WEEK 6 : PCB DEVELOPMENT

First of all, i would like to show our block diagram for this wind speed meter.

As referred  to the block diagram above, there are 4 main part in this circuit. First is control circuit where this circuit contain a PIC16F877A where this PIC will generate a pulse signal that will be transmitted to the ultrasonic transmission and reception circuit. In ultrasonic transmission and reception circuit, the signal will be routed to the transducer. After that the transducer will detect the feedback from the speed of wind if there is any changes during the transmitting and receiving signal process. So that, the feedback will be send back to the ultrasonic circuit and the circuit will amplify the feedback and redirect back to control circuit and the result will be display on 16x2 LCD.



PCB DEVELOPMENT

So after we have done with our schematic diagram last week, now we are going to do the next process of putting our circuit on Printed Circuit Board(PCB). In this process, we required to follow every step on doing the PCB. There are 6 steps on doing this PCB Development:

1. PCB Layout

- The PCB layout is a mirrored positive one - black on white. Mirrored as viewed from the silkscreen top (component) side. The PCB layout is printed 1:1 on paper by means of a laser printer or copier machine. The laser printer or copier toner will not run out when it gets wet or oily. The ink of an inkjet paper print does run out and inkjet printers are therefore useless with the described method. So this my PCB Layout:

ULTRASONIC TRANSMISSION AND RECEPTION  CIRCUIT

CONTROL AND DISPLAY CIRCUIT

2. PCB Preparation

For this process, we are going to use the Overhead projection paper (OHP) and print our PCB Layout on this paper using Laser-jet Printer.Then we move to the next step

3. PCB UV Exposure

In this process, we are going to exposed our PCB to the Ultraviolet using a UV Box. For this particular process, what we have to do is we stick our PCB layout that we already printed on OHP paper to this PCB board. Then we put this PCB board in the machine and set the time to 60 seconds. Then wait till the process finished.

Then we moved to the next process which will be continue next week.

WEEK 5 : CIRCUIT CORRECTION

             Sorry for being late on giving an update for my Final Year Project. After me and my partner have a discussion with our supervisor Miss Norrulhoda, she asked that we need to divide our task into two part which is hardware and software. So after a discussion, i decided to take responsibility on finishing the hardware part for this project and Zaheerudin will take care about the software part.
              Actually there is a problem occurred when we purchasing the component that we need for this project  where we cannot find the IC for Microcontroller which is using PIC 16F628. So after we asked our supervisor, we decided to used another microcontroller of PIC 16F877A and because of this problem, we have to redraw another circuit that compatible with the microcontroller. So after working on for the new circuit this is the result and we still don't now either this circuit is suited with the old one or not.

ultrasonic schematic:-

control and display function schematic:-

Thanks for everyone that help us to complete this redraw process. Now i will give a list of the components used in this new circuit.

RESISTOR(Quantity)

- 2.2K(2)
- 2.7K(2)
- 10K(2)
- 100K(3)
- 1K(5)
- 330R(1)
- 1M(1)
- 4.7K(1)
- 10R(1)

POTENTIOMETER
- 10K min. preset. round

CAPACITORS(Quantity)

- 100n(7)
- 100u(1)

SEMICONDUCTORS(Quantity)

- 1N4007 Silicon Rectifier(3)
- BC 547 npn Transistor(3)
- LM311 Voltage Comparator(1)
- LED red(1), green(1)
- PIC16F877A(1)
- 78L05 voltage regulator(1)

MISCELLANEOUS(Quantity)

- push-to-make switch(1)
- Resonator 4M(1)
- JHD 16x2 LCD(1)
- 40 KHz ultrasonic transducer(transmitter and receiver pair)(1)
- Reset button(1)
- Buzzer(1)

All above is the component used in this circuit. So that mean we have to go back to Jalan Pasar and  buy all this thing. That all for this week. I will give a new update for this project time to time. I hope all the readers can give comments on what we are doing now because seriously i need all that for my learning process. Thank you very much.

