DIY Drill Press

This is an old project which I built since last year. I just want to share and add as a project log here.

As a developer from undeveloped country, my budget is very limited. So, I chose DIY style drill press.  So, I have to collect parts for my projects from old printers, scanner, etc.

This is a pilot project , built for my need to build upcoming a CNC project.  Another problem, I don’t have any power tools except a small drill gun and hand tools. After learning DIY CNC process from internet, before building a CNC, I think I should have a drill press for perpendicular drilling. So,I decided to build a drill press first.

1# collected required material for base and a cheap china made rotary tool. A bamboo kitchen plate is my favorite for base plate in such design, weight is heavy, thick and rough. A L shape supports for vertical stands. Total material cost is about 25$ 🙂 .

DIY-csDrillPress (1) DIY-csDrillPress (3)

# Started with vertical support, vertical Z axis linear slide rod from old printer.

DIY-csDrillPress (4) DIY-csDrillPress (5) DIY-csDrillPress (6)

Fixed rods with L shaped aluminium bars with wood stoppers.

DIY-csDrillPress (7)

Assembled Z axis and rails.

DIY-csDrillPress (8)

3# prepared for linear slides and Z-axis slides. Two plastics bars are used as linear slides.

DIY-csDrillPress (9) DIY-csDrillPress (10) DIY-csDrillPress (11)

4# Prepared for rotary tool mount by cutting two plastics plates.

DIY-csDrillPress (12) DIY-csDrillPress (13)

Fixed the holder plates on vertical Z bed.

DIY-csDrillPress (14)

5# Fixed rotary tool on bed by using steel hole bars and spring. I wanted to make flexible and changeable tool bed.

DIY-csDrillPress (15)

Z axis and tool is tested and installed.

DIY-csDrillPress (16)

6# After this, a handle was designed.

DIY-csDrillPress (17)

Designed and cut push down lever crowbar bars.

DIY-csDrillPress (18)

Installed both side of gantry plate.

DIY-csDrillPress (19)

Prepared for handle.

DIY-csDrillPress (20) DIY-csDrillPress (21)

7# Finally, a DIY drill-press is on my bench. Attached a iron flat rod to strengthen vertical stand.

Nothing special, just a simple, cheap and working DIY tool 😀 .

DIY-csDrillPress (22) DIY-csDrillPress (23)


By oakkar7


$10 China GSM Phone

We have seen how new Iphone shakes the market. How about low tech phones  and how much a handset cab be cheap? Last year, I saw Bunnie’s blog post about a cheap $12 Gongkai handset from Mingtong Digital Mall in Shenzhen.  Gongkai means “Open” in Chinese and it’s the term alternative of “Open Source”. Mingtong Digital Mall is one of the famous digital gadget’s malls from Shenzhen especially cheap and copy items. I wondered how these cheap handset could be sold in this low price when I saw his blog post.

I lived in Myanmar, yes a green land opened it’s door recently. The government released telecom sector and has given the two new operators, Telenor and Ooredoo. Just a clarification, some may don’t know how Myanmar telecom sector is squeezed before 2000. I bet you will wonder how much it will cost for a mobile SIM card before 2000. It was cost about $5000 (Please up your jaw, I am not kidding :D). In last decade, owning a mobile phone was a trade mark of being a “boss” in Myanmar. Most people used a public pay land lines phone booth in every sight of cites. Seem these will soon be a history. But for now, news operators are moving and it costs  about only $1.5.

Have you ever seen people queuing for a cheap SIM card?


Yesterday, one of my colleagues showed me a GSM handset with a surprised price tag, 10000 MMK.  It is about $10 (1$ = 986 MMK). I quickly checked specs and my curiosity leaded me to bought one. It is a normal low price GSM handset with basic functions. I saw many cheap China handset but non are not lower than $20. This is the cheapest handset I have ever seen. Note that Bunnie’s Gongkai Phone is $12 at China, main land but I bought my $10 phone from local retail shop from Mandalay, Myanmar. More surprising fact is that my friend told me wholesale price is >$9. If this is right, how much it will be the ground cost of these handset in it’ts origin, China!! Unbelievable. Here is my cheapo handset. It is just ordinary phone but specs are even a little higher than Bunnie’s phone come with a box, handset, a battery, charger and a hands free earpiece.

