Chan's Kingdom

A Buck Converter Power Supply

This project has been in my mind for a long time. I have always wanted an easy to use power supply, without resorting to Arduino for a 5V supply. With the addition of a cheap DIY oscilloscope which requires a 9V supply, this project became more and more important.
With the start of my sem break, this long overdue project finally got the chance to be completed.


Another shot at the completed project exterior.


The interior.


Okay, time for some explaination. This “power supply” is basically just a buck converter, I am using a cheap one from China, using MP1584EN as the switching IC.
My plan was to change the SMD potentiometer, to a bigger one which can be turned by hand. (I was frustrated by the need of a screwdriver just to change the voltage level.

The input is taken from a laptop adapter, which I have one laying around.  So, it is a 19-21V to maybe 0.8V-18V supply with a maximum of 3A load ( that’s what the datasheet and seller claims, I would not use it for more than 2A personally. )


The potentiometer solder pads were quite small and were ruined when I desoldered the pot. Heck I even spoil the pot! Then I put a 10K potentiometer initailly, found out that my input would not rise over 2V. I figured my resistance was too low for the feedback path. I then change the pot to a 100K pot. Better, but the voltage stopped at 10V. Can be used, but I wasn’t satisfied. I found that the resistor value is different for 2 batches of boards. Refer to the following photos.


This is from the old batch, green colour board. Now If we zoom in to the resistor,


It’s 322, as in 3.2K ohm.


The new one, (as in the one I used), blue board, has a 822 SMD resistor, 8.2K ohm. The potentiometer forms a potential divider with the resistor to produce a feedback to the IC. The IC requires 0.8V at the feedback. 100K is simply too small for me to generate up to 18V.

Thus, I hacked the board, again. I have some 10K SMD resistors around. I simply soldered them on top of each other, to reduce the resistance. SO in the end, it’s 8.2K//10K//10K = <5K ohm!
And that worked! Circuit theory rocks! Sorry I just have to bask in my glory for a little while.
Now, I can move on the next project, which is still undecided.

 See you next time!

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Labels: Arduino, Electronics

Arduino Uninterruptible Power Supply (UPS)

Recently a friend of mine asked me to design a simple Uninterruptible Power Supply for Arduino using some handphone battery ( Li-ion) and handphone charger.

I decided to use a TP4056 charger board to charge the battery, while using a P-MOSFET to control when will the battery provide power to a 5V Step Up Converter.



The schematic shows the 5V from a handphone USB charger feeding a 5V Boost Converter, which powers an Arduino Uno. The 5V will also charge the Li-Ion via TP4056 board. If the USB Supply is gone, the P-MOSFET will be switched on and the Li-Ion battery can power the Boost Converter.

( on second thought, now I am thinking about the usefulness of the P-MOS. I was thinking of switching the battery on and off but now I think it serves no purpose... LOL)

Anyway, the 2 diodes are 1N5158 , I forgot to change it on the schematic. I think the P-MOS can be eliminated because the 5V from the USB would have prevented the battery from supplying power anyway.



This is my end result on a perf board. My friend says that it is working fine, at least until now. (I have no confidence in my design).

Cheers!

p/s :for the improved design, go to http://chanskingdom.blogspot.my/2016/10/arduino-uninterruptible-power-supply.html

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Labels: Arduino

Fix a 8Gb Pen Drive

Never in my mind I thought that I would find a FAKE pendrive in my house. Here I am, holding one. My mom bought this like years ago and it broke just weeks after it was purchased. I knew something was wrong but never had the time to dig deeper. (Click on the picture for the actual size photo)

Our Main Guest today!

The gut of the flash drive. I even opened the casing to see the controller code. It was futile.

Today, I was searching for an answer for this. I thought it was just a simple corrupted sector or memory. Googled whole day, tried all sorts of formatting tools, from Windows built-in formatting tool to the HP format tool, but all were unable to complete the formatting. The Windows Formatting says that the disk drive is "Write-Protected", and changing the registry key of HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies to 0 did not work at all.The Low Level Format Tool returned Device I/O Error  for Format Error Occurred at Offset 0 and so on for all 8Gb of memory location.

Then, I stumbled across the Chip Genius tool. It shows the chip and vendor information.

This is after I have fixed the drive. Before this it showed  something like "山寨黑盘" which means it might be a fake drive from China. Anyway, nothing can be worse, perhaps I can at least salvage what is left of it.

Google showed me AlcorMP, a software they used to program the controller of the USB disk before selling the disks. This is how they "fake" the memory size of the disk. ( do correct me if I am wrong, I'm not so sure about this myself)

Tried the first one, failed. Second one, failed as well. Turned out I need to find the one which will work with my Firmware. The info is listed as "F/W EF66" as shown in the picture.

Google pointed me to http://flashboot.ru/files/file/53/ , where the translation for the comments showed promising result for my firmware. But before that, I need to make sure AlcorMP recognise my disk.


Following the steps from Formating USB with Manufacturer Tool - USB Drive Format Utilities - reboot.pro , I added my VID and PID for IgnoreVIDPID and VIDPID , which in my particular disk is 00117788 into AlcorMP.ini file.

Run AlcorMP.exe as ADMIN ( this is very important as I could not load the driver without admin access) and this will pop up.


Click Start and it will start to scan for bad sectors and restore the disk to its default value.

