PIC Experimenter's Board Manual

PIC Experimenter's board

Introduction
The PIC Experimenter's Board is a complete prototyping platform for the 16F8X, 16C55X, 16C62X, 16C7X and 16C8X family of 18-pin PIC microcontrollers. Its 168-point solderless connection area allows for quick and easy access to all Port A (RA0-RA4) and Port B (RB0-RB7) I/O lines. It includes an integrated 16x2 serial LCD display (optional backlight), which can be easily connected with one wire to any I/O line (or external source).

Use
The board can be powered by either a 9V battery or a AC/DC transformer. The power switch in the upper-right turns the board on and off (the power LED will light). The board also includes a reset button, for resetting the microcontroller. The LCD has its own power switch, located directly above the LCD. If your LCD is backlit, the backlight switch is located above the LCD power switch (note that using the backlight increases current draw, and therefore will drain a battery quicker). The prototyping area is laid out like a typical solderless breadboard. For those who have not dabbled in electronics we will describe the proto-typing section on the PIC Experimenters board and wire a simple LED project. The proto-typing are is located at the lower left corner of the PIC Experimenters Board, see figure 1.

Figure 1

There is an open 18-pin socket to hold the microcontroller being developed. The proto-typing area is similar in design and function to solderless breadboards; see Figure 2.

You can breadboard (assemble and connect) electronic components and electronic circuits into the proto-typing area without soldering. The proto-typing area is reusable; you can change, modify or remove circuit components at any time. This makes it easy to correct any wiring errors. A cutaway of the prototyping area is shown in Figure 3.

The square holes shown in the area are sockets. When a wire or pin is inserted into a hole, it makes electrical contact with the underlying metal strip. The holes are spaced so that integrated circuits and many other components can be plugged right in.

The internal electrical connection structure of the proto-typing area is shown in Figure 4 (lower left).

Figure 5 (lower right) shows the prototyping area broken up into banks. The banks make it easier to identify different sections in the prototyping area.

Looking at Figure 5, to the right, we see at the top of the proto-typing area, the columns of Bank 1 are labeled with the pins assignments from the 16F84. These columns are directly connected to those microcontroller pins. Connecting a wire or device to any of the three sockets in a particular column is electrically connecting that wire or device to that I/O pin of the 16F84. Bank 2 provides fourteen individual four-socket columns. The four sockets aligned in each individual column are electrically connected. The individual columns are separate electrically from one another. Bank 3 is the same as Bank 2. The last row labeled GND (ground) is electrically connected across the entire row. There are an additional three ground sockets at the top of bank 1. A +5V power is available from a 4-socket column adjacent to bank 1.

Simple Experiment:
We shall wire a simple experiment to illustrate the usage of the experimenters proto-typing area; blinking an LED. The following is a small PICBasic Program and PICBasic Pro Program to blink an LED on PIN RB1.

The complete schematic for this experiment is shown in Figure 6. Aside from a programmed 16F84 we only need two other components; a 470-ohm ¼ watt resistor and a sub-miniature LED. All the other components needed to make the 16F84 work are already hardwired on the PIC Experimenters Board.

The LED has two terminals, one longer than the other. On the schematic it is shown as a diode. The longer terminal on the LED is positive, shown in the legend of figure 7.

To wire this circuit, connect one lead of the ¼ watt resistor into one of the RB1 sockets. Connect the other lead of the ¼ watt resistor into a socket in Bank 2.

Take the positive lead of the LED and plug it into a socket in the same column as the one containing the resistor lead. Connect the opposite lead of the LED and plug it into one of the ground sockets at the bottom, see figure 7.

Plug the programmed 16F84 microcontroller into the 18 pin socket on the PIC Experimenters Board and turn on the power. The LED should begin blinking on for ¼ second then off for a ¼ second. This on-off cycle (blinking) continually repeats.

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