how to use internal PLL in arduino, How to reduce processing time

Hi, i am using arduino micro. i am using internal clock only, not using any crystal. now my program needs to respond to a serial query in less than 5ms. but my code takes 15ms. I am using polling method only.

i get all inputs to my arduino via serial only. So if i go for interrupt, Upon receiving an char in serial i have to ensure that the request to be served even if another char comes in. so inside every condition i need to disable interrupt , upon coming out i need to enable. but i dont have idea on how to do that. So tell me how to do that? Please any suggestion to reduce time

my code looks like follows,..

void setup() { Serial.begin(9600); } void loop { if(Serial.available>0) { char Input =; } if(Input == 'a') { // process 1 } if(Input =='b') { //process 2 } }

alagappan: void setup() { Serial.begin(9600); Serial.begin(115200); }

If the other side is capable of sending (so much) faster.



Please remember to use code tags when posting code

It's the code you did not post that is causing the problem.


This piece of code is very buggy:

char Input =; //makes Input known only within this block!
  //do all input processing here
//if(Input == 'a') //move all that stuff into above block

And don't disable interrupts unless really required, to access volatile variables. Else you'll miss all characters arriving while interrupts are disabled.