WEEK 4 : PURCHASES OF COMPONENTS

For this particular week, me and my FYP partner Zaheerudin went to Jalan Pasar located near Kampung Pandan. Our plan for this week is to browse and purchase the hardware equipments which are required to build our Wind Speed Meter

LIST OF ITEMS TO BUY

We then reach Jalan Pasar  and went to Maplin Electronics Sdn Bhd. Maplin Electronics Sdn Bhd is one of the leading and have a reputation of having a variety of resistors, potentiometers, capacitors and semiconductors. Plus since the price they offer is much cheaper.

After spending a few hours there, we managed to complete buying all the electronic components which are needed to build our Wind Speed Meter. Below were some of the item that we bought during our time at Maplin Electronics Sdn Bhd. Below are the equipments that we bought at Maplin's.

And to make it clear that we actually bought those stuff, below are the pictures of purchase.

WEEK 3 : INTRODUCTION

Assalamualaikum to all viewers. This is the updated for our FYP. We are being supervised by our lecturer Miss Norrolhoda, lecturer of electrical section. Before we proceed to other stage of making our project we would like to briefly explain about our project and we hope it can make people understand how this project function as a title given. Firstly we would like to talk about what is wind speed meter and how many types of wind speed meter and then we will explain about the circuit functionality. A wind speed meter or other named anemometer is a device that is used to measuring a speed of wind. the word anemometer came from greek word anemos mean wind. This device is commonly used in meteorology or aerodynamics measurement instrument.   The first known description of an anemometer was given by  Leon Battista Alberti around 1450. There is two classes of anemometer. Those that measure wind speed and those that measure wind pressure but nowadays an anemometer have both information. There is a lot of anemometers :-

1. cup anemometers
2. windmill anemometers
3. hot wire anemometers
4. laser doppler anemometers
5. sonic anemometers

For this project we are using the sonic or ultrasonic method in our project. Now we would like to explain how this ultrasonic anemometer functioned. An  ultrasonic anemometer uses sound to measure wind speed. It sends a sound signal from a fixed transmitter to a fixed receiver, and by measuring the time it takes for the sound to arrive, can compute the speed of sound. Wind speed will increase or decrease the speed of sound depending on whether it is a tail wind or a head wind. By measuring the speed of sound in both directions the wind speed along that axis can be calculated from the difference of the two measurements. A two axis or three axis instrument can measure total wind speed. For more information you can watch this video to understand more about how it work.

 

 So that is how the ultrasonic anemometer and ultrasonic theory worked. Now we will explain how our circuit of ultrasonic anemometer function based on schematic diagram.

 Figure 1 is a schematic for ultrasonic transmission and reception circuit diagram for this anemometer. As you can see there is two transducer X3 and X4 used in this circuit as an interchangeable transmitter and receiver. The transducer operate at the usual ultrasonic frequency o 40kHz. The transmission pulses are generated by a PIC microcontroller that you can see in figure 2. The route that the pulses take through IC3 is selected by the logic level applied to its pin 10, also controlled by PIC. So when pin 10 held low, the pulses are routed from IC3 pin 3 to pin 1, and out to transducer X3. Then the pulses transmitted to transducer X4 that acted as receiver at this time. Now the received pulses from transducer X4 are routed to IC3 pin 12 and then the pulses will pass through the analogue amplification circuit. When IC3 pin 10 is held high, the pulses are routed from IC3 pin 3 to pin 5, and this time the transducer X4 become a transmitter and transmitted the pulses to transducer X3 that become a receiver. The pulses pass via pin 14 to pin 13 and so out to the amplifier. Then the pulses from this ultrasonic circuit will to PIC and we can see the output displayed on the LCD display. Figure 2 shows the control circuit for this ultrasonic anemometer. This control circuit is using the PIC 16F628 to generating and sending pulses to the ultrasonic transducer, and for timing the return of the received signal. Then the result of its calculation are output to the 2-line 16-character alphanumeric LCD label as X2. The PIC is operated at 20 MHz set by the crystal X1 in conjunction with capacitors C3 and C4. For power source, this circuit is using a 9V PP3 battery to powered it. Although any DC supply between 7V and about 15V could be used and it will be regulated down to 5V by regulator IC2. Capacitors C1 and C2 encourage stability in the power lines. That's all for this time, we give an update for our FYP next time. Thanks for spend your time to view this blog. Assalamualaikum.