add trapezium()

Author: RobTillaart

CHANGELOG.md

@@ -9,6 +9,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ## [0.2.7] - 2024-07-05
 - add **float sinusDiode(float t)**
 - add **float sinusRectified(float t)**
+- add **float trapezium1(float t)** with duty cycle.
+- add **float trapezium2(float t)** with duty cycle.
+- update **functionGeneratorPerformance.ino**
+- fix Arduino-lint.yml (long library name error)
 - minor edits
 
 ## [0.2.6] - 2023-11-02

README.md

@@ -72,6 +72,8 @@ have become slightly slower.
 |  Arduino UNO  |  16 MHz   |  square    |   57        |  1000 Hz   |
 |  Arduino UNO  |  16 MHz   |  random_DC |   68        |   500 Hz   |
 
+See **functionGeneratorPerformance.ino**
+
 
 #### Accuracy
 
@@ -130,10 +132,6 @@ The variable t == time in seconds.
 - **float triangle(float t)** triangle form, duty cycle default 50%. 
 - **float square(float t)** square wave with duty cycle default 50%.
 - **float sinus(float t)** sinus wave, has no duty cycle.
-- **float sinusDiode(float t)** sinus wave, only positive pulses.
-(Better name welcome).
-- **float sinusRectified(float t)** sinus wave, with "abs(negative pulses)".
-(Better name welcome).
 - **float stair(float t, uint16_t steps = 8, uint8_t mode = 0)** defaults to 8 steps up.
   - mode = 0 ==> steps up
   - mode = 1 ==> steps down. Effectively equals inverting the amplitude.
@@ -146,6 +144,17 @@ The functions **line()** and **zero()** can be used to drive a constant voltage
 from a DAC and can be used to calibrate the generator / DAC combination.
 
 
+Experimental 0.2.7
+
+- **float sinusDiode(float t)** sinus wave, only positive pulses.  
+(better name welcome).
+- **float sinusRectified(float t)** sinus wave, with "abs(negative pulses)".  
+(better name welcome).
+- **float trapezium1(float t)** trapezium wave, DutyCycle changes steepness falling rising.
+- **float trapezium2(float t)** trapezium wave, DutyCycle changes period HIGH vs LOW
+
+Note at 50% DC the two trapezium functions are identical.
+
 #### Duty Cycle 
 
 Since 0.2.5 the library has **experimental** support for duty cycle.
@@ -164,7 +173,14 @@ with respect to previous value.
 Implemented as a weighed average between new and previous value.
 Made a separate function as handling the duty cycle slows performance substantial.
 Initial starts at zero and can be adjusted with **YShift()**.
+- **float trapezium1(float t)** The duty cycle determines the steepness of the rising
+and falling edges. This changes the form from square wave to trapezium to triangle.
+The length of the HIGH LOW level go from 0 to half a period.
+- **float trapezium2(float t)** The duty cycle determines the length of the HIGH level,
+which is 0 for 0% DC and half a period for 100% DC. 
+The rising and falling edges stay same.
 
+#### No duty cycle
 
 The other functions need to be investigated what duty cycle means.
 Current ideas that are **NOT** implemented:
@@ -175,32 +191,33 @@ Think of it as the halve of the triangle wave.
 - **stair()** like sawtooth??
 - **line()** has no period so does not make sense (yet).
 - **zero()** has no period so does not make sense (yet).
+- **float sinusDiode(float t)**
+- **float sinusRectified(float t)**
+
 
 Feedback and ideas are welcome.
 
 
 ## Future
 
-
 #### Must
 
 - documentation
   - quality of signals - after substantial time t
   - max freq per wave form etc.
     Should this be in the library?
 
-
 #### Should
 
 - smart reseed needed for random().
 - initialize random generator with compile time.
 
-
 #### Could
 
 - waves
-  - trapezium wave (could merge square and triangle and sawtooth)
   - white noise, pink noise etc.
+  - heart beat (quite complex but fun)
+  - multiMap interpolation point curves.
 - RC function curve.
 - external clock to synchronize two or more software function generators.
 - stand-alone functions in separate .h
@@ -211,7 +228,6 @@ Feedback and ideas are welcome.
   - add float variable for ```_perDC = _period * _dutyCycle```
   - do we need **freq4** ? not since DC.
 
-
 #### Examples
 
   - Amplitude modulation ?

examples/functionGeneratorPerformance/functionGeneratorPerformance.ino

@@ -20,10 +20,12 @@ funcgen gen;
 void setup()
 {
   Serial.begin(115200);
-  Serial.print("Start functionGeneratorPerformance - LIB VERSION: ");
+  Serial.println(__FILE__);
+  Serial.print("FUNCTIONGENERATOR_LIB_VERSION: ");
   Serial.println(FUNCTIONGENERATOR_LIB_VERSION);
+  Serial.println();
 
-  Serial.println("func \t\tusec\tmax calls/sec");
+  Serial.println("func \t\tusec\tmax calls/sec  (indicative)");
   y = analogRead(A0) / 1024;
   test_square();
   delay(10);
@@ -43,9 +45,15 @@ void setup()
   delay(10);
   test_zero();
   delay(10);
+  test_sinusDiode();
+  delay(10);
+  test_sinusRectified();
+  delay(10);
+  test_trapezium2();
+  delay(10);
   Serial.println();
 
-  Serial.println("t \t sqr\t saw\t tri\t sin\t str\t rnd\t line\t zero");
+  Serial.println("t \t sqr\t saw\t tri\t sin\t str\t rnd\t line\t zero\t sinD\t sinR\t trap");
   for (int i = -400; i < 400; i += 2)
   {
     float t = i * 0.01;
@@ -66,6 +74,12 @@ void setup()
     Serial.print(gen.line());
     Serial.print("\t");
     Serial.print(gen.zero());
+    Serial.print("\t");
+    Serial.print(gen.sinusDiode(t));
+    Serial.print("\t");
+    Serial.print(gen.sinusRectified(t));
+    Serial.print("\t");
+    Serial.print(gen.trapezium2(t));
     Serial.println();
   }
   Serial.println("\ndone...");
@@ -218,10 +232,57 @@ void test_zero()
 }
 
 
+void test_sinusDiode()
+{
+  start = micros();
+  for (int i = 0; i < 10000; i++)
+  {
+    t = gen.sinusDiode(i);
+  }
+  stop = micros();
+  Serial.print(__FUNCTION__);
+  Serial.print(":\t");
+  Serial.print((stop - start) / 10000.0);
+  Serial.print("\t");
+  Serial.println(1000000.0 / ((stop - start) / 10000.0));
+}
+
+
+void test_sinusRectified()
+{
+  start = micros();
+  for (int i = 0; i < 10000; i++)
+  {
+    t = gen.sinusRectified(i);
+  }
+  stop = micros();
+  Serial.print(__FUNCTION__);
+  Serial.print(":\t");
+  Serial.print((stop - start) / 10000.0);
+  Serial.print("\t");
+  Serial.println(1000000.0 / ((stop - start) / 10000.0));
+}
+
+
+void test_trapezium2()
+{
+  start = micros();
+  for (int i = 0; i < 10000; i++)
+  {
+    t = gen.trapezium2(i);
+  }
+  stop = micros();
+  Serial.print(__FUNCTION__);
+  Serial.print(":\t");
+  Serial.print((stop - start) / 10000.0);
+  Serial.print("\t");
+  Serial.println(1000000.0 / ((stop - start) / 10000.0));
+}
+
+
 void loop()
 {
 }
 
 
 //  -- END OF FILE --
-