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Fix a fried Asus RT-N16

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Fix a fried Asus RT-N16

A few weeks ago we had some power fluctuations that resulted in the power flickering on and off a handful of times before going out completely. Every time this happens, I hold my breath right after the power comes back on and hope that none of my beloved electronics are fried; but this time, I wasn’t so lucky. My Asus RT-N16 router was toast.

Symptoms: When I plugged the power adapter into the router, the power light came on for a few seconds. Shortly afterwards I would hear a slight “click” and the device would just power down.

This definitely sounded like a power issue, so I wasn’t hopeful. But knowing that my warranty had long expired, I was definitely going to peel it open and check out the situation. Before I got the screw drivers and soldering iron out, I plugged in the wall wart and did a quick voltage test to ensure that wasn’t the culprit. 12.56V output from this 12V 1.25A power adapter was definitely within spec.

The RT-N16 case is a simple assembly; remove the 4 sticky rubber feet to uncover 4 philips-head screws. After removing the screws, the top pops right off with ease. Upon inspecting the circuitry, I immediately noticed a 680uF capacitor that had crowned a bit. I de-soldered this  capacitor and scrounged around until I found a 480uF capacitor (close enough). I know it’s a major pain to solder through-hole components into vias that have already been used, so I just soldered a couple of wires to the bottom of the board and soldered my new capacitor to the other end of the wires. A bit of masking tape for mounting (couldn’t find my hot glue gun), and we were back in business.

Hopefully this will encourage a few people out there to break the warranty seal and poke around for themselves. I’m sure there are tons devices out there that have been thrown away and replaced when the fix was a $0.5 capacitor and 15 minutes of time.

Bad capacitor in Asus RT-N16 Bad capacitor in Asus RT-N16 Asus RT-N16 capacitor replaced


Hangmanduino Update

I tried compiling Hangmanduino (see original post here) again using v 0021 of the Arduino IDE and found out quickly that things had changed. So I began troubleshooting and found that the WString library I was using was obsolete in the new IDE. Long story short, I was able to make a few adjustments to the code and got it up and running. Get the new code here (no need to download any additional libraries).


Arduino IDE Crashing on Windows 7 (64-bit)

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I just spent the last 3 days (on and off) troubleshooting why my Arduino IDE wouldn’t open properly on my Windows 7 64-bit machine. I thought I’d share the fix with the rest of the world as my Google searches returned nothing in the way of useful answers to my issue. For my issue, I’d click on arduino.exe and the splash screen would display, shortly afterwards, it would disappear along with the arduino.exe process that was running in the background. I had tried debugging the java launcher, that looked fine. I had checked permissions on the folder, flipped the compatability mode of the exe, you name it. In the end I needed to check the “disable visual themes” checkbox on the exe (see screenshot).

Full path to change this checkbox: C:path_to_arduinoarduino.exe > right-click >compatibility tab > check “disable visual themes”  (not a bad idea to check “Run as Administrator” while you’re in here) > OK

Hopefully this helps someone else out there as they desperately scour the interwebs for a solution to get back into the IDE.


Br-r-r-r-r-ing…It’s your Arduino

A recent comment by the009 got me thinking…I’ve been able to get Asterisk grab info about sensors connected to an ethernet-enabled Arduino, but how about the other way around? What if you could allow your Arduino to make outbound calls through your Asterisk system to make a make-shift alarm system, or over-powered doorbell? Well, wait no longer! Here’s how it works:

Asterisk: A php script lives on your Asterisk server (hosted up by apache) that, when it’s accessed, checks to make sure the client accessing it matches a pre-defined IP of your Arduino. If so, it creates a call file with the criteria that you configure to call a number of your choice and drops it in the Asterisk outgoing queue directory, triggering Asterisk to make a call. (I would highly suggest you only set this up on a server that doesn’t have port 80 open to the world!)

Arduino: The sketch code is easy…simply trigger a client connection to the Asterisk server when a button is pushed, motion sensor tripped, or ultra sonic range finder measures a particular distance (that part is up to you). As long as the Arduino’s IP matches the allowed IP configured in the php script, your phone should ring!

Make it happen:

  1. To get started, download the code and extract the files.
  2. Copy arduino-outboundcall.php into your web directory on your asterisk server.
  3. Next, add the lines from extensions_custom.conf (zip package) to /etc/asterisk/extensions_custom.conf
  4. Edit the variables at the top of arduino-outboundcall.php to match your configuration.
  5. Upload the sketch to your arduino, customizing to your configuration (of course!).
  6. Adapt it to your project!

Feel free to edit and manipulate this script to fit your needs, I just ask that you add a comment to this page explaining how you used it. Videos / pictures are always welcomed as well!

