// Tue 15 Mar 21:53:55 UTC 2022

// https://github.com/wa1tnr/wokwi_CircSimApps-a/tree/dvlp-aa/series-gg.d/timer-counter-b

// empty sketch


timer-counter-b.ino

Tue 15 Mar 21:53:55 UTC 2022

ATMega2560 board variant

  https://github.com/wa1tnr/wokwi_CircSimApps-a/tree/dvlp-bb/series-gg.d/timer-counter-b

SUCCESS IV (this very):

  https://wokwi.com/projects/326213297742283348

SUCCESS III:

  https://wokwi.com/projects/326210683296285266


SUCCESS II:

  https://wokwi.com/projects/326209618982208084

SUCCESS:

  https://wokwi.com/projects/326210683296285266

NEW:

  https://wokwi.com/projects/326154839088169556


OLDER:

(*Uno* based):

  https://wokwi.com/projects/326126843778302548

  https://wokwi.com/projects/326120084410991187

datasheet 2560:

  https://ww1.microchip.com/downloads/en/DeviceDoc/ATmega640-1280-1281-2560-2561-Datasheet-DS40002211A.pdf


 - - -


datasheet 328p:

  https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-7810-Automotive-Microcontrollers-ATmega328P_Datasheet.pdf

(see page 74+)

14.9 p. 84:

14.9 Register Description

p. 87:
Table 14-9 Clock Select Bit Description

16.1 p. 114:

16.1 Internal Clock Source

The Timer/Counter can be clocked directly by the system clock (by setting the CSn2:0 = 1). This provides the fastest operation, with a maximum Timer/Counter clock frequency equal to system clock frequency (fCLK_I/O). Alternatively, one of four taps from the prescaler can be used as a clock source. The prescaled clock has a frequency of either fCLK_I/O/8, fCLK_I/O/64, fCLK_I/O/256, or fCLK_I/O/1024.

END.


NOTE.md

diagram.json

// Tue 15 Mar 21:53:55 UTC 2022

// n_sketch_t-c-b.cpp

// https://github.com/wa1tnr/wokwi_CircSimApps-a/tree/dvlp-aa/series-gg.d/timer-counter-b

// NEXT_GEN (not here):
// https://wokwi.com/projects/326235653444469332

// SUCCESS (this very):

// https://wokwi.com/projects/326213297742283348


#include <Arduino.h>

const byte TONE = 88;

const byte BUZZER = 2;  // Timer 3 "B" output: OC3B

const long frequency = 50000L;  // Hz

const byte n =   233 ; // UNUSED

void setup_timer(void) {
  pinMode (BUZZER, OUTPUT);
  // tone(2, 500); while(-1); // test wiring

  // Arduino MEGA  2560 MCU:
  TCCR3A = 
        bit (COM3B1)
      | bit (WGM31)
      | bit (WGM30)
  ;
  // MODE 15 WGM33 32 31 and 30 all set
  TCCR3B = 
        bit (WGM33)
     |  bit (WGM32)
      | bit (CS32)
    //| bit (CS31)
      | bit (CS30)
  ;
  OCR3A = TONE; // RESPONSIVE! 21:48 UTC 15 Mar 2022
}

// cant see it so using piezo instead of LED

void cpl(int PIN) {
  bool state = digitalRead(PIN);
  state = !state;
  digitalWrite(PIN, state);
}

#define ON_TIME 250
#define OFF_TIME 1700

void blink(int PIN) {
  cpl(PIN);
  delay(ON_TIME);
  cpl(PIN);
  delay(OFF_TIME);
}

void setup_serial(void) {
  Serial.begin(115200);
  delay(400);
  while(!Serial) { delay(10); }
  Serial.write(' ');
}

const int LED_pin = 5;

void setup_gpio(void) {
  pinMode(LED_pin, OUTPUT);
  digitalWrite(LED_pin, LOW);
}

void setup() {
  setup_serial();
  setup_gpio();
  setup_timer();
}

void loop() {
  // put your main code here, to run repeatedly:
  blink(LED_pin);
}

#if 0
Timers and counters

    https://www.gammon.com.au/timers

The Atmega328 (as on the Arduino Uno) has three
timers/counters on-board the chip.

Timer 0 is set up by the init() function (which is
automatically called by the code generated by the
IDE, before setup() is called).

This is used to count approximately every millisecond.

This provides you with the figure that the millis()
function returns.


example sketch from Nick Gammon follows.

const byte LED_timed = 3;  // Timer 2 "B" output: OC2B

const long frequency = 50000L;  // Hz

void setup_timer(void) {
  pinMode (LED_timed, OUTPUT);

  TCCR2A = bit (WGM20) | bit (WGM21) | bit (COM2B1); // fast PWM, clear OC2B on compare
  TCCR2B = bit (WGM22) | bit (CS21);         // fast PWM, prescaler of 8
  OCR2A =  ((F_CPU / 8) / frequency) - 1;    // zero relative  
  OCR2B = ((OCR2A + 1) / 2) - 1;             // 50% duty cycle
}

void loop()
  {
  // do other stuff here
  }

#endif
// END.
