MQ-LIT-463a

Interested:

Questions:

• markquinn2000@eircom.net asks:

  I am doing a project with a 16c74 and I need to record and display the sequence if which I recieve a 100ms pulse on 20 different inputs. Can any one help

  Ha, I am a student doing a project where I need to record the sequence in which I recieve 20 input 100mS pulses and dispaly the sequence. I know it sounds easy but I do not have much experience in C programming, If anyone thinks they can help me i would be very grateful

  I have designed a timer device(displaying 60 leds) using a PIC16F84, 8 latches 74LS373, and a demultiplexer 74Ls138.

  I'm using the De-multiplexer 74ls138, connecting pins A0,A1,A2 & E1 to the PIC pins RA1-RA3 to be able to select a particular latch (LE) I'm using 8 latches for displaying the 60 leds. Pin RA0 is connected to a push button. Pins RB0-RB7 are connected to the input pins of the latch 74ls373 (hold & display) and the output to the led through a 270 ohms resistor.

  My question is after initialising the PIC, what instructions can I write in order to select a particular latch,(using the 74ls138) so that it can light the leds at an interval of 1 second?