DSCN7341 DSCN7344


The spec and functions listed on the box,

  • Touch
  • FM Radio
  • Music Player
  • Video player, recorder
  • MicroSD
  • Camera
  • Bluetooth
  • Multi languages
  • 1.8″ Display
  • Dual SIM (Dual standby) , Stereo Speaker (Really, only one Speaker), Games

DSCN7342 DSCN7343


The brand is Soloking and model is T176. I quickly searched google and searched more info.

  • Platform                       : coolsand 8851
  • Operation System      : Mstar
  • Build in memory        : 32+16 Mbt
  • Frequency                    :  GSM 900/1800   optional   850/9001800/1900
  • Multi Media                 : MP3/MP4/3GP/FM Radio / Bluetooth Camera 0.3 Mega Pixels
  • Multi Function Torch : Alarm ,Calendar ,Calculator ,Audio recorder ,Video recorder
  • Flash Card Support     : T-Flash Card Max support to 8GB
  • Languages Multi language : Arabic,French,Turkish, Thai,Vietnam,Russian, English, Hindi, Indonesian, Spanish etc

I installed battery, SIM and power up the phone.



Tested basic functions call, menu, camera, FM etc. DSCN7352 DSCN7356 DSCN7359

– FM


– It supports Java.


It even include Myanmar language support. Changed and tested it but some menu were not properly show 🙂 .

DSCN7357   DSCN7358

Finally, I teared down to check how these cheapo was made.

DSCN7363 DSCN7345

Just removed 4 x small screws, everything disassembled.

DSCN7366   DSCN7374     DSCN7369 DSCN7372


Other are usual parts such as speaker, mic,  SIM holder, SD slot, small camera, FM antenna and 2 x LEDs for torch. The phone is controlled by all in one chip.  The back side Speaker housing is attached with multi-band antenna.

  • LCD, this must be a friendly 1.8″ SPI TFT, LCD  (ST7735 controller ) from hobby shop around the world. I even ordered these LCD from elecfreaks  last a few months ago.
  • There is a EMI shield which covered the chip but google infos and some partially label can able to guess  me the main chip. It is RDA8851 from RDA Microelectronics, one of chip manufacturer from China. In short, it’s all in one chip which doo everything for phone such as baseband, interface, Bluetooth, FM, camera, Flash (32Mb build in), UART, SPI, I2C etc. Here is the links to chip datasheet.
  • Firmware is Mstar from MStar Semiconductor, Taiwan . From  Wiki , MStar is often referred as “Little-M” in Chinese community, as a contrary part of the bigger company “Big-M”, MediaTek.

– The only weakness of this phone (in comparable this price) is it’s charger. I also opened and checked the charger design. It voids all of safety rules. Manufacturer should include a more safe charger with a buck. The stock charger is one of the simplest and reduced version without any protection of it’s line. The design includes 13001 NPN Epitaxial Silicon Transistor,  1 IN4001 diode rectifier, small SMPS transformer, 5V zener, 3 capacitors and some resistors, that’s all. The output voltage is about 6V.


Final thought:

– First, I don’t expect much from this phone but the price is really amazed for me. It is a bare phone without no contract and unlocked. It exported from china to Myanmar. What will be local retail price and how much it can be lower?

– The cost of the phone is the parts and production costs plus a little export costs. There will be absolutely NO licensing, copy cats fee 🙂 and seem no certification.

– Everybody talks about SAR. But I think the RDA chip can take care of this in a basic level. The package label state that SAR Head : 0.342 W/Kg(1g) and body : 0.429 W/Kg (1g).

– I know that designing a mobile phone is not that hard. I designed my own DIY mobile phone recently with a basic functions like this phone with the same LCD. Even LCD it self costs about $6.4  in some ebay retail shops. What will be the lowest bargain price of this LCD? (I believe the LCD must be the most value part in this phone. Any idea?)

