ENEL3CA / ENEL3DA Design 1 2023
Smart Lecture Venue Project
Project Description:
Teams of 4 students will design a system to monitor and control the lighting, temperature and
occupancy of a lecture venue. The current room occupancy and temperature will be displayed. An
alarm will sound if the maximum occupancy is exceeded. Lights will be turned off when room is empty
and the minimum amount of power will be used to maintain a constant level of illumination.
General Rules:
1. No part of the project may use programmable device, ie. no embedded (microcontrollers) or
external (PC/smartphone) based solutions. This purpose of this project is to give students
experience with basic analog and digital design.
2. Students may propose modifications or additions but MUST discuss these with the mentor and
have them approved in writing (email approval is sufficient). If what is required, or the
constraints are not clear, students should consult their mentor.
3. The project has been divided into 4 sub-systems, each of which will have individual specs. Each
sub-system is assigned to one student.
4. The final project must be integrated. The final prototype should be implemented on PCB.
5. Milestones must be completed to the satisfaction of mentor before students proceed.
Sub-systems:
The Switched-mode power supply Unit:
This will supply the required DC power for all sub-systems.
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Input: 9 V +- 1 V DC, output: 5VDC @ 100 mA max
No more than 10% change in voltage over entire range of input voltage and load conditions.
The power supply must be REGULATED, ie. the voltage maintained without human
intervention.
Min. 80% efficiency at full load.
Variable voltage mode: adjust from 0 to 5V.
Short circuit/overcurrent protection.
No SMPS “on-a-chip” solutions. Build from first principles.
The “People Counter” Unit:
This unit will track the number of people in the venue.
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Count up when a person enters, and count down when a person leaves
Maximum occupancy of 99 (needs to indicate overflow/underflow conditions)
Reset to 0 count on power-up
Consist of appropriate sensors with not less than 1m separating transmitter from receiver.
Sensing must reply on breaking of beams (ie. no mechanical switches, etc)
Mechanically robust and reliable operation; ie. insensitive to ambient light, etc.
Display and Alarm Unit :
This unit will display the occupancy and temperature; an alarm will sound if maximum
occupancy for the venue is exceeded.
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Alternate display of number of occupants / room temperature at 10 second intervals.
Maximum occupancy 99; Temperature range 15 to 40 C (received from Control Unit)
Alarm will sound if maximum occupancy is exceeded.
Alarm will sound if temperature exceeds 40 C.
Oscillator and buzzer (sufficiently loud).
No “single chip” solutions (design and build a solution not find a ready-made solution).
Control Unit:
This unit will handle all high voltage (220VAC) and control the lights and temperature.
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Control 60W 220VAC incandescent light bulb – turn on when occupancy is greater than 0 and off
when it is 0.
Automatic dimming to keep illumination at a constant level using minimum required power.
Manual override for light switch (always on/always off/automatic).
Measure temperature (pass this signal to display and alarm unit).
If temperature is above 40C, send alarm signal to display and alarm unit.
No electromechanical or solid state relays!
NOTE: The project requirements are subject to change. Minor modifications to the above document
aimed at clarifying or simplifying the project will be announced though the course Moodle site at
https://learn.ukzn.ac.za.