K8048 - Demo2.asm, Flashing LEDs, Breadboard example

Kits Microcontroller Programmer - Experimenting Project
1

Hi i have successfully got the K8040 working for some time now. I had no success in programming 12F629… just a lot of issues as described else where on the net.

so i thought i’d carry on with the 16F627A as supplied with the kit. It works fine with demo2.asm and i’d thought i’d actually try the chip on a breadboard.

After, initially having no output, i changed the oscillator settings from _XT_OSC to _INTRC_OSC_CLKOUT… i am not expert, but from studying the circuit diagram in the assembly guide pdf, i saw that the circuit was using the external oscillator. This cured the problem to the point where the circuit was running and the switches obey their commands… but

there is some wierd ’ grounding’ issues going on the board only seems to board when i touch a bare contact… i believe having the bare bones with NO components is not helping…

QUESTION:
Does anyone know where there is a circuit diagram for the demo2.asm circuit on a breadboard? My circuit does work, i just wanted to try and build it ‘properly’

notes: my circuit is just the pic16F627A in a breadboard with the six LEDs attached accordingly.

PIN
4 5v+
5 5v -
6 LED
7 LED
8 LED
9 LED
10 LED
11 LED
14 5v +

2
  • Did you add a capacitor of 100nF between PIC pins 5 and 14 (supply)? If this cap is not present, strange things can happen.
  • I assume that “LED” in fact means “LED in series with a resistor of approx 500R”.
  • What switches are you talking about? You only mention LED’s in your connection list.
    If you mean pushbuttons like on the K8048, then do not forget their resistors (10K) to ground like on the K8048 board.