– For the chip, I don’t know how much cost for this RDA chip in volume and in retail. Bunnie said that MT6250 chip from his Gongkai Phone in retail price is $2.1.

– If someone knows about these, let me know and also share your thought.

Last :

Again, it is not rocket science to build a mobile phone. This is my DIY GSM mobile phone prototype which I recently developed for fun and hobby. Some basic functions such as call, sms, GPS are done and still working for a complete prototype. But, you may not defeat China at least in quantity and cost :D. Thanks for visiting.


By oakkar7

ISEE3 Rebooted

This post is an honorable post to a group of  Citizen Scientists and Volunteers for their effort to reboot an cold world era (launched 1978) satellite which floated around the universe.

Source: NASA International Sun-Earth Explorer (ISEE-3) The International Sun-Earth Explorer (ISEE-3) launched in 1978 on a mission to study Earth’s magnetosphere. In 1983, it became ICE, the International Cometary Explorer, and was sent on a new mission to study comets Giacobini-Zinner and Halley.

Mission control team used GNURadio (opensource SDR radio software) to wake up and control the runaway bird.

And they used the huge monster disk Arecibo because this is the only dish on the planet to reach that distance so far.



A nice , simple and clean mission control room. This is different from the war room we have ever seen.

ISEE-3 Reboot Project Mission Control Team

It was 10 July 2014 early morning, I was waiting for World Cup, surfed the net and follow their twitter stream about TCM burn (the mission control team started and burned a series of thrusters). And they also feed the live telemetry data. I followed their tweet and live data stream.





This shows how a crowd funding and citizen scientists can go far. And this is the first collaboration project with public for space science.

Congratulation to all.



While World Cup was continuing its exciting show, I made some my RTL-SDR and satellite research progress. My next target was FUNCube Sat (aka) FUNcube-1 (AO73) is a complete educational single CubeSat project with the goal of enthusing and educating young people about radio, space, physics etc.


FUNcube-1 (AO-73) Satellite

There is one thing that Funcube is magnificent than others, it’s data warehouse. The earth station can receive its telemetry data and can upload this data to data warehouse by online. There is also Dashboard Application for telemetry data decoding and uploading to data warehouse.

Here is the link for those who interested.

– Funcube Handbook 

– Data Warehouse

Dsahboard Application

N4JTC wrote about RTL-SDR and Funcube  , I followed this.

This time SDR Radio V2 software was used because this software has some distinct features such as sat tracking and I liked to test it. I believe that any rtl-sdr app can do this.


OK, before world cup final match, I do this. I tuned 145.9xx MHz and saw waterfall data stream and audible beep. It is SSB data.


Then, piped audio data stream to Dashboard application. The telemetry data show up.



I already registered to Data-warehouse sites and Dashboard App automatically uploaded to warehouse site. Then, my uploaded data appeared in site. Seem I am the only one and first data provider earth station from Myanmar.



# Final thought

– Noticed some noises along with the whole spectrum and some recommend for shielding. I have to test it. Anyway, shielding an RF device is a best practice. Hree is the link for this. I will try this.

Anyway, it is happy research and hobby time.





RTL-SDR Second Attempt

After leaving my RTL-SDR for one year, last month, I had a chance to test it again. Yes, last month , World Cup 2014 began on June and ended on July. How World Cup was related to RTL-SDR testing? Due to the east and west time zone differences, local time for match schedule in my country (Myanmar) is beyond midnight. It was a chance to make, test something while waiting for the matches.

I remember an article about tracking hobby, educational satellites with rtl-sdr. Goggled and found out these articles, good to go.

Tracking NOAA Weather Satellite with RTL-SDR,

Then, checked when NOAA sats will passed my location from these satellite tracking websites.

Checked that active sats regularly pass my location before midnight. Great, that is how I my rtl-sdr was related to world cup :D.

I read article and follow instructions thoroughly. Installed required software,

  • SDR# for receiving Sats
  • VB-cable for audio piping from rtl-sdr to sound card
  • Orbiton  for tracking satellites
  •  WXtoImg for decoding the APT signal

Most of rtl dongles have more or less tuning freq error. After finished installation of all software, I calibrated freq ppm error with these instruction. It is sample, monitored local GSM freq band and  adjusted error.

