M.Sc. (Semester (CBCS) Examination Oct/Nov-2017
Electronic Science
MICROCONTROLLERS AND INTERFACING
Day Date: Thursday, 23-11-2017 Max. Marks: 70
Time: 10.30 AM to 01.00 PM
Instructions: Answer any five questions.
Questions 1 and 2 are compulsory.
Answer any three questions from Q.3 to Q.7.
Use of scientific calculator is allowed.
Q.1 Choose the alternatives given below. 08
In 8051 pins have no dual function.
PORT 0 PORT 1
PORT 2 PROT 3
The internal RAM location 01H of 8051 can also be accessed as
Register R1 of bank 0
Direct memory address 01H
Indirect memory address 01H using @RO
All of the above
The stack pointer of 8051 storing data on the stack.
Increments before Increments after
Decrements before Decrements after
The 8051 has bit-addressable area of bits.
8 16
128 256
The 8051 can access maximum bytes of external ROM and
external RAM respectively.
4K, 128 8K, 256
64K, 128 64K, 64K
I/O pins are required to connect matrix keypad of 16 keys.
4 8
12 16
sensor has the output scale factor of 10.0 mV/°c.
LM 35 Thermocouple
Thermistor LDR
The first line of characters is addressed at locations in 16*2 LCD.
00H-0FH 20H-2FH
80H-8FH C0H-CFH
State true or false. 06
The serial port of 8051 is full duplex.
The DJNZ instruction of 8051 tests 'Zero flag' to make decision.
DPTR is an 8-bit pointer.
External Access pin of 8051 is active low.
8051 I/O ports can directly drive DC motor.
The GSM module is used to build applications involving satellite based
navigation system.
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Q.2 Explain LCALL, ACALL, RET and RETI instructions of 8051. 04
With a neat diagram explain LED interfacing with 8051. 05
Give specifications of HY HS 220 module. 05
Q.3 List features of 8051 microcontroller. 05
Explain internal RAM organization of 8051. 05
Write a short note on PORT 3 of 8051. 04
Q.4 What is an Interrupt? What is the need of Interrupts? Explain the interrupt
mechanism of 8051.
08
Write a program to generate square wave on PORT 1 pin 1 (single pin) when
an external interrupt 0 (level sensitive) occurs.
06
Q.5 With a neat diagram explain interfacing of 8-channel ADC with 8051
microcontroller.
04
Write a program to read input voltages in the range of 0-5V of ADC input
channels and display these inputs in 'channel number: voltage' format.
10
Q.6 Design a 8051 microcontroller based system to measure and display the
temperature in degree Celsius and humidity on %RH.
10
How to measure current using microcontroller? 04
Q.7 What is GSM? Explain why and how to interface GSM module with the
microcontroller.
10
Explain any four AT commands supported by GSM module. 04