update build-CI + badges + minor edits (#3)

* upgrade build-CI + badges + readme.md
* add mode flag to reverse sawtooth() and  stair()

Author: RobTillaart

.arduino-ci.yml

@@ -2,8 +2,13 @@ compile:
   # Choosing to run compilation tests on 2 different Arduino platforms
   platforms:
     - uno
-    - leonardo
-    - due
-    - zero
+    # - due
+    # - zero
+    # - leonardo
+    - m4
+    - esp32
+    # - esp8266
+    # - mega2560
+    # Declaring Dependent Arduino Libraries (to be installed via the Arduino Library Manager)
   libraries:
-    - "MCP4725"
+    - "MCP4725"

.github/workflows/arduino_test_runner.yml

@@ -4,10 +4,14 @@ name: Arduino CI
 on: [push, pull_request]
 
 jobs:
-  arduino_ci:
+  runTest:
     runs-on: ubuntu-latest
 
     steps:
       - uses: actions/checkout@v2
-      - uses: Arduino-CI/action@master
-          #   Arduino-CI/action@v0.1.1
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.6
+      - run: |
+          gem install arduino_ci
+          arduino_ci.rb

README.md

@@ -1,15 +1,62 @@
 
 [![Arduino CI](https://github.com/RobTillaart/FunctionGenerator/workflows/Arduino%20CI/badge.svg)](https://github.com/marketplace/actions/arduino_ci)
+[![Arduino-lint](https://github.com/RobTillaart/FunctionGenerator/actions/workflows/arduino-lint.yml/badge.svg)](https://github.com/RobTillaart/FunctionGenerator/actions/workflows/arduino-lint.yml)
+[![JSON check](https://github.com/RobTillaart/FunctionGenerator/actions/workflows/jsoncheck.yml/badge.svg)](https://github.com/RobTillaart/FunctionGenerator/actions/workflows/jsoncheck.yml)
 [![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/RobTillaart/FunctionGenerator/blob/master/LICENSE)
 [![GitHub release](https://img.shields.io/github/release/RobTillaart/FunctionGenerator.svg?maxAge=3600)](https://github.com/RobTillaart/FunctionGenerator/releases)
 
+
 # FunctionGenerator
 
-Arduino library to generate wave forms (nummeric) for a DAC
+Arduino library to generate (numeric) wave forms for a DAC
+
 
 ## Description
 
-TODO.
+This library presents a class for a function generator in software. 
+It is typical used to control one or more DAC's.
+To maximize signal quality one has to apply all (or most) processor power 
+to calculate new values over and over again to get enough resolution. 
+In practice the generator is useful for low frequencies, 
+0.01 - 25 Hz, depending on waveform and processor and number of DAC's.
+(see indication below).
+
+Note: this class generates float values, performance wise this can be optimized,
+to achieve higher speeds at cost of accuracy / precision.
+
+
+## Performance
+
+Indication of what performance can be expected (based upon 0.2.1 version).  
+Note that the values need to be transported to a DAC or serial port too.  
+Numbers based on performance example, for one single signal.
+
+| Processor    | Clock    | Waveform | usec/calls | max freq |
+|:-------------|---------:|:---------|-----------:|---------:|
+| Arduino UNO  | 16 MHz   | sawtooth |  62        |  60 Hz   |
+| Arduino UNO  | 16 MHz   | triangle |  74        |  50 Hz   |
+| Arduino UNO  | 16 MHz   | square   |  53        |  1000 Hz |
+| Arduino UNO  | 16 MHz   | sinus    |  164       |  25 Hz   |
+| Arduino UNO  | 16 MHz   | stair    |  81        |  50 Hz   |
+| Arduino UNO  | 16 MHz   | random   |  37        |  1000 Hz |
+|              |          |          |            |          |
+| ESP32        | 240 MHz  | sawtooth |  3.8       |  1000 Hz |
+| ESP32        | 240 MHz  | triangle |  3.9       |  1000 Hz |
+| ESP32        | 240 MHz  | square   |  2.8       |  1000 Hz |
+| ESP32        | 240 MHz  | sinus    |  13.6      |  250 Hz  |
+| ESP32        | 240 MHz  | stair    |  4.8       |  800 Hz  |
+| ESP32        | 240 MHz  | random   |  1.3       |  1000 Hz |
+
+
+- assumption minimal 250 samples per period to get a smooth signal.
+  if a rougher signal is OK, higher frequencies are possible.
+- ESP32 can do more calculations however 1000 Hz seems to be a nice 
+  upper limit for a software based function generator.
+- if one wants to control multiple DAC's one need to divide the numbers.
+
+
+Note: hardware function generator https://github.com/RobTillaart/AD985X
+
 
