Budistični nauk razlikuje dvainpetdeset stopenj duhovnega razvoja. Eno izmed stopenj imenuje zastoj, ko se človek prilepi na eno samo mesto ne more več naprej. S tvojim mečevanjem je nekaj podobnega: če nasprotnik udari po tebi in so vsi čuti zbrani na njegovem meču, tedaj si pod njegovim vplivom in nisi več gospodar lastnih gibov. Temu pravimo zastoj, ker obstaneš pripeljen na eno samo mesto.

Celoten tekst je na voljo v PDF zapisu.

So, given that passwords shouldn’t or should I say must not be saved in a way that enables anyone (even administrators) to retrieve the plaintext version of a password, we’re talking about some sort of hashing. Whether hashing algorithm it is MD5 (avoid) os SHA1 (and in order to avoid precomputed hashes of passwords (known also as rainbow tables) you should use salting techniques with hashing algorithms), the length of a calculated hash does not depend on the length of the plain text password.

So, why is the length of the password limited to 16 characters? Beats me.

Of course, I recommend developers to use bcrypt instead of SHA or MD5. Bcrypt is very slow (compared to SHA or MD5), which is a good property to have for checking passwords — you don’t want to have a super-fast hashing/crypting algorithm thus effectively preventing brute force attacks.

• Function as a regular thermostat
• Which can be controlled remotely via SMS as well:
  • to check current temperature on location
  • to set desired temperature on location
  • to switch power on or off for the oil boiler (heating furnace) and water pumps
  • to alert via SMS when the temperature drops below a defined threshold

The Netduino/Arduino boards are amazing in that they offer a high level language to control them and create your stuff. You can develop & debug with Visual Studio in case of Netduino boards using the familiar interface and software development skills. There are tons of shields (addons, plugins) available for those boards as well. I’m planning on integrating real time clock, digital temperature sensor and a cellular shield (GSM functionality) and a graphical LCD next. Baby steps.

So, how did I wire the external LED?

First, I had to learn some basics:

1. You have to limit current for the LED, otherwise it will burn
2. You have to drop the voltage, or the LED will burn

You can limit current by using resistors. I used the 5V pin on the Netduino, and LED needs only 2.5V, so I had to halve the voltage and limit current at the same time. You can do this simply by using two resistors. Smart people call this voltage divider. First, I calculated the maximum current that is allowed for the LED, and that is 20mA. Given the 5V voltage and formula V = R*I, the resistor comes out to 5V / 0.02A = 250Ω (Ohm). Given that, I now needed to lower the voltage, which in my case is simple. The formula for voltage divider is Vout = Vin * R1 / (R1 + R2). Now that I know that R1 + R2 should be 250Ω it is easy to calculate that R1 = R2 = 125 Ohm. I actually used 120Ω resistors as I didn’t have 125Ω ones.
So, the LED was lit, but I wanted to control it via software, so I needed a “switching” mechanism. I asked around used NPN transistor for that. I connected the LED output to collector of a transistor, and connected the emitor part of the transistor to ground. Now, we need to tell the transistor to “open up”. I figured I’ll just connect the digital output to base of transistor, but friendly guys on a Slovenian electronics forum suggested that I use a resistor in between. So I did.
The end result? A program, which turns the LED on whenever I press the button. The final schema looks something like this:

This image was made with Fritzing which looks like a very promising project as well.

I am by no means a gamer (don’t play, never did a lot (except for Tetris (the original one), The Incredible Machine, and maybe something else) but was fascinated by Crayon Physics Deluxe. I’ve been setting up my father’s and my sister’s computer (they’ve bought themselves an MSI multi-touch all-in-one PC AE2220M) and found an interesting application in the Windows 7 Touch Pack: Blackboard. It reminded me of The Incredible Machine, a DOS-based game in the early nineties. Refreshing the fond memories of TIM, I read the Wikipedia article about it, where I saw the game Crayon Physics Deluxe mentioned. When I saw the demo (the video recording), I downloaded a trial and bought the game. I do own a tablet, and I’m testing it on my kids tomorrow (they are not allowed to work computer otherwise).

With regards to the multi-touch all-in-one PC: it is solid built, the sound is not so great, and the keyboard is too small for my taste and feels very plastic — it is wireless, on the other hand. Otherwise, it’s quite good consireding the price (720 EUR + VAT), sporting a dual core CPU, 4GB of RAM and 640GB of hard disk space. A quality keyboard would’ve made the difference, in my opinion, since the rest of the computer feels quite solid.

Stanovanje smo vmes že prodali.

USE MASTER
GO

ALTER DATABASE moovme SET SINGLE_USER WITH ROLLBACK IMMEDIATE
ALTER DATABASE moovme COLLATE Slovenian_CI_AS
ALTER DATABASE moovme SET MULTI_USER
GO

Hope that helps anyone.