Week 12 (Final Semester)

Title: Final test

Objective:

• To make sure all the circuit running as plan
• To make sure the hardware suitable for the project
• To prepared for the viva

Content:

On this week task, the project will be tested thoroughly. After connecting all the wiring at the circuit and connect all the battery the testing begin. First switch on the circuit at the remote control car, which is the receiver circuit. The orange led at the remote control car will be turn on to indicate the receiver is on. Then switch on the transmitter circuit inside the casing, the orange led turn on to indicate the transmitter is on. When the transmitter circuit is on, the door lock of the project automatically goes up. Which means, the car is unlock. It because the transmitter is on the range of receiver can detect, which is about 5 meters. When the transmitter is taken away from the receiver, the door lock is automatically locked. This means that the circuit and the door lock mechanism works fine

door lock mechanism locked when the transmitter out of range that the receiver can detect

 

door lock mechanism unlocked when the transmitter in range that the receiver can detect

The second phase of the final testing is to test the car light (white led) and the engine (motor). The light and the motor has its own switch. When the transmitter is on the range, switch on the switch of motor and the light, and then bring the transmitter outside the range. The motor and the light is automatically switch off when that happen. This prove that the project is successfully worked

 

The light and the motor is off when the transmitter is out of the range

The light and the motor is on when the transmitter is in the range

Analysis:

There are slight problem with the project where there is no more space for the battery to fit in the car, so for the solution, the battery will be outside when the demonstration. the switch also cannot attach at the car because the casing of the is quite soft. The switch will be hanging outside the car. And also, when the motor running, the tire of the car also running, so, something must be put under the back of the car to avoid the car from moving.

Conclusion:

Overall this project is function and successful. Even though the hardware is not perfect, but it considered well turned of project. Now the project is finish, the last thing that need to be done is design a poster for the viva.

Week 11 (Final Semester)

Title: Hardware

Objective:

• To customizing hardware to the project specification
• To interface between circuit and hardware
• To learn all the skill in making a good hardware for the project

Content:

This week is focusing on customizing the hardware base on the project specification. The hardware also appropriate with the circuit because the circuit need to fit in the hardware. For this project, the main hardware is the remote control car. From the remote control car, the function of prototype is:

• white led = car light
• motor = car engine

And for the car lock mechanism, the actual car lock is used just like the figure at the bottom. The door lock as attach to the remote control car.

Receiver circuit + hardware

For the receiver circuit, the circuit itself is put in the car. All the component and the origin circuit is be taken out, so the inner of the remote control car is emptied. After that the receiver circuit is attach to the inner of the remote control car just like the bottom figure

Transmitter Circuit + Hardware

For the transmitter circuit, the circuit is put inside the casing. The casing itself must be small to make sure the driver easy to carry it around. The casing need to drilled a hole for the LED and the switch for the project specification.

Analysis:

When putting the circuit in the hardware, it is necessary to keep the bottom of the circuit safe from scratch, because it may unconnected the path of component of the of the PCB circuit. The battery also must be covered, must avoid direct contact between the circuit and the component because it may causing dysfunctional item.

Conclusion:

The hardware need to be choose wisely for comfortable work and demonstration. For the hardware for the circuit, it must be not too small because it may broke the circuit, also not too large because it can be hard to carry. Now the hardware is complete, testing of the project will begin in next week

Week 10 (Final Semester)

Title: Track checking and soldering

Objective:

• To troubleshoot the PCB traces
• To assembly the components
• To solders the component
• To master the soldering skill

Content:

It is important for the designer troubleshoots the PCB traces before assembly and solders the components. Two possible things might happen in the PCB traces: one is short circuit and the other one is open circuit. Short circuit means two PCB traces are touching to each other. This causes high current flows in the entire circuit and burn out some of the low rating components. Open circuit means there is no connection. When power is on, the PCB does not response. This might be the problem of open circuit. Short circuit can be troubleshoot by using PCB cutter to separate the two touching traces. Open circuit can be troubleshoot by using jumper wire to make the connection between two traces.

After all tracks are repaired, the component can be replace on PCB and start solder one by on using soldering iron and lead. The figure on the bottom is the component that need to be use when soldering

Soldering Iron

                                                                Lead

Analysis:

There are a few things that needs to be considered while soldering, the important thing is of course the safety precautions. These are the list of safety precaution that must follow when soldering

First a few safety precautions:

• Never touch the element or tip of the soldering iron.
  They are very hot (about 400°C) and will give you a nasty burn.
• Take great care to avoid touching the mains flex with the tip of the iron.
  The iron should have a heatproof flex for extra protection. An ordinary plastic flex will melt immediately if touched by a hot iron and there is a serious risk of burns and electric shock.
• Always return the soldering iron to its stand when not in use.
  Never put it down on your workbench, even for a moment!
• Work in a well-ventilated area.
  The smoke formed as you melt solder is mostly from the flux and quite irritating. Avoid breathing it by keeping you head to the side of, not above, your work.
• Wash your hands after using solder.
  Solder contains lead which is a poisonous metal.

Preparing the soldering iron:

• Place the soldering iron in its stand and plug in.
  The iron will take a few minutes to reach its operating temperature of about 400°C.
• Dampen the sponge in the stand.
  The best way to do this is to lift it out the stand and hold it under a cold tap for a moment, then squeeze to remove excess water. It should be damp, not dripping wet.
• Wait a few minutes for the soldering iron to warm up.
  You can check if it is ready by trying to melt a little solder on the tip.
• Wipe the tip of the iron on the damp sponge.
  This will clean the tip.
• Melt a little solder on the tip of the iron.
  This is called 'tinning' and it will help the heat to flow from the iron's tip to the joint. It only needs to be done when you plug in the iron, and occasionally while soldering if you need to wipe the tip clean on the sponge.

