This document provides instructions for a laboratory experiment on a PIC microcontroller involving EEPROM, analog to digital conversion, and LCD display. The objectives are to understand EEPROM, ADC functionality and configuration. Experiments include writing and reading EEPROM, reading analog voltage with ADC and displaying on LCD, and programming a digital thermometer to read temperature from a sensor. Circuits include EEPROM with LEDs and ADC reading a potentiometer voltage to display on LCD. Exercises involve writing to all EEPROM addresses, displaying measured voltages, and programming a temperature display.

1. CENTRE OF DIPLOMA STUDIES
COMPUTER ADDED DESIGN LABORATORY
LABORATORY INSTRUCTION SHEET
DEK 3133
Subject Code and Name
MICROCONTROLLER
Experiment Code 06
Experiment Title Introduction to EEPROM & ADC
Course Code DET/DEE/DEX

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SUBJECT INFORMATION
SUBJECT : DEK 3133 MICROCONTROLLER
TOPIC : Lab 6 – Introduction to PIC EEPROM and Analog Digital Converter.
AIM To apply the knowledge and understanding on how to read/write the PIC’s EEPROM and how
to apply Analog Digital Converter (ADC)
1 OBJECTIVES
1.1 To understand the design of keypad.
1.2 To determine and analyze the function of keypad.
1.3 To understand the configuration of LCD.
2 EQUIPMENT
2.1 PIC Development Board – PICDEV
2.2 PIC16F877A (4Mhz Fosc)
2.3 MPLAB IDE Program
2.4 Mikro C
2.5 Proteus
2.6 The PIC Development Board User manual
2.7 Power supply 9V
3 THEORY
3.1 EEPROM
The EEPROM of PIC can be 1,000,000 erase/write cycle and Data EEPROM Retention can reach over 40
years. The data EEPROM and Flash program memory is readable and writable during normal operation (over
the full VDD range). This memory is not directly mapped in the register file space. Instead, it is indirectly
addressed through the Special Function Registers. There are six SFRs used to read and write this memory:
• EECON1
• EECON2
• EEDATA
• EEDATH
• EEADR
• EEADRH

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When interfacing to the data memory block, EEDATA holds the 8-bit data for read/write and EEADR holds
the address of the EEPROM location being accessed. The PIC16F877A have 256 bytes of data EEPROM. So
that the address of EEPROM is 00h FFh or 0 255
3.2 EEPROM IN C PROGRAMMING
MikroC includes two library for comfortable work with EEPROM. It can be use to read and write the
EEPROM easily. There library routines are:
Eeprom_Read(unsigned int address);
i.e: result = Eeprom_Read(0x3F); //Read the content of address 3F and put it in variable “result”.
Or the address can be write in decimal value, i.e : result = Eeprom_Read(63)
Eeprom_Write(unsigned int address, unsigned short data)
i.e: Eeprom_Write(0x3F, 1234); // Save/Write a value of “1234” into EEPROM at address 3F.
Or the address can be write in decimal value, i.e : Eeprom_Write(63,1234)
3.3 ANALOG DIGITAL CONVERTER (ADC)
Analog-to –Digital converters are among the most widely used devices for data acquisition. Digital computers
use binary (discrete) values, but in the physical world everything is analog (continuous). Temperature, pressure
(wind or liquid), humidity, and velocity are a few examples of physical quantities that we deal with every day.
A physical quantity is converted to electrical (voltage, current) signals using a device called a transducer.
Transducers are also referred to as sensors. Sensors for temperature, velocity, pressure, light, and many other
natural quantities produce an output that is voltage (or current). Therefore, we need an analog to digital
converter to translate the analog signals to digital numbers so that the microcontroller can read and process
them. See the figure below:
Microcontroller Connection to Sensor via ADC
3.4 ADC FOR PIC16F877A
The PIC16F877A has eight input pins for analog digital conversions. The conversion of an analog input signal
results in a corresponding 10-bit digital number. By selecting voltage references Vref- and Vref+, the minimal
resolution or quality of conversion may be adjusted to various needs. The ADC module has four registers.
These registers are:
• A/D Result High Register (ADRESH)
• A/D Result Low Register (ADRESL)
• A/D Control Register 0 (ADCON0)
• A/D Control Register 1 (ADCON1)

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3.5 ADC RESOLUTION
PIC16F877A has 10-bit resolution. So the number of steps is: 1024 = (0000000000 1111111111). When
Vref 5V(internal voltage supply) is used, the step size is 5V/1024 = 4.88mV. So it’s mean that every bit
increment is equal of single step voltage increment ~ 4.88mV.
For example to calculate the binary value of ADC that use Vref = 5V and the analog input = 1.7V is by using
the formula below.
Dout = Vin / Step Size. Dout = 1.7V / 4.88mV = 348.36 348 0101011100
Then the value of conversion is stores into the ADC registers (ADRESL and ADRESH) as shown in table
below.
10-bit ADC result
ADRESH ADRESL
01 01011100
ADC result is set to right justify
3.6 ADC IN C PROGRAMMING
ADC (Analog to Digital Converter) module is available with a number of PIC MCU models. Library function
Adc_Read is included to provide you comfortable work with the module.
Adc_Read(unsigned short channel)
i.e: adcresult = Adc_Read(0); //Read the 10bits of conversion value from PORTA.F0 and put into
//variable “adcresult”
Before using the function, be sure to configure the appropriate TRISA bits to designate the pins as input. Also,
configure the desired pin as analog input, and set Vref (voltage reference value).

