I have been working on the Jukebox project while code for the Enstall project client is being worked on. I had to find a music playing library that would be fairly portable. While C# with mono can easily transport Windows, Linux, and Mac, I could not find a audio library that did that. I wanted to be able to decode mp3 files as well as other compressed audio formats.
One option I had was converting all the audio files to WAV files or OGG, but these files are significantly bigger; along with, going from a lossy format to those would be a waste of resources. After looking at around 6 audio solutions I went with the easiest. To the horrors of many, and the silent screams of some, I detect your OS, then unpack that OS version of VLC. Once unpacked it starts with only a Telnet interface; with this interface, another thread logs in and controls VLC. So I have a standardized communications language, and I don’t have to handling decoding, audio cards, audio channel selecting, ect.
If you have not used this before it is built for a program to control it, there are controls such as “get_playtime”. You get a nice computer readout from that. One downside is that there are slight differences from windows to Mac to Linux, but those are easily accounted for.
If anyone has another easier solution drop it in the comments but for cross compatibility this seems to be working well.
Author: danberk
News
I have started using the twitter feed for the site more, I am posting random news stories and articles I find interesting. http://www.twitter.com/buildingtents
Enstall Project
I am working on a project called Enstall with a partner for RCOS @ RPI, it’s available at enstall.wordpress.com, the goal is to make a package management system. One may say “but Dan there are like 10 available and one or two are already open source…” That is true but most of them are aimed at IT personel, and controlling all the computers in a corporation, this is just for a student to install and get software from their school on their PERSONAL computer. That’s the dream.
6to4 Card Cleaner Github!
Here it is! The source code (all be it not great) for 6to4 card cleaner up on github. This program has become less useful recently because my school recently implemented IPv6 across the network, and that has seemed to fixed the problem, along with new images. Anyway have fun with it, build it out, add to it…
PHP/JS and C# Encryption
Here is some code from a project I have been working on and then shelved. A C# (mono) project creates a RSA public/private key pair, then gives the public side to a MySQL database. The private side is saved to the hard drive for later. Then PHP dynamically adds the currently active key public portion into javascript, which encrypts the users input, and saves it to MySQL. Then the C# application can get the keys it has saved in a good place, and decrypt the data in the database. Benefits of this include the web data is secured from the client to the server, and even if somehow someone steals your database off your webserver, they dont have the encryption keys to take it away. This system also has a way to deactivate a old key and move to a new one, if more code was put into it someone could revoke a old key and migrate all the data using it to a new key, but that wasn’t implemented. I thought this would be a cool project and I learned a lot about RSA public private keys, a lot of languages handle the keys differently; some take it in hex, some do it differently, some call the parts one thing, some call them other names. The javascript portion is based mostly off this library (link). JQuery is used for ease.
Feel free to give feed back or use this, open source fun.
Update
Hello Internet, I am back at school; along with working on some new and exciting things. https://github.com/daberkow is going to be my new GitHub place where I put up fun and exciting code, as well as add older things I have worked on and not released code for. Below I will list a couple projects and their state:
Javascript/C# SSL: I am slowly working on putting up open source code of the Javascript/C# SSL code
6to4 Card Cleaner: There was a error in the server side version library, that was fixed and clients should be able to update to newest version of 1.63
Duplicate Image Thing: I havent done much with this, I will be adding it to github for anyway to play with
New Project! Jukebox: I am working on a Jukebox from scratch, it will be based on raspberrypi.org computer. Designed as follows using EL lighting.
Update
Version 1.61 of 6to4 Cleaner is out, but apparently it has a bug in it, so 1.62 will be out soon. Also I have been working on a lot of code internal to my job so not much I can post. I worked on a system that combines a .Net application, with javascript and PHP to allow a website to encrypt data and securely store it in a database so that only the back end .Net application can decrypt it. I will take out that junk of the code and post it soon, if anyone wants to play with it.
I recently have got CCNA certified so that has been eating a good amount of my time.
Duplicate Download Gallery v.01
I was going through all my photos the other day when I realized there were a lot of duplicates, I wanted to find a easy program that could find these. After some searching, I found a bunch of programs that worked, yet cost a good amount, and I didn’t see any that had the feature set I was looking for; including a list of the files which I could save, a method to move the duplicates to another folder, and customization. Along with most importantly I wanted a FREE duplicate file finder, not expensive one that did a simple job. So I made my own. This is version v0.01, the main function works well, the main interface is meh, but it works. More updates and features to come, but for one days work its good. Also I am going to be opening up some software in the future, including this one when its closer to completion. If you have any features you think of leave a comment, I was thinking about adding a preview for photos, music and maybe video. Saving, loading logs, delete all but one copy of file, not bad interface…
Download:
https://github.com/daberkow/daberkow.github.io/tree/master/DDG
Creating a Radio Part 3 – Computer and Software
This is article 3 of the Building a Radio Series, before we looked at the general project overview, along with how the Arduino was hooked up. Now we will be looking at the PC hardware along with the code being used to do all the music.
I was afraid that this project world have one critical weakness, that the pc running the show would end up taking a while to start up; making the whole thing slow and by the time it came up you didn’t want to use it. I ended up getting Intel D510MO, but any computer that runs Windows would do. To save myself from having to write my own music player/interface over a music player this project relied on Windows Media Player using C#. This made it really quick and easy to build the DJ software. Mine had 1GB of ram, and an 8GB Kingston SSD (model S100S2/8G), and a Kingston 19-in-1 media card reader. There was a USB hub in there so it could be just 1 USB cable instead of 2.
