Lab 2 JFETtransfercurve

7/31/2019 Lab 2 JFETtransfercurve

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Laboratory Activity 1:

PIC16F84A MicrocontrollerFaderan, Daniel Brian

Fernandez, Jose Carlos

BS Computer EngineeringAteneo de Manila University

Loyola Heights, Quezon City

I. OBJECTIVES

The goal of this experiment is to be able to explore the functions PIC16F84A Microcontroller and finally be able to

program it. The PIC16F84A should be programmed to be able to display a 4-bit output dependent on a user-controlled 2-bit

input.

II. INTRODUCTION

The PIC16F84A is a microcontroller in the PIC family. It has a total of 18 pins, 13 of which are I/O pins which we canuse, as seen in Figure 1. Using this microcontroller, we will use a total of 6 of the available I/O pins to create a circuit which uses

2 inputs in which the value is controlled from the switches of the Digital Kit provided in the laboratory which would then control4 outputs which will be noticed through the kits LEDs. Controlling the outputs will be handled by a program which will be

installed into the microcontroller.

The conditions of the program are as follows:

Input: Sw2 = 0 and Sw1 = 0, Output: LEDs = 0101

Input: Sw2 = 0 and Sw1 = 1, Output: LED values are rotating left with initial value of 0001.

Input: Sw2 = 1 and Sw1 = 0, Output: LED values are counting.

Input: Sw2 = 1 and Sw1 = 1, Output: LEDs are alternately blinking (i.e. 1001 0110)

III. METHODOLOGY

A circuit is built following the circuit diagram below:

Fig 1. PIC16F84A Microcontroller Circuit Diagram

Two RA pins(pin 17 & 18) were used as inputs whilst four RB pins(pins 6, 7, 8, 9) were used outputs during the

programming process. 2 input pins were attached to switches whilst 4 output pins were attached to LEDs. Below is the code for

the required program which was installed into the microcontroller(with comments as explanations):

//code startINCLUDE "P16F84.INC"list p=16F84

radix hex


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__config _XT_OSC & _PWRTE_ON & _WDT_OFF

PortB equ h'06' ;RB pins

PortA equ h'05' ;RA pins

status equ h'03'

trisb equ h'86'

trisa equ h'85'count1 equ h'0e'

count2 equ h'0f'

org 0x000bsf status,5

movlw 00h

movwf trisb

movlw 03h

movwf trisa

bcf status,5

start

BTFSS PortA, 0 ;check if binary value in pin 17 is either 1 or 0

goto sw

BTFSS PortA, 1 ;if pin 17 = 1, thengoto input01 ;if pin 18 = 0, goto rotating left LEDs

goto input11 ;if pin 18 = 1, goto alternately blinking LEDs

sw

BTFSS PortA, 1 ;else if pin 17 = 0, then

goto input00 ;if pin 18 = 0, goto still LEDs

goto input10 ;if pin 18 = 1, goto binary counting LEDsinput00 ;still LEDS

movlw b'0101'

movwf PortBcall delay

goto start

input01 ;rotating left LED light

movlw b'0001'


movlw b'0010'

movwf PortB

call delay

movlw b'0100'movwf PortB

call delay

movlw b'1000'movwf PortB

call delaygoto start

input10 ;binary counting LEDs

movlw b'0000'

movwf PortB

call delayinc1

incf PortB

call delay

BTFSS PortB, 0

goto inc1BTFSS PortB, 1

goto inc1

BTFSS PortB, 2

goto inc1

BTFSS PortB, 3goto inc1

goto start

input11 ;alternately blinking LEDs

movlw b'1001'


movlw b'0110'

movwf PortB

call delay

goto startdelay


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movlw h'ff' ;setup delay count value 1

movwf count1 ;count1 is slow counter loop1a decfsz count1,1 ;

goto labela ;still > 0

return ;count1 < 0 so get out of the delay loop

labela movlw h'ff' ;setup delay count value 2

movwf count2 ;count2 is fast counter inside count1 looploop2a decfsz count2,1 ;

goto loop2a ;still > 0 so stay in loop2

goto loop1a ;count1 < 0 go to loop1

end;//end code

IV. RESULTS & DISCUSSION

Below is the set-up for the microcontroller done according to the circuit diagram:

Fig 2. PIC16F84A Microcontroller Set-Up

Fig 2.1. Switches Designating Pin 17 & 18 With 0 Binary Value

Fig 2.2. Pin 17 = 0, Pin 18 = 0, Still LEDs Triggered

Figure 2.1 and 2.2 are samples taken from the experiments video documentary to indicate that the PIC is functioning

well and the program installed is working according to its predetermined conditions.

V. CONCLUSION AND RECOMMENDATION

The PIC16F84A is a good microcontroller to start out with because of its good number of I/O pins and wide range of

possible applications, although, it is limited to small-scale circuit technology like this lab experiment, for example. It is good for

similarly small applications and is great for laboratory practice even if programming it requires low-level programming language

like Assembly. Overall, this version from the PIC family is indeed useful.


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Lab 2 JFETtransfercurve