Digital Visitor Counter

Digital visitor counter is a reliable circuit that takes over the task of counting Number of Persons/ Visitors in the Room very accurately. When anybody enters into the Room then the Counter is Incremented by one and when any one leaves the room then the Counter is Decremented by One. The total number of Persons inside the Room is displayed on the seven segment displays.
The microprocessor do the above job it receives the signals from the sensors, and this signals operated under the control of software which is stored in the Memory. The sensors are made with help of LDRs which are Light Dependent Resistors, whose Resistance is inversely proportional to the Light falling on it. The Laser Torch is used as the Light source and it is focused on the LDRs, the Microprocessor continuously watches the LDRs.

Digital gates Emulator

This project “Digital gates Emulator” is used to emulate the basic gates such us NOT, OR, AND. The system has the selector switch by which we can select any gate. The system has two inputs and one output. We use two SPDT switches for the inputs and for the output we use an LED. The gate selection can be done by the selector switch and it is also indicated on separate LED’s. There are three LED’s provided on the board for the gates NOT, OR, AND. The corresponding LED will glow for the corresponding gate. The main operation is done by the Microprocessor through its ports using the PPI (Programmable Peripheral Interface) IC8255. The microprocessor gets the input through the ports and it will produce the output according to the gate selected.

Automatic Plant Irrigator

The Project presented here waters our plants regularly when you are out for vocation. The circuit comprises of sensor parts built using op-amp IC LM324. Op-amp’s are configured here as a comparator. Two stiff copper wires (for one sensor) are inserte The Project presented here waters our plants regularly when you are out for vocation. The circuit comprises of sensor parts built using op-amp IC LM324. Op-amp’s are configured here as a comparator. Two stiff copper wires (for one sensor) are inserted in the soil to sense the whether the Soil is wet or dry. The Microprocessor was used to control the whole system. It monitors the sensors through the programmable peripheral interface (PPI) IC 8255. When more than two sensors sense the dry condition, then the Microprocessor will switch on the motor and it will switch off the motor when all the sensors goes wet. The Microprocessor does the above job by receiving the signals from the sensors through the PPI, and this signals operated under the control of software which is stored in ROM. We are using the 8 bit Microprocessor 8055 and the programmable peripheral interface IC 8255.d in the soil to sense the whether the Soil is wet or dry. The Microprocessor was used to control the whole system. It monitors the sensors through the programmable peripheral interface (PPI) IC 8255. When more than two sensors sense the dry condition, then the Microprocessor will switch on the motor and it will switch off the motor when all the sensors goes wet. The Microprocessor does the above job by receiving the signals from the sensors through the PPI, and this signals operated under the control of software which is stored in ROM. We are using the 8 bit Microprocessor 8055 and the programmable peripheral interface IC 8255.

Automatic Night Lamp with Morning Alarm

This Project “Automatic Night Lamp with Morning Alarm” was developed using Microprocessor. It is the Heart of the system. The sensors are made with help of LDR which are Light Dependent Resistors, whose Resistance is inversely proportional to the Light falling on it. The LDR converts the light energy into electrical energy and this variable electrical energy was converted into digital signal (0 or 1) by using the timer IC555. The Timer IC output goes low when light falls on the LDR and the timer IC output goes high when the LDR was placed in dark.

Access Control System

This project Access Control System is used in the places where we need more security. It can also used to secure lockers and other protective doors. The system comprises a number keypad and the keypads are connected to the 8 bit microprocessor 8085 through the programmable peripheral IC 8255. This is one of the popular microprocessor.
The microprocessor continuously monitor the keypad and if somebody enters the password it will check the entered password with the password which was stored in the memory and if it they are same then the microprocessor will switch on the device.
In our Project we are controlling a electrical device. The password can be an four digit number. If we enter the correct password then the microprocessor will switch on the load. If we want to switch off the load simply press the digit 0 in the keypad.

Write a program to shift an eight bit data four bits right. Assume that data is in register C.

Source program:

MOV A, C

RAR

RAR

RAR

RAR

MOV C, A

HLT

Statement:Write a program to shift a 16 bit data, 1 bit right. Assume that data is in BC register pair.

Source program:

MOV A, B

RAR

MOV B, A

MOV A, C

RAR

MOV C, A

HLT

Two digit BCD number is stored in memory location 4200H. Unpack the BCD number and store the two digits in memory locations 4300H and 4301H such that

Sample problem

(4200H) = 58

Result = (4300H) = 08 and

(4301H) = 05

Source program

LDA 4200H : Get the packed BCD number

ANI FOH : Mask lower nibble

RRC

RRC

RRC

RRC : Adjust higher BCD digit as a lower digit

STA 4301H : Store the partial result

LDA 4200H : .Get the original BCD number

ANI OFH : Mask higher nibble

STA 4201H : Store the result

HLT : Terminate program execution