Summary of Breadboard module for 18-pin PIC16F microcontrollers (PCB version)
This article describes designing a compact PCB breadboard module for 18-pin PIC16F microcontrollers (e.g., PIC16F628A, PIC16F1827). The author created a two-layer 5cm×~3.5cm board with an 18-pin DIP socket, resonator clock, switches, LEDs, ICSP header, I/O headers, and ground plane, had 10 PCBs manufactured affordably by Iteadstudio, and used DesignSpark PCB to generate Gerbers.
Parts used in the Breadboard module for 18-pin PIC16F microcontrollers (PCB version):
- 18-pin DIP socket (for 18-pin PIC microcontroller)
- 3-pin ceramic resonator (4.0 MHz)
- Two tact switches (6 mm × 6 mm, 2-pin)
- 2-pin dip switch
- Resistor 10 KΩ (two units)
- Resistor 470 Ω (two units)
- Capacitor 100 nF
- LED for power-on indicator
- LED for user output
- 5-pin ICSP header (for PICkit2/PICkit3)
- Header pins for Vcc, Gnd, PORTA (RA0–RA4) and PORTB (RB0–RB7)
- Two-layer PCB with copper pour ground plane
Because of their compact size, ease of use and many built-in peripherals, the 18-pin PIC16F series processors (PIC16F628A, PIC16F88, and now PIC16F1827/47) have always been my favorite microcontrollers. Many of my projects and tutorials written in this blog also use PIC16F628A and PIC16F1827 microcontrollers. As I will be using them more in the future too, I thought of making some PCB versions of my breadboard module for PIC16F628A with some modifications. I used Iteadstudio’s PCB prototyping service for this, and I would say the PCBs turned out really well for the price I paid. I used their 2 layer 5cm x 5cm service and got 10 PCBs for less than $15, including shipping to the United States.
Component layout and circuit diagram
The PCB dimension is approximately 5.0 cm x 3.5 cm and has got the following components:
- 18-pin DIP socket to hold an 18-pin PIC microcontroller
- 3-pin Ceramic resonator (4.0 MHz)
- Two tact switches (6 mm x 6mm, 2-pin type like this)
- 2-pin dip switch
- 4 resistors (two 10 KΩ, two 470 Ω)
- 1 capacitor (100 nF)
- 2 LEDs
- 5-pin ICSP header
- Header pins for Vcc, Gnd, PORTA, and PORTB pins
The layout of these components on the PCB is shown below. There are two tact switches on the board: one for reset and other for user input. Similarly, there are two LEDs: one for power-on indicator and the other for user output. The input tact switch and the output LED can be connected to RB0 and RB1 pins respectively through a 2-pin dip switch. The switch and the LED are useful for a quick test of the board. The microcontroller clock is derived using an external ceramic resonator having 3 pins with built-in load capacitors. PORTA (RA0-RA4) and PORTB (RB0-RB7) pins of the microcontroller are accessible for experimenting through header pins (male, female, or right-angled). A 5-pin header is also available for ICSP programming through a PICkit2 or PICkit3.
The circuit diagram of this breadboard module is provided below. It can also be constructed on a general purpose prototyping perforated circuit board just like my breadboard module for PIC16F628A.
PCB design
I designed a two layer PCB for this project using the DesignSpark PCB design software, which is free and easy to use. It also lets you create Gerber files of your designed PCB. The top and bottom layer of the PCB are shown below. I have used a copper pour on the bottom layer to create a ground plane. It could be done for the top layer too.
For more detail: Breadboard module for 18-pin PIC16F microcontrollers (PCB version)
- What microcontrollers is this PCB module intended for?
The module is intended for 18-pin PIC16F series microcontrollers such as PIC16F628A and PIC16F1827. - What is the PCB size?
The PCB dimension is approximately 5.0 cm × 3.5 cm and the author used a 5 cm × 5 cm service for fabrication. - What provides the clock for the microcontroller on the board?
The clock is provided by an external 3-pin ceramic resonator rated at 4.0 MHz with built-in load capacitors. - How can I program the PIC on this PCB?
The board includes a 5-pin ICSP header for programming with a PICkit2 or PICkit3. - Which pins are exposed for experiments?
PORTA (RA0–RA4) and PORTB (RB0–RB7) pins are accessible via header pins. - What switches are included and what are they for?
There are two tact switches (one for reset and one for user input) and a 2-pin dip switch to connect the input tact switch and output LED to RB0 and RB1 respectively. - What indicators are on the board?
There are two LEDs: one for power-on indication and one for user output. - What design software was used to create the PCB?
The PCB was designed using DesignSpark PCB, which can generate Gerber files. - Did the author use a ground plane?
Yes, a copper pour ground plane was used on the bottom layer; the author notes it could also be done on the top layer. - Where were the PCBs manufactured and what was the cost?
The PCBs were fabricated by Iteadstudio using their 2-layer 5 cm × 5 cm service; the author received 10 PCBs for less than $15 including shipping to the United States.
