase, float timestep);`
 
-DDS_3Ph, use: `.begin(float frequency, float starting-phase, float timestep);`
+DDS_8bit_3Ph, use: `.begin(float frequency, float starting-phase, float timestep);`
 
-For the member function `.begin()`, the variable `frequency` is in Hz and `starting-phase` in radians. `timestep` is the loop iteration time period in seconds with which `.update()` is repeatedly invoked.
+For the member function `.begin()`, the variable `frequency` is in Hz and `starting-phase` in radians. `timestep` is the loop repeating time in seconds at which `.update()` is invoked.
 
-The following public variables are defined for the outputs:
+The following public output variables are defined:
 
-DDS_1Ch: `out1`
+DDS_8bit_1Ch: `out1` and `uout1` for unsigned.
 
-DDS_2Ch: `out1`, `out2`
+DDS_8bit_2Ch: `out1`, `out2` and `uout1`, `uout2` for unsigned. 
 
-DDS_IQ: `outi`, `outq`
+DDS_8bit_IQ: `outi`, `outq` and `uouti`, `uoutq` for unsigned.
 
-DDS_3Ph: `outu`, `outv`, `outw`
+DDS_8bit_3Ph: `outu`, `outv`, `outw` and `uoutu`, `uoutv`, `uoutw` for unsigned.
 
 ## Usage
 * First create an instance of the library object, for example here we define *mySin*:
 
 ```
-DDS_1Ch mySine;
+DDS_8bit_1Ch mySine;
 ```
 
 * Initialize the DDS on some place in your setup function: 
@@ -60,24 +62,26 @@ void setup() {
 
 * Call `mySine.update();` from the main loop or from an Interrupt Service Routine (ISR). Use `.update(void)` on the basis of a regular time interval to generate a jitter free output signal.
 
-Right after the previous step, the instantaneous output value is obtained with: `int sample = mySine.out1;`
+Right after the previous step, the instantaneous (unsigned) output value is obtained with: `int sample = mySine.uout1;`
 
 ```
 void loop() {
 	...
 	mySine.update();
-	sample=mySine.out1
-	analogWrite(PWM_OUT, sample + 127); // add 127 to convert to unsigned.
+	sample=mySine.uout1
+	analogWrite(PWM_OUT, sample);
 	...
 }
 ```
 
 ## Examples
-`SineWave.ino` - Example of a single channel DDS. The time base is generated in the main loop. The maximum usable output frequency is limited to about 100Hz.
+`SineWave_8bit.ino` - Example of a single channel 8-bits DDS. The time base is generated in the main loop. The maximum usable output frequency is limited to about 100Hz.
+
+`SineWave_10bit.ino` - Example of a single channel 10-bits DDS. The time base is generated in the main loop. The maximum usable output frequency is limited to about 100Hz.
 
 `WobblingServo.ino` - A slowly sine-wave modulated servo motor application.
 
-`AudioGenerator.ino` - A generator for audible frequencies. A timer interrupt has been used to create a fixed time base.
+`AudioGenerator.ino` - A generator for audible frequencies. A timer interrupt has been used to create the time base.
 
 ## Acknowledgement
 A lot of time was saved in developing this library by using the alternative Arduino-IDE [Sloeber](https://eclipse.baeyens.it/). Sloeber is a wonderful Arduino plugin for Eclipse. Thanks to Jantje and his contributors!

examples/AudioGenerator/AudioGenerator.ino

@@ -2,9 +2,9 @@
  *
  * File: AudioGenerator.ino
  * Purpose: Native Direct Digital Synthesizer library example project
- * Version: 1.0.2
+ * Version: 1.0.3
  * Release date: 24-10-2018
- * Last edit date: 10-08-2020
+ * Last edit date: 02-11-2020
  * 
  * URL: https://github.com/MartinStokroos/NativeDDS
  * License: MIT License
@@ -13,6 +13,7 @@
  * v1.0.0, 24 Oct 2018 - initial release
  * v1.0.1, 18 Nov 2018 - textual changes in comments
  * v1.0.2, 10-08-2020 - select 8-bit/10bit DDS from main c file but it does not work (yet).
+ * v1.0.3, 02-11-2020 - library update for seperate instance methods for 8-bit and 10-bit DDS
  * 
  * This sketch demonstrates the Native DDS library. Native DDS is a Direct Digital Synthesizer
  * algorithm that runs in software on the Arduino. In this example, a 220Hz and a 440Hz sine wave are 
@@ -31,7 +32,6 @@
  *
 */
 
-//#define DDS_8BIT  //Why does defining it here won't work? Now it still should be done from NativeDDS.h
 #include "NativeDDS.h"
 
 //#define DEBUG
@@ -50,7 +50,7 @@
 const float Ts = 3.1875E-5; // Timer2 period
 float f = 220.0; // Wanted DDS output frequency
 
-DDS_2Ch mySine;	// Create instance of DDS_2Ch for a dual channel DDS.
+DDS_8bit_2Ch mySine;	// Create instance of DDS_8bit_2Ch for a dual channel DDS.
 