 ## Interface
 
@@ -18,48 +65,76 @@ TODO.
 - **funcgen(float period = 1.0, float amplitude = 1.0, float phase = 0.0, float yShift = 0.0)**
 All parameters can be set in the constructor but also later in configuration.
 
+
 ### Configuration
 
-- **void  setPeriod(float period = 1.0)**  // seconds
-- **float getPeriod**
-- **void  setFrequency(float freq = 1.0)**  // Hertz
-- **float getFrequency()**
-- **void  setAmplitude(float ampl = 1.0)**  // -
-- **float getAmplitude()**
-- **void  setPhase(float phase = 0.0)**     // phase of period
-- **float getPhase()**
-- **void  setYShift(float yShift = 0.0)**   // shift in amplitude, zero point.
-- **float getYShift()**
+- **void  setPeriod(float period = 1.0)** set the period of the wave in seconds. 
+- **float getPeriod()** returns the set period.
+- **void  setFrequency(float frequency = 1.0)** set the frequency of the wave in Hertz (1/s).
+- **float getFrequency()** returns the set frequency.
+- **void  setAmplitude(float amplitude = 1.0)** sets the amplitude of the wave. TODO point to point?
+Setting the amplitude to 0 gives ?what? 
+- **float getAmplitude()** returns the set amplitude.
+- **void  setPhase(float phase = 0.0)** shifts the phase of the wave. Will only be noticeable when 
+compared with other waves.
+- **float getPhase()** returns the set phase.
+- **void  setYShift(float yShift = 0.0)** sets an Y-shift in amplitude, allows to set some zero point.
+- **float getYShift()** returns the set Y-shift.
+
 
 ### Wave forms
 
 t is time in seconds
-- **float sawtooth(float t)**
-- **float triangle(float t)**
-- **float square(float t)**
-- **float sinus(float t)**
-- **float stair(float t, uint16_t steps = 8)**
-- **float random()**
-- **float line()**
-- **float zero()**
-
-Line() and zero() are functions that can be used
-to drive a constant voltage from a DAC and can be 
-used to calibrate the generator / DAC combination.
+
+- **float sawtooth(float t, uint8_t mode = 0)** mode == 0 (default) ==>  sawtooth /|. mode == 1 ==> sawtooth |\.
+- **float triangle(float t)** triangle form, duty cycle 50%.
+- **float square(float t)** square wave with duty cycle 50%.
+- **float sinus(float t)** sinus wave, has no duty cycle. 
+- **float stair(float t, uint16_t steps = 8, uint8_t mode = 0)** mode = 0 ==> steps up, mode = 1 steps down.
+- **float random()** noise generation.
+- **float line()** constant voltage line
+- **float zero()** constant zero.
+
+Line() and zero() are functions that can be used to drive a constant voltage from a DAC 
+and can be used to calibrate the generator / DAC combination.
+
 
 ## Operational
 
 See examples.
 
