Execution time on AtMega32

[leo6002]

I made my own arduino board using atmega32 following this schematic:

I'm wondering, how much time does it take for atmega32 to complete one operation(eg. add up two numbers in a for loop)

I tried testing myself. I modified timer one library so it uses pin b1 on atmega32 and wrote this code:

#include <TimerOneMighty.h>

int cnt = 0;
int i = 1;

void setup() {
  Serial.begin(9600);
  Timer1.initialize(10000000);
  Timer1.attachInterrupt(print);

}

void loop() {
  while(i == 1){
    cnt++;
    return;
  }
  if(i == 0){
    Serial.println(cnt);
    i = 1;
    cnt = 0;
  }
  

}

void print(){
  i = 0;
}

After that, all I did was change timer interrupt values from 10us to 1 000 000us and got values like this:

10us; cnt == 2
100us; cnt == 10-67
1 000us; cnt == 126-735
10 000us; cnt == 7 435-7 436
100 000us; cnt == 10 432-10 433
1 000 000us; cnt == 24 760-24 761

[gilshultz]

I can't answer as asked. You need to specify the clock speed, this determines the cycle time of the microprocessor. Then you run it in a loop, that is software, what is the code look like. Do you have background interrupts going, that can cause time variations. There is a lot more information needed. Depending on the numbers, you can do a register to register add, that only takes one CPU cycle. You need to define one complete operation, everything in the loop takes time.

[leo6002]

I have a 16MHz oscillator. I would need to add up two numbers from 300 to 2000 inside of a around 10ms for 10ish seconds. Will the atmega32 or 64 be fast enough?

[jremington]

Adding two 16 bit integers takes less than one microsecond on an ATmega32 with 16 MHz clock.

[leo6002]

Thanks for the information, it helps a lot. Do you maybe know how long does it take to do a digital/analog write and/or read?

[jremington]

Using Arduino default timing, analogRead() takes about 110 microseconds on most AVR-based processors.

You should be looking at the ATmega32 data sheet for the basic timing information.

[leo6002]

Thanks for the answer, I’ll take a look at a datasheet.