1# Antenna

What I need was an external antenna for 137~145 MHz reception. I built Ground Plane antenna in an evening because this is easy to build.

Each antenna element = 51 cm, used old N type RG213 male connectors for assembly.










Finished and installed antenna.



After tuning and trials, I track and tuned NOAA-15 satellite signal successfully.


But the decoded image was noisy and not good.


2# Second Antenna (QHF)

After several attempts, I realized that a good antenna was required for better reception. So, I tried to build second DIY antenna. After a few research, I chose Quadrifilar Helix (QFH) antenna type.

Design calculation can be done here.

And here is ready made design by G0HPO.


First , collected required copper wire (12 gauge, enamel), female RG213 connectors, coax-cable , wood rod etc. Then, tried to bend, loop copper wire for helical shape.



Soldered feed point with the help of small PCB.



Loop the balun and connector.



Final assembly, also attached recycled  rain drop covers for feed and connector 😀






Hoisted the antenna, ready to go.



As expected, second attempt results ware not so bad. The receiver show more stronger signal than first antenna.



There are still noises in receptions when sat is at lower azimuth.

Some results,




# Results

– QHF antenna is better reception than Ground plane

– BUT, QHF is a lot noisy than Ground plane

– Do I need parabolic or YaGi with tracking ?? for next

# Final thought

Sure, I need LNA for next and future test. Need to find out the list for DIYable LNA.


Fun midnight modern hamming while waiting for World Cup.



RTL-SDR First Experience

Last year, I heard about cheap SDR using DVB-T USB stick. Like everybody else, I quickly found and bought one of these RTL chip base dongle from local supplier.  My dongle is this one. It is ezcap DVB-T stick, model EXTV668 ver 8.0. This stick work well with most RTL-SDR software. I tested it with SDR#, HDSDR, SDR-RADIO.COM V2.

After testing some program and tuning local FM stations, I leaved this dongle for year.

List of compatible software is here,

Most helpful resource and credited sites are;

Quick start guide,





Listening Mandalay FM 88.9 MHz…loud and clear, you’re 59 ….


GTP-USB-Lite Programmer re-flsahed as USBPICProg

I bought this programmer from local supplier a few years ago. This is a GTP-USB-lite programmer clone and beautifully build as sandwich  style.

USB-PIC_Prog (2)


USB-PIC_Prog (3)

Some drawbacks of this programmer are:

  • I noticed that this programmer don’t work with some PC/Laptop USB port for unknown reason.
  • Don’t support Windows 7
  • Not opensource,


Anyway, GTP-USB programmers are the best and DIY friendly at their age. Mostly, I used PicKit2, PICKit3 as main programmer. So, I leave this programmer in a corner of my desk for a while. Last week, I noticed a post in DP forum about hacking aka flashing this programmer.

The original blog post here.

At the last weekend, I try to flash my GTP-USB-Lite programmer with new firmware and to use new software. The procedure is very simple.

– GTP-USB-Lite and USBPICProg are very identical hardwares, USB interface, PIC18F2550, the same charge pump, same programming header’s pin.

– The difference are;

  • GTB-USB lite used 8MHz crystal and USBPICProg uses 12 MHz crystal
  • LEDs are connected at PIC pins 11,12 and 13 in USBPICProg and pins 27,28 at GTP-USB-Lite.

GTP-USB-Lite hardware circuit

USBPICProg hardware , firmware, PC software (The best thing is  all are opensource :D)

– First, to take off and flash programmer’s PIC18F2550 with boot loader and to change 12MHz crystal in circuit

USB-PIC_Prog (4)



– Download and installed PC software and install it.

– Download last firmware and  attached programmer. The PC will detect bootloader and install bootloader USB interface driver. Launch the PC programmer software and  bootloader is activated and update firmware.

– USBPICProg-0.6.0-software –> Updated Firmware

– Then, remove programmer from USB port. Connect PGC pin (RB6 , Pin No 27 of PIC18F2550) to ground to de-activated the bootloader and activated USBPICProg programmer mode. The PC USB port will detect and installed new device (USBPICProg) driver.

