Analog to digital converter with timer 1 ctc mode

Using Arduino Programming Questions
1

i´m making an analog to digital converter with timer 1 ctc mode and it shows me these message (data section exceeds available space in board)

2

@retgui1221, your topic has been moved to a more suitable location on the forum as this has absolutely nothing to do with Avrdude, stk500 or Bootloader issues.

Can't view the TinkerCAD page without registering :angry:

Not sure but I think that the message sounds like your ran out of flash memory.

3

Yes it rans out of memory, what can i do?
You have to create an account in tinkercad and then you can have access to it.

4

No idea; any option to select a board with more memory?

Not planning to do that any time soon. You have the code, why not post it here (don't forget code tags)?

5 
volatile boolean isrOnB = false;
volatile boolean aReady;
volatile boolean myFileDo = false;
volatile char buffA[2049];
volatile char buffB[2049];
volatile int buffCnt = 0;

void setupISR()
{
 Serial.println(F("enter setupISR())"));
  cli();//disable interrupts  
  
  //      *** ADC SETUP ***
  
  ADCSRA = 0; // clear before adding bits
  
  ADCSRB = 0; // clear before adding bits
  ADMUX |= (1 << MUX0); //setting input pin A7
  ADMUX |= (1 << MUX1); //setting input pin A7
  ADMUX |= (1 << MUX2); //set input pin A7
  ADMUX |= (1 << ADLAR); //left align the ADC value- so we can read highest 8 bits from ADCH register only
  
  bitSet(ADMUX, REFS0); // reference range = ground to AVCC (Analog VCC)
  //ADCSRA |= (1 << ADPS1) | (1 << ADPS2); //set ADC clock
  ADCSRA |= (1 << ADIE); //enable interrupts when measurement complete
  //ADCSRA |= (1 << ADEN); //enable ADC  //why this line stops it?
  //bitSet(ADCSRA,ADSC); //start ADC measurements

  //================================================
  
  //   *** TIMER1 INTERRUPT SETUP ***
  
  TCCR1A = 0;// set entire TCCR1A register to 0
  TCCR1B = 0;// same for TCCR1B
  TCNT1  = 0;//initialize counter value to 0
  OCR1A = 221;// how high to count before intterrupt occurs (must be < 65536)
  TCCR1B |= (1 << WGM12); // turn on CTC (Clear Timer on Compare) mode
  TCCR1B |= (1 << CS11);                  // divide by 1
  TIMSK1 |= (1 << OCIE1A);// enable timer compare interrupt

  sei();//enable interrupts
  Serial.println(F("exit setupISR()"));
}

ISR(TIMER1_COMPA_vect)
{
  isrOnB = true;
    if(aReady)
      buffA[buffCnt]=ADCH;
    else
      buffB[buffCnt]=ADCH;
  if (buffCnt == 2047)
  {
    buffCnt = 0;
    aReady = !aReady;
    myFileDo = true;
  }
  else
    buffCnt++;
  bitSet(ADCSRA,ADSC); //start ADC measurements
}

void doFile()
{
  myFileDo = false;
  if (aReady)
    Serial.println(F("Process buffB")); // Actually, "myFile.read(buffB,2048);" in my full sketch.
  else
    Serial.println(F("Process buffA")); // Actually, "myFile.read(buffA,2048);" in my full sketch.
}

void setup()
{
  Serial.begin(9600);
  setupISR();
}

void loop()
{
  if (isrOnB)
  {
    isrOnB = false;
    Serial.println(F("isrOnB == true"));
  }
  if (myFileDo)
    doFile();
  Serial.print(F("."));
}
6

I used pin A0 instead of A7 that why CS11

7

That's a lot of memory. You will need at least a Mega to run the sketch.

8

It looks like you are trying to read the ADC at 72 kHz! I don't see where you are setting the ADC clock to get that speed.

It takes 13 clock cycles to get a reading. To get 72 kHz readings you have to clock the ADC at 936 kHz or faster. You can set the clock to 1 MHz using the /16 prescale. You lose 4.5 bits of accuracy so the bottom 2.5 bits of your 8-bit samples will be unreliable.

I would use free-running mode (start a new ADC conversion as soon as a conversion is complete) and use the Conversion Complete interrupt for timing.

9

If you meant "divide by 1" you want CS10, not CS11. Setting CS11 will divide by 8, I think.

10

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