Introduction

The author has recently started working with the smaller, 8 pin, PIC devices. To facilitate development it was decided to create a small development PCB, as an alternative to using a solderless breadboard. The design aims were as shown here:
 

• Be capable of supporting the PIC12F675/12F629
• In circuit programmable using the PICKIT2/3 programmer.
• Be able to mechanically support the PIC12F675 ICD module.
• Provide 2-4 switched inputs.
• Provide LED outputs.
• Small PCB.
• Provide user access to GPIO pins and
• Powered from a +5V supply.

This is the assembled PCB, click to enlarge the photo.

Schematic design

The schematic is shown here, double click to see full size.

The PIC12F675 uses the internal oscillator.
The transistor circuit connected to the GP5/CLKIN input as I wanted the ability to invert an incoming clock signal.

PCB design

The PCB design uses a single sided PCB, the size is 30x55mm and is easily produced using homebrew PCB materials and processes. The PCB layout is shown here, double click to expand.

Download the design

To download the EAGLE CAD design, which includes the schematics and PCB, click here (65K zip).

Bill of Materials

Part	Value	Device	Description
C1	100n	C-EU050-035X075	CAPACITOR, European symbol
C3	10u	CPOL-EUE2.5-5	10uF 16V electrolytiic capacitor
D1	1N4148	1N4148DO35-7	Signal diode
IC1	PIC12F675P	PIC12F675P	8-Pin FLASH-Based 8-Bit CMOS Microcontroller
J1		JACK-PMS	2.1mm diameter power socket
JP1		PINHD-1X6	Pin header, 6 way right angle
JP2		PINHD-1X2	Pin header, 2 way
JP3		PINHD-1X2	Pin header, 2 way
LED1		LED3MM	Yellow LED
LED2		LED3MM	Green LED
R1	2K2	R-EU_0204/7	Resistor, 1/4 watt, 5% tolerance, 2K2
R2	2K2	R-EU_0204/7	Resistor, 1/4 watt, 5% tolerance, 2K2
R3	2K2	R-EU_0204/7	Resistor, 1/4 watt, 5% tolerance, 2K2
R4	10K	R-EU_0204/7	Resistor, 1/4 watt, 5% tolerance, 2K2
R5	2K2	R-EU_0204/7	Resistor, 1/4 watt, 5% tolerance, 2K2
RN1		G04R	SIL resistor network, 5 pin 4 commoned resistors
S1		DIP04YL	4 way DIL switch
T1	BC547	BC547	NPN TRANSISTOR

Test software

A simple LED flashing program, written using the Boost C compiler, is available here. A hex image is included so that you can program the chip without needing access to the compiler.

Updated 02 May 2011