Ready to start soldering:

• Hold the soldering iron like a pen, near the base of the handle.
  Imagine you are going to write your name! Remember to never touch the hot element or tip.
• Touch the soldering iron onto the joint to be made.
  Make sure it touches both the component lead and the track. Hold the tip there for a few seconds and...
• Feed a little solder onto the joint.
  It should flow smoothly onto the lead and track to form a volcano shape as shown in the diagram. Apply the solder to the joint, not the iron.
• Remove the solder, then the iron, while keeping the joint still.
  Allow the joint a few seconds to cool before you move the circuit board.
• Inspect the joint closely.
  It should look shiny and have a 'volcano' shape. If not, you will need to reheat it and feed in a little more solder. This time ensure that both the lead and track are heated fully before applying solder.

Conclusion

Now the circuit is complete and after wiring it, the circuit is ready to use. Now, all need to be done is the hardware part of the project. The hardware will be prepared on the next week.

Week 9 (Final Semester)

Title: Drilling


Objective:

• To make a hole on PCB for the component to fit in
• To master the skill  on drilling the PCB

Content:

Drill size is important to make correct holes for the correct electronic components. Difference components have difference size of leads and hence need difference pad sizes and hole. Following figure shows the difference size of drill bits and following table shows the functions of each bit. 

Difference size of drill bits and their functions. 

Analysis:

There are certain things must be considered while drilling. The most importance thing is make sure the drill bits did not cuts the diagram on the PCB. It may unconnected the circuit of PCB. And make sure the size of the drill bits is proportional for the functions just like on the table.

Conclusion:

If the drill accidentally damage the diagram on the circuit, the circuit must be fix with the soldering iron to connect back what the damage that has been done. After successfully finish the drilling, the next thing to do is to track checking and soldering the component. 

Week 8 (Final Semester)

Title: PCB fabrication

Objective:

• To copy the diagram of the circuit on the PCB
• To master on how to fabric the PCB

Content:

PCB fabrication

1.    PCB Drawing: PCB drawing is designed using Protel DXP 2005. Once the PCB layout has been correctly design, it is now prints out the layout on the A4 size transparent OHP paper. Note that, two types of printers are allowed to print the PCB layout, one is laser printer and the other is carbon type of printer such as Photostat machine. Inkjet and dot matrix type of printer will not work.

2.    Prepare tools required:

þ Fluorescent light

þ UV PCB

þ Marker Pen

þ Blade

þ OHP transparent paper

þ Iron (III) chloride, FeCl₃ acid

þ Clean water

þ Thinner

þ Plastic Container

þ Laser printer

þ PCB cutter and trimmer

þ Soldering gun

þ Soldering lead

3.    PCB Cutting: Cut photo PCB size according to the film size.

4.    PCB Photo Etching: Expose the photo PCB in photo etching kit for 8-10minutes.

5.    PCB Developing: Wash the PCB using PCB developer (white powder) for 2 min.

6.    Acid Etching: Etching is a process that removes materials from such us unwanted copper from the PCB surface to achieve circuit design requirements. The etching process used in this project is called chemical etch or pattern etch.

Once the image printed on PCB copper board, now prepare the iron (III) chloride, FeCl₃ solution and ready to do the etching. Add in hot water (80C) and shake the water until you see unused part is ‘washed’ and left only the tracks. The etching process takes around 30 min.

 

7.    Thinner Washing:

This is a process to remove the black ink on the PCB board. The black ink has to remove in order to solder the components. The green coating on PCB can be removed by alcoholic solution and leaving only the PCB trace. After remove the black ink, the PCB is then send for cleaning using normal water.

Analysis:

This project has two circuit, the circuit can do at the same time at the step acid etching and thinner washing to elude the waste. The acid etching is quite dangerous task, so must take safety precaution while doing it such as wearing a glove to cover the hand and the mask to evade from smelling the acid. If the route of the diagram is accidently  cut off, use the soldering iron to connect it back.

Conclusion:

This part of task is really important because the circuit is the heart of the project to operate. Without the circuit, the project cannot operate. After the fabrication is finish, the next thing to for the next week is drilling

Week 7 (Final Semester)

Title: Burn the program into PIC

Objective:

• To download the PIC program to PIC microcontroller
• To master the step

Content:

Step to download the PIC program to PIC microcontroller

1.    Connect PIC programmer to computer via serial port / USB port.

2.    Insert PIC into the programmer socket

3.   Copy ‘Winpic800’ folder to Desktop.

4.    Look for Winpic800.exe in the folder.

 5. Double click Winpic800.exe to start the program.

6. Select the proper PIC name in the top right combo box

7.   Open the .hex file which you want to download into PIC e.g. if your .c filename is ‘abc.c’,    suppose you need to download ‘abc.hex’ into PIC.

Analysis:

For this project there are two PIC need to be burn. Even they are different PIC, the way to download the program on it still the same. 

Conclusion:

The step of downloading the PIC program to PIC microcontroller must be follow, or it will lead to another problem such as PIC dysfunction or even broken PIC. So, it must be done with care.

Week 6 (Final Semester)

Title: Testing the components

Objective:

• To evaluate whether the component function or dysfunction
• To evade any major problem related to the component 

Content:

For this week certain component were tested whether it got problem or not. Not all the test are recorded but here one of the component is being test

This is the video where the lock mechanism is being test. By using 12 volt battery the lock mechanism work fine, there is no dysfunction from this component.

Analysis:

Not all the component can test directly like PIC, it need to be burn and see the PIC work fine or has the problem working. So all that can do is just hoping the component like PIC works fine after the burning.

Conclusion:

This part of task is important to evade any major problem afterwards. This is the safety precaution that need to be take. Finish with this task, the next week will begin to burning the PIC