 
 
@@ -97,13 +97,12 @@ ISR(TIMER2_OVF_vect) {
 	#endif
 
 	mySine.update();
-	OCR2B = mySine.out1 + 127;  // output PWM_OUT1 directly updated with the OCR2B register value (220Hz)
-	OCR2A = mySine.out2 + 127;  // output PWM_OUT2 directly updated with the OCR2A register value (440Hz)
+	OCR2B = mySine.uout1;  // PWM_OUT1 directly updated by writing the OCR2B register value (220Hz)
+	OCR2A = mySine.uout2;  // PWM_OUT2 directly updated by writing the OCR2A register value (440Hz)
 
 	#if defined(DEBUG)
 		digitalWriteFast(DEBUG_PIN, false);
 	#endif
 }
 
 // end of AudioGenerator.ino
-

examples/SineWave/SineWave.ino …amples/SineWave_10bit/SineWave_10bit.inoexamples/SineWave/SineWave.ino renamed to examples/SineWave_10bit/SineWave_10bit.ino examples/SineWave/SineWave.ino renamed to examples/SineWave_10bit/SineWave_10bit.ino

@@ -1,17 +1,16 @@
 /*
- * File: SineWave.ino
+ * File: SineWave_10bit.ino
  * Purpose: Native Direct Digital Synthesizer library example project
- * Version: 1.1.1
+ * Version: 1.0.0
  * First release date: 22-10-2018
- * Last edit date: 10-08-2020
+ * Last edit date:
  * 
  * URL: https://github.com/MartinStokroos/NativeDDS
  * License: MIT License
  *
  * Version history:
- * v1.0.0, 22 Oct 2018 - initial release
- * v1.1.0, 18 Nov 2018 - looptime=200us (5kHz). Pin3 + pin11 PWM frequency=31250Hz and the output frequency=100Hz.
- * v1.1.1, 10-08-2020 - select 8-bit/10bit DDS from main c file but it does not work (yet).
+ * 
+ * v1.0.0, 02-11-2020 - separate instance methods for 8-bit / 10-bit DDS.
  * 
  * This sketch demonstrates the Native DDS library. Native DDS is a Direct Digital Synthesizer
  * algorithm that runs in software on the Arduino. In this example the output frequency is set to 100Hz.
@@ -32,28 +31,28 @@
  *
 */
 
-//#define DDS_8BIT  //Why does defining it here won't work? Now it still should be done from NativeDDS.h
 #include "NativeDDS.h"
 
 #define LPERIOD 200     // loop period time in us. Update freq. is 5kHz
+
 #define PWM_OUT 3       // define PWM output pin
 #define DEBUG_PIN 13    // define debug PIN for timing observation (=LED pin)
 
 double frequency = 100.0; // output frequency in Hz
 unsigned long nextLoop;
 int output;
 
-DDS_1Ch mySine; // create instance of DDS_1Ch
+DDS_10bit_1Ch mySine; // create instance of DDS_10bit_1Ch
 
 
 
 void setup() {
 	// run once:
 	pinMode(PWM_OUT, OUTPUT);
 	pinMode(DEBUG_PIN, OUTPUT);
-  TCCR2B = (TCCR2B & 0xF8)|0x01;    // set Pin3 + Pin11 PWM frequency to 31250Hz
+  TCCR2B = (TCCR2B & 0xF8)|0x01;    // Set Pin3 + Pin11 PWM frequency to 31250Hz.
 
-	mySine.begin(frequency, 0, LPERIOD*1.0e-6); // initilize the DDS (frequency, startphase, update period time)
+	mySine.begin(frequency, 0, LPERIOD*1.0e-6); // Initilize the DDS (frequency, startphase, update period time).
 
 	nextLoop = micros() + LPERIOD; // Set the loop timer variable for the next loop interval.
 	}
@@ -63,27 +62,16 @@ void setup() {
 void loop() {
 	// run repeatedly:
 
