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Resume and bio of the author Couple of articles related to my hobby - robotics
My impressions about immigration to Australia. In Russian only. Recipes for everyday problems solving
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Andrey Mikhalchuk’s Blog

Technoblog about life

Aug 16, 2014 Fixing MacBook Pro BootCamp Black Screen of Death

So one day I’ve power on Windows on a BootCamp-enabled Windows 7 MBP Retina and after booting and making bunch of happy sounds the display went blank. No matter how many times I rebooted it the display kept looking dead. The computer was obviously running. It’s easy to check by pressing caps lock – the small LED on that button changes its status it the OS is loaded. After researching the internet I found this is a very famous issue with NVidia chipset and the only cure for this is replacing the mainboard. Bummer!
When almost all hope was all but lost I surrendered and in preparation for bringing it to the Apple Genius unplugged the laptop from power and … the display came back to life. Wow! My first thought was that NVidia chipset is still dead, but with power supply unplugged the laptop simply switched to the Intel chipset. But the thing is that Intel chipset can’t support retina resolution and the screen remained at its impressive 2880×1800 resolution, meaning NVidia were well and alive.
After opening some more time with the computer I found hilariously obvious reason for this bizarre behavior …

Mar 20, 2014 How to silence a piezo buzzer in your microwave, alarm clock etc

Almost every time I buy a piece of electronics with some sort of alarm it always includes a super loud and mega annoying buzzer notifying about the end of cycle. Though tuning it off completely is an easy operation (just open the case and cut the wire) making it just not as loud is a more complicated task involving knowledge of electronics and some soldering skills. Fortunately there is a much simpler way to accomplish the task, sometimes not even requiring the device disassembly …

May 17, 2013 FPV Japan / BEVRC Cable pinout

If you don’t hear about it FPV Japan is a small device that records standard definition video from analog sources. This is an indispensable device for FPV RC pilots and the ones who want to digitize old analog video tapes. I fall into both categories, but unfortunately the video cable from my device got burned in an accidental fire that also cause my video blog RTFMS to halt for a really long time. Long sad story …

Anyways, I was repairing the cable recently and decided to pinout it since there seems to be no information in the internet about this very custom cable. So in case if you want to build your own cable here is how it is interconnected:

Aug 4, 2011 How to find out the SRAM consumption of an Arduino sketch

  • Build the sketch
  • Find /tmp/build*.tmp folder. There should be one, if you see multiple then rm -rf /tmp/build*.tmp and rebuild the sketch. Only one build folder should be in the /tmp (for simplicity
  • run avr-size /tmp/build*.tmp/[sketch_name].elf
  • sum of data and bss values if the number you’re looking for

Jun 23, 2011 Controlling RGB LED using PICAXE-08: Basics of software PWM

Driving RGB LED with PICAXE-08M

Driving RGB LED with PICAXE-08M

I’m working on a new RTFMs episode that involves packing an RGB LED and a microcontroller into a very tight space. The microcontroller I decided to use is PICAXE-08. I chose it for three reasons:
- I had one in the box
- I had no other plans for it as it appeared to be not very suitable for what I got it for (a high-altitude balloon project)
- Using it to dim RGB LED is a challenge
Read More

Jun 20, 2011 Reading ATtiny85/45/25 Internal Temperature Sensor

ATtiny85 has internal temperature sensor

ATtiny85 has internal temperature sensor

I am working on one of my projects from RTFMs video blog (check out http://rtfms.com) that requires temperature sensing in a very small packaging. Naturally my choice is ATtiny85 – an awesome little chip from AVR that besides other goods (like 6ch PWM, serial interface etc) has internal temperature sensor. So I decided to use one. That wasn’t easy, but after a few hours of digging forums and datasheets I came up with a class that does the job with quite impressive reliability and precision.
Read More

Jun 3, 2011 Choosing best high-end HT (amateur radio handheld transceiver)

Here is some information for those looking for a high-end HT. My requirements are:

  • At least dual-band (tri,quad-band is a plus), including 144 and 440 bands at minimum
  • Good wideband receiver
  • All-mode receiver
  • Convenient control
  • Weather proof
  • Ruggedly built
  • Having a lot of features, leaving a lot of space for experimentation
  • Major brand
  • Price should be “reasonable”. It’s clear that an HT with the features listed above won’t be inexpensive, but I want to avoid paying extra for features that I don’t need or paying for something I can get cheaper in a different radio.

These are very expensive requirements and only a few HTs fit them. There are three major companies that produce something that fits most of the requirements: Icom, Kenwood and Yaesu with the following models:

Icom Kenwood Yaesu
Icom IC-91A

Icom IC-91A, from $320, dualbander, upgradable to D-STAR

Icom IC-92AD

Icom IC-92AD, from $540, dualbander, suports D-STAR

Kenwood TH-F6A

Kenwood TH-F6A, from $304, legendary radio, excellent scanner, tribander, superwide receiver (0.1MHz-1.3GHz), 5W on all three bands

Kenwood TH-D72A

Kenwood TH-D72A, from $485, dualbander, has GPS and APRS support

Yaesu VX-7R

Yaesu VX-7R, from $320, quadbander, waterproof

Yaesu VX-8DR

Yaesu VX-8DR, from $410, quadbander (with limitations on 220 and 50), advanced APRS support, GPS and Bluetooth upgradeability, WIRES, tree receivers, stereo WFM

Jun 20, 2010 Fixing Wireshark’s “TCP checksum offload” error in linux

On some linux machines when you run wireshark you may notice that a lot of packets are marked as invalid (highlighted as black). The contents looks perfectly correct, but for some reason checksum is brkoen and wireshark suggestes that the reason for such unpleasant event is “TCP checksum offload”. Let’s fix it …

Jun 19, 2010 Fix: Error: register r24, r26, r28 or r30 required

I was recently compiling some Arduino code with NewSoftSerial and got hit by infamous “Error: register r24, r26, r28 or r30 required” error. NewSoftSerial is a great library and those using older avr-gcc compiler enjoy it alot. Problem is the newer gcc doesn’t like one nasty error in the code and here is how to fix it …

Jan 27, 2010 The most hacked router in the world ever. First DIYs.

I started posting instruction on how TMHRITWE was built. The first three parts are overclocking, serial interfaces and “POE”. I especially recommend reading the “POE” part as all “POE” hacks I saw before contain one mistake potentially fatal for your router.

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