/*************************************************************************************************
                                      PROGRAMMINFO
**************************************************************************************************
Funktion: ESP32 Frequenzgererator mit OLED 1,3" Display und Ser. Monitor Konfiguration
Ti/Tp = 0-1023
Aufloesung 8-16 Bit
**************************************************************************************************
Version: 10.04.2022
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Board: ESP32vn IoT UNO V1.0.4
**************************************************************************************************
C++ Arduino IDE V1.8.13
**************************************************************************************************
Einstellungen:
https://dl.espressif.com/dl/package_esp32_index.json
http://dan.drown.org/stm32duino/package_STM32duino_index.json
https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_dev_index.json
**************************************************************************************************
**************************************************************************************************/

#include <Wire.h>
#include "SH1106.h"
#define LEDC_CHANNEL_0     0
#define LEDC_TIMER_13_BIT  13

//SSD1306  display(0x3C, 21,22);
SH1106  display(0x3C, 21,22);
unsigned int pwmpin = 27;
unsigned int freq = 1000;
unsigned int duty_set_min = 0;
unsigned int duty_set_max = 100;
unsigned int duty_timer = 100;
unsigned int duty_last = 100;
unsigned int resolution = 10;
unsigned int aresolution = pow(2,resolution)-1;
unsigned int rduty=map(duty_set_max, 0, aresolution, 0, 100);
hw_timer_t * timer = NULL;
volatile uint8_t stat = 0;

void IRAM_ATTR onTimer(){
  stat=1-stat;
  if (stat==1)duty_timer=duty_set_max;
  else if (stat==0)duty_timer=duty_set_min;

}
void setup()
{

Serial.begin(115200);
while (!Serial) {
}
delay(100);
  Serial.println(" ESP32 PWM GENERATOR");
  Serial.println(" Kommandos:");
  Serial.println(" 'f' aendere Frequenz");
  Serial.println(" 'd' aendere Ti/Tp");
  Serial.println(" 'r' aendere Aufloesung");
  Serial.println(" 'p' aendere GPIO");
  display.init();

ledcSetup(0, freq, resolution);
ledcAttachPin(pwmpin, 0);
ledcWrite(0, duty_set_max);
screen(pwmpin,freq,duty_set_max,rduty);

timer = timerBegin(1, 80, true);  // timer 0, MWDT clock period = 12.5 ns * TIMGn_Tx_WDT_CLK_PRESCALE -> 12.5 ns * 80 -> 1000 ns = 1 us, countUp
timerAttachInterrupt(timer, &onTimer, true); // edge (not level) triggered 
timerAlarmWrite(timer, 1000000, true); // 1000000 * 1 us = 1 s, autoreload true
timerAlarmEnable(timer); // enable

}

void loop()
{
if (duty_last==duty_timer){
}
else {
  duty_last=duty_timer;
  pwmsettings(pwmpin,freq,duty_last,resolution);
}
if (Serial.available()) {
    char cin = Serial.read();
    byte cin1;
    switch (cin) {
    case 'f':
      Serial.println("Neue Freqenz in Hz");
      while (!Serial.available());
      freq = Serial.parseInt();
                        pwmsettings(pwmpin,freq,duty_set_max,resolution);
                        Serial.print(" Neue Frequenz:");
                        Serial.print(freq);
                        Serial.println("Hz");
                        break;
    case 'd':
      Serial.print("Neue Ti/T (0-");
      Serial.print(aresolution);
      Serial.println(")");
      while (!Serial.available());
      duty_set_max = Serial.parseInt();
                        pwmsettings(pwmpin,freq,duty_set_max,resolution);
                        Serial.print("Neue Ti/T:");
                        Serial.println(duty_set_max);
                        break;
    case 'r':
      Serial.println("Neue Aufloesung (8-16)");
      while (!Serial.available());
      resolution = Serial.parseInt();
                        pwmsettings(pwmpin,freq,duty_set_max,resolution);
                        Serial.print("Neue Aufloesung:");
                        Serial.print(resolution);
                        Serial.println(" Bit Aufloesung");
                        break;
    case 'p':
      Serial.println("Neue Pin Nummer");
      while (!Serial.available());
      pwmpin = Serial.parseInt();
                        pwmsettings(pwmpin,freq,duty_set_max,resolution);
                        Serial.print("Neu Pin Nummer:");
                        Serial.println(pwmpin);
                        break;
}
}
}
void screen(unsigned int pwmpin,unsigned int freq, unsigned int duty_set_max,unsigned int rduty)
{
    display.clear();  
    display.setTextAlignment(TEXT_ALIGN_CENTER);
    display.setFont(ArialMT_Plain_10);
    display.drawString(64, 3, "PWM GENERATOR");
    display.setTextAlignment(TEXT_ALIGN_LEFT);
    display.drawString(2, 15, "Freq: " + String(freq)+"Hz");
    display.drawString(2, 27, "Ti / T: "+String(duty_set_max)+" / "+String(aresolution)+"  ("+String(rduty)+"%)");
    display.drawString(2, 39, "Aufloesung: "+String(resolution)+" Bit");
    display.drawString(2, 51, "Pin: "+String(pwmpin));
    display.display();
}
void pwmsettings(unsigned int pwmpin,unsigned int freq, unsigned int duty_set_max,unsigned int resolution)
{
aresolution = pow(2,resolution)-1;
rduty=map(duty_set_max, 0, aresolution, 0, 100);
ledcSetup(0, freq, resolution);
ledcAttachPin(pwmpin, 0);
ledcWrite(0, duty_set_max);
screen(pwmpin,freq,duty_set_max,rduty);    
}