3:
If you like to develop a computer-based DAQ measurement system or that can provide several functions in a Smart Home System, such as climate control or gas leakage detection functions, answer the following for the climate control system function:
3.1 Draw the hardware connections of the system focusing on the pin connections of the system components, so that the system can provide the ‘Climate Control’
function. The available devices are: (5 marks)
Microprocessor-based system (Laptop/PC).
Interface board: NI USB DAQ.
LM35 Temperature sensor Humidity sensor
Micro-switches Variable resistor LEDs Relays
Multi-output power supply
Include any required passive electronic components
3.2 Draw a flowchart for a program that can achieve both the climate control and gas leakage detection functions. (4 marks)
3.3 What are the factors that should be considered when selecting a DAQ card?
(4 marks)
3.4 Discuss the signal aliasing problem and how you can overcome this effect; support your answer with figures and drawings (2 marks)
3.5 What are the steps of conversion of continuous signals to digital values (ADC)?
(2 marks)
3.6 Name four types of ADC’s and choose any two to compare between them; what is the ADC type that is used in NI DAQ’s? support your answer with figures and drawings (7 marks)
3.7 Compare between RTD (Resistance Type Device) and Thermocouples temperature sensors; support your answer with examples and drawings. The LM35 sensor can be classified as which type of temperature sensors? (5 marks)
3.8 Give examples of DAQ cards that can be used to measure the following properties and discuss the reasons for your selection.?
- Displacement
- Vibration
- Strain (6 marks)
Total 35 marks 4:
You are to develop a home security system that can be used to monitor a house of two doors and four windows. The output of the system should present the status of each location independently and should provide an audible warning in case of any problem – including the detection of smoke. The available devices are:
− PIC16F877 Microcontroller (given in Figure 4.1)
− two door push button switches
− four window push button switches
− one Motion Detector
− one smoke detector sensor
− eight LEDs
− one buzzer
− Include any passive electronic components required.
According to your study answer the following questions:
4.1 Draw a block diagram for the complete system. (4 marks)
4.2 Using the PIC16F877A microcontroller shown in Figure 4.1, draw the wiring diagram of the proposed system. Include any necessary electronic components required for the microcontroller to function correctly; state the function of each
element. (8 marks)
4.3 Draw a flowchart for a program that can achieve the above function. (4 marks)
4.4 Given the pin configuration of the PIC16F877A microcontroller (shown in Figure
4.1), describe the function of the following: (4 marks)
__________ __
- MCLR
- OSC1/OSC2
| – |
| RA0 |
| – |
| RD5 |
| ( |
| Figure |
| 4.1) |
| Total |
| 20 |
| marks |