I have a MSDN account so I was able to get Windows XP really easily, it theoretically could have been Windows 2000 or newer, but I was worried about drivers for Windows 2000, so I went with the next lightest OS. I went through and cleaned it out a lot, disabling parts of Windows I didn’t need; there are a lot of guides online to speed up Windows XP. Just make sure Windows Media Player is on whatever OS you use, I was developing on Windows 7 Enterprise and it didn’t have it. I freaked out will I realized I just had to go to Add/Remove Programs -> Windows Components and add it. As mentioned in the earlier article, the speaker in the unit went to a USB sound card. The USB sound card ended up being a good amount louder than the built-in sound card. The code adjusts the Media Player sound volume, not Windows volume.
The software is commented, so if you are interested in depth, you may want to scroll down and download that. But a quick overview, the program scans for removable cards, and then it scans them for the folder structure it uses. 
Then if there is only one card that meets these criteria mounts it as its source. Then it goes to the com port that is saved in a settings file in the same location of the program. If the interface is used to change the interface it should change it in the settings file. One problem is I was under the clock in this project, thus my usual extensive testing wasn’t done; it is possible bugs exist, but I think I found all the big ones.
A thread is spawned off to get input from the knobs, this is a separate thread so it can change settings while other things are going on. It reads the input from the Arduino, and makes adjustments when needed. In the boot process it gets the channel number so that the radio knows where to build a playlist out of. It gets the songs, mixes them up then adds them to a list, it then grabs all the “spots” mixes them up and puts one in every 4 songs. After all this 30 minutes of static is put in; in theory once that starts there is a 30 minute timer to shutdown.
That is the basic view of the software; the code is available below, with comment that anyone can have fun with. Any questions can be emailed and/or posted on the blog. This wraps up the Building a Radio series, unless I think of anything else to put up about it. If anyone has a idea of another project shoot me a email.
(LINKS)
Creating a Radio Part 2 – Arduino & Wiring
This is article 2 of the series on building a Radio. A key part of the project is the interface; I wanted to keep 100% of the original radios look and feel; that meant somehow I needed to use the knobs in the front along with the spinning the dial. The solution I came up with was to use an Arduino microcontroller, more specifically the Arduino Uno, to handle all the hardware interactions. This article will look at how it was hooked up, along with the code used for it. For the purposes of this article I will not go into too much detail about the parts, and allow the reader to research where needed.
In total there are 5 “devices” hooked up to the Arduino, the first three of these were the knobs. The volume knob, an original knob that came with the unit, feeds the Arduino a number, 0-1023 using a 5 Volt line, then that was mapped to a number between 0-100 to make life easy. The leftmost knob goes between AM/FM/AMC, and on my unit I could never get a stable reading out of it to feed the Arduino, so this knob is actually disabled on my final product. I could have replaced that knob with another, but I felt the project was great without that, along with it would have added a lot of work and stations to make. The center knob is a 10kΩ potentiometer I bought from makershed.com, they seemed to have a size that fit well; I had to drill down the inside of the plastic knob, but that’s how these things go. The two wires I got from the potentiometers each went into their own analog pin, I used 5 for the volume knob and 2 for the station, but this is completely arbitrary.
At this point I should mention that devices like the servo came with a little header on their wires. I took that piece on, and soldered a good wired onto the end to put in the Arduino. The wire the servo came with was thin and didn’t go in a pin well. Moreover all the parts needed power, so I got a tiny bread board from THE SHACK, took over one two row part of it that had double sided tape and put it in the radio. Then whenever I needed 5 volts, I could just use another pin in the bread board. You can see this in the photo below.
The next device to hook into the microcontroller was the servo, now as I said in the last article where I went over me tearing parts out of the original unit; the station knob was done with a string and a sensor and awfulness. Thus, I am using a servo instead; the code gets the input from the station knob, and then adjusts the servo to that mapped value. I got a HexTronik HXT900 Micro Servo 9g/1.6kg off Amazon for cheap; it works well, is tiny, and did everything the project needed; yet, it is fairly loud, so if that is important to you (when the station changes you hear it) then you may want another one. I put the servo in Pin 9 on my Arduino.
The last little device that was hooked up just for fun was a little yellow LED; my radio had a burnt out bulb next to the dial, so I replaced that with a LED. The 13 pin on the Arduino Uno already has a resister on it for a LED so I just put it in there.
The code is fairly simple and straight forward, it reads all the knobs, adjusts the dial when needed, and then sends all its readings over USB to the PC doing the music playback. The baud rate is set for 9600. The one little problem the Arduino code gave me that I didn’t foresee was I needed a set “packet” length to go to the pc, thus when the PC reads the line it knows if it got the whole data set or not reliably. To do this I have a set pattern that the data is fit into. It goes | then whatever the volume is | channel number | and then enough dashes to fill up 10 characters. So an example could be |100|5|— . I thought it was a fun and interesting little quirk.
The system waits 200ms, to let the values change and stabilize if they want, then does it all again. I am used to desktop programming where 100% CPU is bad, so I treated this similarly by habit, but you could speed it up if you wanted. The code is going to be in here to follow (its pde, but rename to TXT works too), along with a picture of the wiring (though some wiring may have changed in final product, old picture).
One part I have yet to mention that is a critical component is the speaker, I used the speaker that came with the unit. I cut the wire from the original circuit, then got a 3.5mm stereo jack from THE SHACK and soldered the wires onto that after making sure that I got positive and negative in the write positions. I can’t guarantee this will work with all radios but that plug was able to go right into a USB audio card I used.
Feel free to email or post with questions. The next part will be the PC and the software running all of this.
https://github.com/daberkow/RadioManager/blob/master/radio_controller.pde
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