Edge Trigger Code

Replies

• 

  Harshad Italiya

  qaisarpk1

  hi every one..
  
  i want to make a up-down counter using 8051..
  two switches are connected with UC.
  one for up counting and one for down counting..
  now the problem is that if i press one switch only at once it count correctly but if
  switch is not released then it will not count only for once.....it count continuosly untill the switch is released.
  i want to make it edge triger mean if a switch is pressed it will count when switch is released. if switch is hold for long time ,it must have to count only once...
  
  i need c code or any algorithem ..
  
  i m using keil c compiler..
  
  thnx

  
  That is called KEY DEBOUNCE.
  
  what have you written? something like that? this is only if your switch is connected with Ground and you detect 0 at controller side.
  
  if(!SWITCH1)
  {
  count++;
  }
  
  Right?
  
  you can write
  while(!SWITCH) // in this case your execution waits untill you release the Key.
  {
  count++
  }