-	#ifdef DDS_8BIT
-		//digitalWrite(DEBUG_PIN, HIGH);  // for checking loop period time and loop execution time (signal high time)
-		
-		mySine.update();  //update the DDS, measured execution time <10us
-	
-		//digitalWrite(DEBUG_PIN, LOW);
-		analogWrite(PWM_OUT, mySine.out1 + 127); // add 127 to convert to unsigned.
-   
-	#elif defined (DDS_10BIT)
-		//digitalWrite(DEBUG_PIN, HIGH);  // debugging: check loop period time and loop execution time (signal high time)
-		
-		mySine.update();  // update the DDS, measured execution time <20us
-		
-		//digitalWrite(DEBUG_PIN, LOW);
-		output = mySine.out1 + 511; // add 511 to convert to unsigned.
-		analogWrite(PWM_OUT, output>>2); // convert back to to 8-bit and write to analog out.
-	#endif
+	//digitalWrite(DEBUG_PIN, HIGH);  // debugging: for checking loop cycling time and function execution time (signal high time)
+	mySine.update();  // update the DDS, measured execution time <20us
+	//digitalWrite(DEBUG_PIN, LOW);
+ 
+	//output = mySine.out1 + 511; // add 511 to convert to unsigned.
+  output = mySine.uout1; // use unsigned output.
+	analogWrite(PWM_OUT, output>>2); // convert back to 8-bit and write to analog out.
 
 	while(nextLoop > micros());  // wait until the end of the time interval
-	nextLoop += LPERIOD;  // set next loop time at current time + LOOP_PERIOD
+  nextLoop += LPERIOD;  // set next loop time at current time + LOOP_PERIOD
 	}
 
-// end of SineWave.ino
-
+// end of SineWave_10bit.ino

examples/SineWave_8bit/SineWave_8bit.ino

@@ -0,0 +1,75 @@
+/*
+ * File: SineWave_8bit.ino
+ * Purpose: Native Direct Digital Synthesizer library example project
+ * Version: 1.0.0
+ * First release date: 02-11-2020
+ * Last edit date:
+ * 
+ * URL: https://github.com/MartinStokroos/NativeDDS
+ * License: MIT License
+ * Version history:
+ * 
+ * v1.0.0, 02-11-2020 - separate instance methods for 8-bit / 10-bit DDS.
+ * 
+ * This sketch demonstrates the Native DDS library. Native DDS is a Direct Digital Synthesizer
+ * algorithm that runs in software on the Arduino. In this example the output frequency is set to 100Hz.
+ * The pulse width modulated sine wave is available on pin 3.
+ *
+ * In this example the DDS runs at 5kHz (the update frequency of the DDS). In theory the maximum output frequency 
+ * at 5kHz update rate is 2500Hz. To get a smooth output wave, a low pass filter (RC or multistage LC), is required.
+ * For more information please read: A Technical Tutorial on Digital Signal Synthesis, Ken Gentile and Rick Cushing, 
+ * Analog Devices, 1999.
+ *
+ * NOTE: The DDS output is sent to the PWM output pin with the analogWrite function. analogWrite sets the duty-cycle
+ * of the PWM signal corresponding to the wanted average output voltage level. The default PWM-frequency of pin 3
+ * is approximately 490Hz. Because of this low PWM frequency, the maximum usable DDS output frequency is even lower.
+ * For this reason the pwm frequency has been set to much a higher frequency than the DDS update frequency in this example.
+ *
+ * The loop timing can be observed with an oscilloscope on pin 13 (uncomment the lines with a digitalWrite).
+ * Please, also check the other example projects of the NativeDDS library.
+ *
+*/
+
+#include "NativeDDS.h"
+
+#define LPERIOD 200     // loop period time in us. Update freq. is 5kHz
+
+#define PWM_OUT 3       // define PWM output pin
+#define DEBUG_PIN 13    // define debug PIN for timing observation (=LED pin)
+
+double frequency = 100.0; // output frequency in Hz
+unsigned long nextLoop;
+int output;
+
+DDS_8bit_1Ch mySine; // create instance of DDS_1Ch
+
+
+
+void setup() {
+	// run once:
+	pinMode(PWM_OUT, OUTPUT);
+	pinMode(DEBUG_PIN, OUTPUT);
+  TCCR2B = (TCCR2B & 0xF8)|0x01;    // Set Pin3 + Pin11 PWM frequency to 31250Hz.
+
+	mySine.begin(frequency, 0, LPERIOD*1.0e-6); // Initilize the DDS (frequency, startphase, update period time).
+
+	nextLoop = micros() + LPERIOD; // Set the loop timer variable for the next loop interval.
+	}
+
+
+
+void loop() {
+	// run repeatedly:
+  
+	//digitalWrite(DEBUG_PIN, HIGH);  // for checking loop cycling time and function execution time (signal high time)
+  mySine.update();  // update DDS. Measured execution time <10us.
+	//digitalWrite(DEBUG_PIN, LOW);
+
+	//analogWrite(PWM_OUT, mySine.out1 + 127); // add 127 to convert to unsigned.
+  analogWrite(PWM_OUT, mySine.uout1); // use unsigned output.
+
+	while(nextLoop > micros());  // wait until the end of the time interval
+  nextLoop += LPERIOD;  // set next loop time at current time + LOOP_PERIOD
+	}
+
+// end of SineWave_8bit.ino