NYC Subway train doors are a real danger


Lately I’ve been commuting by NYC subway to work.  It’s been a pain figuratively speaking as well as literally.

This Friday morning, it was less crowded on the train station than on a regular weekday and people calmly were entering arrived train. I politely let people in front of me go and went in last. All of the sudden I felt like I blacked out for a millisecond as I felt this unexpected blow on the side of my head. It felt like being slammed into a brick wall and I almost fell down. Took me a second to realize that I was just hit by unexpectedly slammed train doors.

Don’t let the rubber edge and elevator like appearance fool you. These freaking human traps pack a heavy punch and close extremely fast. I’ve caught few blows to my shoulders before, it really hurts like a mother.  Unlike elevator doors, subway trains will also not open when obstacle is encountered. They will alert train operator who must re-open them remotely.

Another thing I noticed (just like this morning) that train operators are always in rush to close doors and sometimes don’t even check if all people entered the train.  I can kind of understand when this is happening during rush hours when people can no longer fit into the train car, but it was not the case this morning.

Something needs to be done! I can’t be the only one who feels this way. What would happen if instead of me it was a mother carrying infant. Doors can easily crush baby’s scull.  Why is there so much force in the closing mechanism?  I wrote a letter to MTA, if you feel the same way please write one as well.


Geiger counter experiment with 1B22 tube


Recently I bought an awesome Geiger Counter on ebay: restored Ludlum Model 3 with 44-9 pancake probe.  I had fun with it testing around the house but didn’t see anything spectacular.   I had a piece of “uraninite” ore I got from eBay a while ago and it sure can detecte elevated radiation levels coming from it.

Few days ago however I stumbled upon a video that was talking about an old vacuum tube 1B22. Apparently it contains Radium 226 and it’s among strongest legal radiation sources you can find. To my surprise I had no problem locating it online and it only cost $15 plus shipping. So I ordered one and it just arrived in the mail. Keep reading, pictures are after the break! 🙂

Read the rest of this entry »


Introducing Xronos Mega!

There’s something that I’ve been working on besides Xronos Alarm Clock for the past 6 months.

Read more here


Geek week is not what I expected…

This week is a “Geek Week” on Youtube.   I consider myself somewhat a geek, since I love technology and spend a lot of time messing with computer, photography, electronic circuits, etc.

But watching few intro videos on Youtube I was a little bit shocked to discovered that it’s just basically some Star Wars/Anime/Xbox playing fanboys… Boy did I have “geek” and “nerd” definition all wrong?  Always thought Geek=intelligent/inventive, not Geek=Fanboy of a fiction story… 🙁


Controlling Roomba 550 series w/ Arduino


I had my Roomba 551 for a long time (over 5 years). This model was only sold in Costco, but it’s basically a 550 model, slightly repackaged.  It was a somewhat lousy vacuum cleaner, as it would require preparing room for it by blocking access to shaggy carpet where it would get stuck and removing all cat toys on which it would usually choke. So it’s been collecting dust for a a while (passively). At some point few years ago before I learned about Arduino I’ve got a “Hacking Roomba” book and tried to … well hack my roomba. I wanted to turn it into a mobile camera. I bought a RooStick which was DIN8 to USB interface (no longer sold) which allowed to connect roomba to computer. I even built my own roomba interface cable from old keyboard cable. However it got me nowhere at the time.

Recently having some success with Arduino, I wanted to build a moving camera platform to watch over my cats while I’m on vacation. Plan was to use Roomba as mobile platform and power supply. Since it can supply over 16 volts, I should be able to power WiFi IP cam, Arduino and small wireless router.  Router would be used to control Arduino via internet. Because I already had ethernet shield and didn’t want to spend lots of money for WiFi shield I found this really cheap and small router TL-WR703n. With custom OpenWRT firmware it can serve as a bridge, but also because it has USB port I can connect WebCam to it (althought since I’ll be using motorized IP cam, it’s not really required).

But firs thing I need to do is to learn how to control Roomba with Arduino.

Read the rest of this entry »


Xronos clock is now available for sale!!!

My Etsy shop is now open, and I have 3 clocks for sale!  Two with yellow middle button, and one with orange.  New picture are here too! Don’t forget to check out official site I’ve added source code and schematics!


24-bit 192 kHz music distribution makes no sense?

Stumbled upon an interesting in depth (very long)  article about 24/192 music downloads. Lot of good information about audio encoding, human hearing range, etc.

Even better, check out this Video Presentation about audio encoding. Nice site overall, gotta do some digging there 🙂



Rapid BootLoader Shield


What is it?

Purpose of the Rapid BootLoader Shield (or RBS) is to quickly program 40 pin ATMega microprocessors (currently supported ATMega644p and ATMega1284p). It’s a no frills open source shield that plugs into Arduino Uno, and using Arduino as ISP allows to quickly burn Sanguino (or other) bootloaders quickly thanks to the ZIF (Zero Insertion Force) socket.  It also has FTDI interface so you can program your sketch. No need to remove it from Arduino in the process.
It’s very useful if you need to program many chips in a hurry without much of an effort.  I’ll provide all schematics and instructions below so you can build one.


Not many to speak off 🙂 It has 40-pin ZIF socket, FTDI and ISP headers and 3 indicator LEDs (Green,Red and Blue) that will indicate you process of loading firmware/bootloader.

How to use it?

Read the rest of this entry »


Bytesize update: Xronos code tweak, new clock concept

Today I made another small tweak to the Xronos code. When changing Alarm hours/minutes with each button press change would be written to EEPROM. This would unnecessary wear out EEPROM which is rated for 100,000 write cycles.  So I made small change to only write settings for alarm hh:mm upon exit from menu system and only if hh:mm were changed.

I’m also actively ordering parts to make a 15 piece batch of Xronos Clocks for sale. That’s probably too many to see if anyone buys it, but I had to order parts in bulk to get lower price… Enclosures have been ordered from Pololu, and electronic parts from various vendors. There was a set back with TaydaElectronis. I ordered some important parts (such as temperature sensors and RTC chips) but got lost in the mail, so after a month they gave me refund and I placed another order. Hopefully I will receive that one and soon.

Also I started working on new version of Xronos Clock this time on a bigger scale and for the wall mounting.  It will have four 24×16 green LED displays, remote control and RF module to get temperature from outside.  Already working on small enclosure for outside temperature sensor (based on moteino)


Xronos Update: New PCB is here! More pics


PCBs from iTead finally arrived!  It took 12 business days from ordering to receiving them, not too bad!  Strangely there was no text (silkscreen) on the back of the boards, which is not a big deal, but something I need to figure out.  This is first time I got PCBs made from Gerber files, so it’s possible I did something wrong.

I immediately started assembling one to see if everything works, and it does! 🙂  Took me about 40 minutes to solder everything, but I’m sure I can do it a lot faster (15 minutes maybe?).


Removed old board from enclosure, plugged in new one, and bingo everything works!