Before final launch, I simply cut the trace between LEDs and  RB7,RB6 (pin 27,28) and connected LED’s resistors to Pin 11,12. LED shows signal now.

USB-PIC_Prog (1)


For now, I can use reborn USBPICProg as a backup programmer. I renamed it USBPICProg because it is no more GTP-USB Lite.




Microchip Advanced Parts Selector and other handy tools (Online/Offline/Mobile vers)

I used PIC as my primary development platform for years. Selecting a right MCU and checking features while developing is a time consuming task sometimes. Last week, I noticed handy tools in Microchip website.

The first tool is Microchip Advanced Parts Selector (MAPS) tool. There is online and also offline version. I tested both quickly. Online and offline version are same interface. Great, can search, filter and compare various PIC easily.

The link :


There is also a mobile version for both Android and IOS platforms named Mobile Product Selector.  It is also handy to use with your tablet at workbench while testing something.

Android App Link:


Wait, there are also some good tools for discrete components, Analog and Interface Products Presentation – (Offline Only). This is a power point file with good linking. You can click and find right info for interface , analog peripherals and  parts like transceiver, op-amps etc..


Last one is “Product Tables”, all PIC with required info and volume pricing can be downloaded as PDF or CVS format.

Visitor Hits Raise

It was a day of last month, waked up early morning, checked my blog. Usually, I don’t check my blog daily and sometimes once per week because there are not much visitors in my tiny blog. Also I cannot update my blog for a moment. But, my eyebrows raised. There was a site’s notification show that visitors status was more than usual. I checked status report. “More than 10000 visitors in a day”. What the hell is going on. Is wordpress domain under attacked?


I checked the traffic’s source quickly. Its come from “HackADay” and also from “Lifehacker”. I noticed the source of traffics. I am a fan of these two sites. Last year, I posted about my old laptop to All in one desktop conversion. This post was appeared in these sites and also in some several sites around.


Thanks “HackADay”, “Lifehacker” and all visitors for interesting this. Yes, recycling and reusing is good for all.

There is also another reason why I still use such old PIII laptop.

First reason, I don’t need much power for both hardware and software. Mostly, I used this for microcontroller and other circuits design development. So, I used MPLABX, Pickit2, Eagle etc. These software run well in old hardware with windows XP. And some of MCU and electronics tools work well in XP, not in windows 7.

Second reason is that this laptop is versatile. It has various IO ports, serial, lpt and usb. For serial COM port, using a hardware serial port is much convenience with some hardware like JDM programmer. And the LPT port, this is great for using CNC motor driver and handy for any hardware hacking liked JTAG and raw IO access from C++ program. Yes, it is the age of USB and LPT is not included in standard PC any more. For me, LPT is still handy interface for many case. It is fast, easy to access.

Third reason is cost effective for hardware testing. As you know, PC hardware interfacing with DUT is not a safe job. Your new model PC or laptop may blow up and consuming your pockets a lot at any time. Throwing old PC is not like this. I used this oldie for several years. It’s more than it’s price.

Bus Pirate Necktie Clip Case

Last year, I got Bus Pirate kit from Dangerousprototypes as a prize for last year 7400 competition. Thanks again DP. This is now an essential tool in by bench. It is not only BP. It came with a box, LCD back pack, test probe, lots of jumpers,.. a complete kit.



After getting BP, I try to make a case as usual. Mostly, I prefer acrylic style case like my OBLS and PICKit2. DP calls it “Sick of Begie” case. This time, I found out something which was suitable for the Bus Pirate case.

BusPirate_case (1)

Yes, a necktie clip case.

BusPirate_case (2)

GOOD, BP fits inside it.

BusPirate_case (3)

First, make holes for plastic snap-in fasteners.

BusPirate_case (4)

Second, filing the edge for USB cable connector.

BusPirate_case (6)

Then, make a rectangle for probe cable. And fitted the snap-in rivets.

BusPirate_case (7)



Finally, the case for BP was finished. It took about 15 minutes.