Mine actually became 1.4GB only after the process.( verified using H2testw)
I hope this post will be useful for those who struggled to fix a broken or "possible Fake" flash drive. Until the next post, have a good day. :)

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Labels: Life

Introduction to Papercraft

I am taking a English Language course in USM, LSP404. The course requires an Individual Oral Presentation as an assessment. So, I took the opportunity to introduce papercraft, a wonderful hobby rarely known to Malaysians to my friends and lecturer.

I made a Pikachu from Paperpokes ( partly because I wanted to build something. It has been like one year since I used my cutting mat and pen knife) and documented some of the building processes in the slides. The slides should give a good introduction to those who want to start on this hobby but are clueless about the process.

Feel free to leave a comment or email me in case you have any questions.

I hope you enjoy the slides and keep papercrafting!

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Labels: Papercraft

Akatsuki Gundam from Dragon Momoko

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Labels: Akatsuki Gundam, Dragon Momoko, Gundam

Gundam Exia by Toscraft

Hello guys. My bad, been procrastinating again and again. Today, it’s the final day of my mid-semester break, and I finally have the ‘mood’ to type again. Same thing repeated, a lot had been done, but no time to blog, haha. While my Sword Impulse is put away, ( the ink quality is… terrible. The red is so washed out now I am hesitating to reprint the templates, but when I look back at the head, it’s quite good… Any idea?   ) I built another gundam. This time, it’s GN-001 Gundam Exia. This wonderful model is designed and distributed for free by Toscraft.

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Labels: Gundam Exia, Papercraft

Happy White Day

Sorry for not posting since January I think? A lot has happened but I just could not squeeze the time (and mood) to blog. Thinking about editing and posting makes me wanna procrastinate everything! If anyone has any ideas on how to overcome this situation, please kindly let me know.

Anyway, I made this on White Day. as requested by my friend. This is just  a guideline for him to follow, I hope his girlfriend will appreciate it! It was not too hard, but not easy too!

Happy White Day once again!

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Labels: Papercraft

Head is Finished!

Hey guys! Finally, the head is finished!
Can't stop looking at the 'handsome' face of Sword Impulse LOL.

Anyway, this is to illustrate the amount of papers required by this model.


And look at the thickness of the papers...

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Labels: Papercraft, Sword Impulse Gundam

Sword Impulse Gundam Papercraft

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Labels: Papercraft, Sword Impulse Gundam

Projects in USM

Twiss Programme

Last week was one busy week. My weekend was packed with activities and programmes!.
One of them was TWISS Programme. I don't have a clue what is the full name for TWISS ( I think TWISS is a short form, right? ), but it was meant to introduce to us, USM School of Electrical and Electronic First Year Student , the concept of Student Centred Study.


It was organised in Friday and Saturday, using almost two days, and we were required to build an electrical car!

I was totally stumped by this project as we don't even know how to use a breadboard to test our circuit, not to say building a complete circuit! Well, they provided us with some short training session... Personally, I feel that the training session is too short, I had to take out all the components even before I completed my circuit. But then, this is the first time they organised such programme... So, keep up the good work!

Anyway, this is my complete circuit board done by my team. We did it quite fast, way ahead of other groups and most importantly, it works!


But then, nothing is certain in this world.

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Labels: Life, USM

USM-Universiti Sains Malaysia

Wow, it has been quite a long time since the last time! Life is truly hectic here, with assignments, quizzes, and activities flying towards you, you’ll have to pick up some "manoeuvring” skill to avoid accidents with all those stuffs.

To cut it short, I am now taking Electrical Engineering in Universiti Sains Malaysia. One thing to note that I am now in the Engineering Campus, not the Main Campus. Feeling surprised? USM has 3 campuses, another one is Health Campus in Kelantan.

Below are some of the photos around USM, courtesy of my friend’s handphone. My HTC Wildfire S has a weak camera, unfortunately.

View from my hostel room.




Random shot of the sky I guess?

Pusat Pembangunan Siswa, or PUMA. Basically all the students’ activities are held here.

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Labels: Life, USM

SD Wing Zero Custom- Wings, Rifles and Completed!

When you read this post, I am no longer in my own house.
I am on my way to USM!

And Wing Zero Custom is finished just two days before my departure

Wings

Okay, the wings are completed, and they are gorgeous! Of course, it is still unable to balance itself but I am fine with that.




Did not expect that GunPla beam saber can fit inside the palm. It is HG Infinite Justice’s. Looks good eh?

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Labels: Papercraft, Pokemon, SD Wing Zero Custom

Charmander V2

A short post about Charmander V2, which I made before Wing Zero Custom is finished. Gave it to my cousin as a gift.

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Labels: Charmander, Papercraft, Pokemon

SD Wing Zero Custom- Wings

What is the first impression in your mind when you heard the name ‘ Wing Zero Custom Gundam’?
For me, of course it’s the WINGS!

Nothing can beat the beauty of wings, and in this case, the difficulty as well.

These are the first part of the smaller wings at the back.




Finished first part.

With other larger parts.

Finished ‘ smaller’ wing. Somehow, I love this photo very much. The lines actually enhance the shape of the wings. At first, I thought the lines are disturbing because the parts look very dirty with the lines on. Well, this shot proves me wrong.


The much more complicated side wing. I call it the ‘large’ wing ,.

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Labels: Papercraft, SD Wing Zero Custom