Bent SK-1

Bent SK-1

I wanted to share my nearly-completed SK-1 project. It still needs a back panel and some finishing touches, but it sounds amazing. I can easily get lost for a couple of hours just jamming on this little guy. It features an 18-point bend patch bay, 4 ground points, patchable potentiometer, joystick, and LFO, 8 additional hard-wired bend switches, drum kill mod, soft/hard reset, and a pitch bend (mounted on keyboard) with on/off switch. Now if only I could muster up some ambition to finish it…

SK1_6 SK1_1 SK1_2 SK1_3

Glitch LFO

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Glitch LFO

I’ve been wanting to get into circuit bending for a while now, but due to a jam-packed project notebook, it has taken the back seat…until now.

Music is my passion. I’ve played various instruments throughout my life and have always loved strange and exciting sounds and instruments. That being said, I’ve decided to focus my attention on music-making instruments / bends / circuits for a while. There’s something euphoric about mixing my love for music with my love for electronics…it’s hard to explain.

Seeing as I’m still a n00b at bending, I thought it proper to start with a staple bent instrument and see what I can do…enter garage sale find #1: Casio SK-1. As I started scouring the internet for ideas of bend points, and various different things people have done with the SK-1, I came across this really handy LFO circuit based on a LM555. I had all of the components in my parts bin, so I built it and started playing. The circuit itself is nice, but when applying it to any bend points, there was something missing. One of the changes I tried out was applying a PNP transistor to the trigger, so it acts as a switch that is being turned on and off to the speed of the timer. When I applied the bend points to either end of this switch, the results were very satisfying. I decided that for my bent SK-1 it would only be right to etch a PCB, so I made a quick change to the etch template and wanted to share that with everyone. I’ve also attached a few pics and a video of me playing with my SK-1 with this “glitch LFO”. I hope someone else gets some use out of it!

Download etchable circuit drawing here.

DIY Push Potentiometer

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I’m working on a project that requires the use of two interface devices; a button and a potentiometer, but I wanted the look of the enclosure to be really clean. I was thinking about where to place the button and potentiometer, which is when I realized, it wouldn’t be too hard to make a potentiometer that could be pushed for the select function. Within an hour I had this little prototype put together. There are a few areas that need improvement, but overall, it works great! For materials, I used a spring, pot, tactile switch, and a couple of screws/bolts to hold it all together. It’s really simple to put together so I’ll let the pictures do the explaining. Feel free to post any questions in the comments section.

Oh, and thanks to Make Magazine for posting the pics from Flickr!

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Poor man’s BoArduino

Poor man’s BoArduino

I was thinking about buying a BoArduino for easier prototyping…it’s easy and cheap, but not as cheap as I am apparently. I decided to build my own instead using an old proto board, some pin headers and CAT5 cable I had laying around. It’s not nearly as pretty, but just as functional, and I don’t need to reload my code to the arduino I plan on using in “production” because I actually built it in shield format. I’m working on a prettier version, using that as a pet project for learning Eagle PCB layout. But for now, this works just fine.

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Since I started in IT, I’ve always been a scavenger of sorts. Ripping out hard drives, memory, fans, coin cell batteries…you name it. But it wasn’t until I started building electronic circuits that my scavenging tendencies really started to run rampant. There are numerous electronic goldmines all around us, that if you’re willing to open your eyes and tap into these resources, you can save yourself a bundle of money, and sometimes even open up new ideas for projects or solutions to existing projects. One my most recent discoveries of one such goldmine can be found in public facilities everywhere: the automatic paper towel dispenser.

While at work, I was walking by a garbage can and noticed one of these dispensers. It almost screamed my name as I walked by, did a double-take, and stood there for a moment to think it over. With a quick look around I made sure no one was around, I snagged it and ran for my office. I hovered over the the dismantled appliance with an evil…OK, not really…but in about 5 minutes I did have myself a nice little collection of trinkets to play with. A short list of components: 5V DC motor with matched gears, 3 or 4 different types of switches, and momentary buttons, a proximity sensor (I haven’t quite figured out how it works yet), a few LEDs, and a board chock full of diodes, resistors, and other miscellaneous components (if you take the time to de-solder).

It is my understanding that these things are very easy to find in the dumpster because they are given out by the paper towel companies whenever a company orders of product are purchased. I guess their thought is, wherever there’s a paper towel dispenser, there’s bound to be paper towels. So the more they give out, the more product is sold. Also, most maintenance people don’t even bother changing the batteries, they just grab a new one from the back closet and throw the old one in the garbage.

OK, so what’s the take-home lesson? Keep your eyes open…one man’s garbage is another man’s robot. You never know what could be salvaged out of an old answering machine, TV, network switch, radio, or even paper towel dispenser. Oh ya, and please don’t go ripping these off the wall the next time you’re in your local 7-11…they’re actually kind of handy when they work.  : )

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