4017, RS232 and LEDs

Discussion in 'The Projects Forum' started by SunSatION, Dec 25, 2008.

  1. SunSatION

    Thread Starter New Member

    Aug 30, 2008

    Basically, I can't sleep so... :p

    I was thinking of a way how to control a number of LEDs using a serial port. I'm trying to set on a specific LED using a 4017 counter ( since that's the only tool I have around right now ). My idea was to use the "Request To Send" from the Serial Port to act as a Clock Input on the 4017 to set to the desire output pin. My question is, would a naked eye see the LEDs light up, let's say between Pin 0 to Pin 5 ( 1,2,3,4 )?

    Info : CD4017BC,5V using 9600 baud rate from the serial port.
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    Have you got the means of explicitly controlling the RTS line? If so, and you can insure the pin voltage will be acceptable to the CD4017, then yes.
  3. SunSatION

    Thread Starter New Member

    Aug 30, 2008
    So you'll be able to see the LEDs in between going on and off? That's bad :(
  4. SgtWookie


    Jul 17, 2007
    It sort of depends on how fast you're clocking it, but I'm afraid that even at 9600 baud you'll see the intermediate LEDs flash momentarily.

    If you want to be able to clock bits in without them displaying until commanded, you'll need to use a universal shift register instead.