Microtronics Pakistan | www.electronicspk.com| PIC Lab II Manual [2]
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ongratulations on purchase of PIC Lab-II development board. The board supports most com-
monly used 40 Pin Mid range PIC microcontroller units, and has on-board many commonly used
peripheral devices. All I/O lines are available through separate, well marked headers for daugh-
ter boards, or projects. Every I/O line group is provided with a set of power supply, so that the
daughter board can be powered up from the motherboard.
Salient Features of Board.
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Socket for 40 Pin PIC Microcontrollers (16F87x, 18FXXX)
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Changeable Crystal Oscillator (20MHz standard)
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5 Push Switches
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1 16x2 Character LCD
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USART (RS-232 Module)
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I2C EEPROM
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1 PIZO Buzzer
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In Circuit Serial programming / Debugging Support
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8 LED indicators
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38KHz Modulated Infra Red Sensor
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Connector for two Analog Inputs
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Connector for Hardware driven PWM
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Connector for T0CKI
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Connector for I2C Bus
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All I/O lines available through Headers
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On Board regulated 5V 1A power supply.
Power Supply
The board uses 5V regulated power supply, in order to assure a constant supply of 5V, we recommend a
power source more than 5V. The recommendation is 9V at least 300mA load. If you are going to drive an
external load through the board, like motor, or LEDs etc, make sure that the supply current is appropriate.
In that case we recommend 9V-12V DC adapter, 800mA to 1000mA.
The adapter must have center pin supplying Positive. Reverse polarity is checked however. There is a
blocking diode, which will not allow the reverse polarity to reach the board. There is an On/OFF switch,
and a Power-ON LED indicator. The Voltage regulator IC, 7805, is rated as 1A, and gets heat up if heavy
load is put on it, or if a voltage adapter of more than 9V is used. The regulated is fitted with commercial
heat sink.
The Microcontroller
The board contains a socket for 40-Pin PIC microcontroller. Board comes with standard PIC 16F877A mi-
crocontroller. However if you want to change, lets say to 18F452, simply take the IC out of socket and in-
sert the one of your choice.
The Oscillator Circuit
The oscillator circuit consists of a crystal oscillator and two 22pF capacitors. The crystal oscillator is not
fixed soldered, rather there is a base, into which it can be inserted. The board comes with 20MHz crystal,
however if you want to change this to another frequency, just pull it out and insert the new one.
PIC 18F series are capable of multiplying the clock frequency by 4, to generate an internal high frequency
oscillator. They can run at a maximum of 40MHz, therefore using a 10MHz crystal, along with enabling an
internal PLL, will give a speed of 40MHz.