Rick’s Awesome Blog

I’ve been working on this project since I woke up this morning… about 1.5 hours ago.  But I now have it successfully working with a piezo speaker as a microphone.  I had to run the speaker output through an op-amp in order to get it working, but it does work.  The only problem I’m having with it is that it only picks up noise that is RIGHT next to it.  It’s probably just the crappy speaker, but I might be able to help it out by bumping up th amplification again.  Also, I am using a quad op-amp because it’s all that I had laying around.  I’m only using one of the op-amps on the IC so I’ll have to go pick up something smaller.  I DO want to wear this eventually so size is key.

Here are some of the helpful references I have used so far:

Datasheet for the LM386N quad op-amp I’m using.

Instructable someone created about how to build a VU meter.

4/11/08 – 5:51 PM

I have completed the vu meter tie circuit – or so I believe anyway.  After purchasing two new microphones from RadioShack for this project, it turns out that one I had lying around here isn’t broken as I had originally thought.  In fact, it works WAY better than the other mics I just bought.  This one is much more sensitive to my voice.  I think I finally have the correct resistor ratios for the amplifier circuit as well.  It’s all coming along quite nicely.  I will try to post up some pictures and get schematics drawn up later, but for now I’m off to Target to hopefully purchase some stamps.  Does Target even sell stamps?

I just ordered a whole bunch of MINITEC cases from www.okw.co.uk.  They’re these little project enclosures that you can strap to your wrist.  I think I might be able to think of a few project ideas for these.  I’ll probably have something new posted up in the ideas section sometime next week.  That is if I have time between my job interview and graduation.

Also I’ve been looking into how to go about making that VU meter tie.  I’m thinking that project might move to the works in progress section real soon.  As soon as I can pick myself up an LM3914N LED driver.  This thing should be perfect for what I need.

Well, I finished the cantenna today… sort of.  I say this because it appears to be working, but not very well.  At first it didn’t work at all.  It turns out I had made a fatal mistake when I mounted the “N” connector to the can.  The signal part of the antenna was touching the actual side of the can.  This caused a short.  The actual antenna signal was shorted directly to ground.  I had to take the mount off, wrap some tape around the antenna part, and then mount it back on.

The antenna seems to be working a little bit.  I can point it off into the distance and Kismet will show the signal strength increase or decrease for the surrounding networks depending on where I point it.  The signal change is usually only about 5-8db though.  I was really hoping for a better signal.  The trick here is that it’s difficult to tell where the problem is.  It could be the way I soldered the coat hanger piece to the connector.  It could be the way the connector is mounted to the can.  It could also be the way I soldered the small coax cable to the actual network card.  There are so many places this could be wrong.  Really the only way to figure this out would be for me to get a wireless card with an external connector and hook up the cantenna to it.  My guess is that I’m losing some signal in the solder connections I made on the wireless card itself.  For now, though, I’m done with this project.  I’ll fiddle with in on my wireless for some more testing but I don’t plan on trying to make it any better right now.  There are just too many variables.  Once I get some more money I’ll but a card with an external antenna connector and get back into this.

I added a few more pages. They all involve projects I want to work on, am working on, or have worked on. I also added some pictures to the cantenna page and the LED belt page.

I just added two new sections under the “Pages” section. The first is Ideas and the second is Works in Progress. I also renamed the “projects” section to “completed projects”. I think this more effectively splits up the phases that my projects usually go through. Some never pass the Idea phase, while others get started and never get completed. This will help me to organize my projects and document how much I get completed and where I leave off.

I’ve also added some ideas I had for modding my graduation clothes. I still need some better ideas for that.

One other thing I added is the cantenna project. I’ve always wanted to build a cantenna and I finally started. I just need to buy some parts and get cracking.

Added: VU Meter tie to the “Ideas” section