-## TODO
 
-ideas for the future...
+## Future
+
+
+#### waveforms
+
+- square duty-cycle  (will be slower!)
+- triangle duty-cycle (makes sawtooth a special triangle)
+- trapezium wave (would merge square and triangle and sawtooth)
 
+#### investigate
+
+- duty-cycle for sinus what does it mean. move peak.
+- white noise, pink noise etc.
+- investigate algorithms for performance gains (DAC specific values 10-12-16 bit)
+- Amplitude modulation ?
+- external clock to synchronize two or more sw function generators.
+- RC function curve.
+- heartbeat curve?
+- record a signal and play back
+
+#### misc
+
+- stand-alone functions in separate .h?
+- mapping to voltage function.
+- check for synergy with https://github.com/RobTillaart/AD985X
+
+#### examples
+
+- example ESP32 version as separate task...
 - example with DAC. 8 12 16 bit.
-- example with potmeters for 4 parameters
-- RC function
-- Trapezium 
-- Sawtooth reverse?
-- play "recording"
+- example with potentiometers for 4 parameters
+
 
 

examples/functionGenerator/functionGenerator.ino

@@ -7,13 +7,16 @@
 //     URL: https://github.com/RobTillaart/FunctionGenerator
 //
 
+
 #include "functionGenerator.h"
 
+
 funcgen gen;
 
 uint32_t lastTime = 0;
 char choice = '0';
 
+
 void setup()
 {
   Serial.begin(500000);
@@ -24,6 +27,7 @@ void setup()
   gen.setAmplitude(50);
 }
 
+
 void loop()
 {
   if (Serial.available())
@@ -54,4 +58,6 @@ void loop()
   }
 }
 
-// END OF FILE
+
+// -- END OF FILE --
+

examples/functionGeneratorDuoPlot/functionGeneratorDuoPlot.ino

@@ -14,6 +14,7 @@
 funcgen gen1;
 funcgen gen2;
 
+
 void setup()
 {
   Serial.begin(115200);
@@ -31,6 +32,7 @@ void setup()
   gen2.setYShift(25);
 }
 
+
 void loop()
 {
   float t = millis() * 0.001;
@@ -44,4 +46,6 @@ void loop()
   Serial.println();
 }
 
-// END OF FILE
+
+// -- END OF FILE --
+

examples/functionGeneratorPerformance/functionGeneratorPerformance.ino

@@ -7,6 +7,7 @@
 //     URL: https://github.com/RobTillaart/FunctionGenerator
 //
 
+
 #include "functionGenerator.h"
 
 uint32_t start;
@@ -17,6 +18,7 @@ volatile float y;
 
 funcgen gen;
 
+
 void setup()
 {
   Serial.begin(115200);
@@ -87,6 +89,7 @@ void test_square()
   Serial.println(1000000.0 / ((stop - start) / 10000.0));
 }
 
+
 void test_sawtooth()
 {
   start = micros();
@@ -102,6 +105,7 @@ void test_sawtooth()
   Serial.println(1000000.0 / ((stop - start) / 10000.0));
 }
 
+
 void test_triangle()
 {
   start = micros();
@@ -117,6 +121,7 @@ void test_triangle()
   Serial.println(1000000.0 / ((stop - start) / 10000.0));
 }
 
+
 void test_sinus()
 {
   start = micros();
@@ -132,6 +137,7 @@ void test_sinus()
   Serial.println(1000000.0 / ((stop - start) / 10000.0));
 }
 
+
 void test_stair()
 {
   start = micros();
@@ -147,6 +153,7 @@ void test_stair()
   Serial.println(1000000.0 / ((stop - start) / 10000.0));
 }
 
+
 void test_random()
 {
   start = micros();
@@ -162,6 +169,7 @@ void test_random()
   Serial.println(1000000.0 / ((stop - start) / 10000.0));
 }
 
+
 void test_line()
 {
   start = micros();
@@ -177,6 +185,7 @@ void test_line()
   Serial.println(1000000.0 / ((stop - start) / 10000.0));
 }
 
+
 void test_zero()
 {
   start = micros();
@@ -192,8 +201,11 @@ void test_zero()
   Serial.println(1000000.0 / ((stop - start) / 10000.0));
 }
 
+
 void loop()
 {
 }
 
-// END OF FILE
+
+// -- END OF FILE --
+