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4 ATTENTION
4.1 Do not move any IC or device inside the board without any order from your instructor.
5 EXPERIMENT PROCEDURE
5.1.1 Before test your source code on the PIC development board, please make sure the jumper
5.1 EEPROM (Attachment Circuit 1: EEPROM and 8 LEDs)
connection of LED1 LED8 is .
5.1.2 The code below is show how to WRITE the data into the EEPROM at address 10h, 11h,
12h and 13h. Then READ the data at each address to show at PORTB every 1 second.
Type the code below and test the code on the PIC board and Proteus (See Circuit 1)
5.1.3 Write your observations.

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5.1.4 Using Proteus, you can see the content of EEPROM at specific address by Debug Watch
Window.
5.1.5 Right click and select “Add
Items (By Address)”
5.1.6 Then select PIC CPU EPROM
Memory –U1.
5.2 Exercise 1
Write a C program (using Loop programming = FOR or WHILE) to write the entire EEPROM
space (0x00h 0xFFh or 0 255) with data “00110011”. Draw a flowchart.
5.3.1 Before test your source code on the PIC development board, please make sure the jumper
5.3 Analog Digital Converter (Attachment Circuit 2: ADC and LCD)
connection of LCD is connected. Also make sure the jumper pin of RA0 is connected to
Variable Resistor (VR1). The detail jumper connections are shown below:
LCD Analog Input
LCDE B1 VR1 A0
LCDRW B2
LCDRS B3
LCDD4 B4
LCDD5 B5
LCDD6 B6
LCDD7 B7

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5.3.2 The code below is shows how the PIC read the input voltage at PORTA.F0 and display the
converted value in decimal to the LCD. The voltage reference used is Vref = 5V. Type the
code below and test the code on the PIC board and Proteus (See Circuit 2)
5.3.3 Write you observations.
5.4.1 Base on Circuit2; Write a C program that show on LCD the voltage value of analog input.
5.4 Exercise 2
The analog input is between 0v 5V. Use step size =
4.88mV to multiply with conversion value. In C
programming use
to convert the floating number to text so that it
can be shown in LCD. Click on MikroC for more
helps and examples. Draw a flowchart.

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5.5 Exercise 3 (Attachment Circuit 2)
Figure of Digital Thermometer
Base of figure above (Digital Thermometer), there is a temperature sensor that measures a
temperature value from 0 – 100 °C. The output from
the temperature sensor is a voltage value (0V – 5V).
Write a C program to show on the LCD the
Temperature value in degree Celsius. Draw a
flowchart.
Calculation Example:
0v 0°C, 2.5V 50°C, 5V 100°C.
Calculation Detail:
If the output voltage from sensors is 2.5V, find the ADC value and temperature value? Vref
used is +5V.
Voltage Step Size = 5V / 1024 = 4.88 mV
Use formula to calculate ADC
» ADC = Vin / Step Size = 2.5V / 4.88mV = 512.295082 = 512 (1000000000)
To get back °Celsius from ADC value:
From the formula:
Vin = ADC x Step Size = 512 x 4.88mV = 2.49856V
Temperature = (2.49856V / 5V) x 100°C = 49.9712 °C

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6 REPORT PREPARATION AND SCHEMA.
(1) 2 persons for 1 report.
(2) Due date to send report is 1 weeks after lab date.
(3) Report schema following below requirements:
Lab report cover sheet for 1st page.
Objective, theory, equipments for the 2nd page. (5) (5M)
Observations. (10)
1.EEPROM and LEDs observation from 5.1.3 (5 M)
2.ADC to LCD observation from 5.3.3 (5 M )
Result. (65)
1. Exercise 1 source code & Flow Chart (10 M)
2. Exercise 2 source code & Flow Chart (20 M)
3. Exercise 3 source code & Flow chart (35 M )
Discussion. (10)
1. A given memory of EEPROM has 12 address pins and 8 data pins. Find the size of EEPROM?(5 M)
2. Give two examples of devices that use Analog Digital Converter.(5 M)
Conclusions. (10)

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7 CIRCUITS ATTACMENT
Circuit 1: EEPROM and 8 LED

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Circuit 2: ADC and LCD