I decided on Saturday that I'd try my hand at building a setup with the Arduino to detect sound. I found the perfect schematic online here from the guys over at SparkFun.com. They have a really nice breakout board for an Electret Microphone but it's ~$8.00 and I already had the stuff on hand to build my own. I think I'll still pick one of theirs up at some point, just to have around. It's quality built and tiny. I've attached the Schematic and the code with additional high-res pictures below for anyone more interested. I used an OpAmp to increase the voltage and had the code check for a threshold. Once the threshold had been exceeded, it would light up the red LED. The end result looks very similar to one of the old-school VU meters. You can adjust the gain on the amp by increasing the R5 resistor. This would make an excellent sound detector or even could be hooked up to a small speaker, it's a simplistic mono-amplifier after all...
Being a .Net developer, I figured I needed to know how to get my applications to talk to the Ardunio board via the USB serial port. Took a few hours to get the Ardunio code working, but here is the final results.
I setup a simple VS2008 C# project (you'll need to modify to compile with VS2005) to turn a LED on and off by clicking a button on the form. You'll need to change the hard-coded COM port to the correct one for your setup and hook up the LED (don't forget your resistor) to the digial PIN 12 on the Ardunio board.
- A few things to note:
- I'm using a fixed char command "INLENGTH" which will need to be updated if you wish to increase the command char length.
- I've used # to pad the command when I don't have a 6 char command.
- LED must be on digital PIN 12 (you can change this in the code of course).
- COM port is hard-coded in the .Net code for my setup, change to correct COM port on our computer.
I decide to stop by Radio Shack and pick up a seven segment LED (RHDP) so I could learn to use it with my Arduino board. I had actually ordered a few from Jameco but I had a couple of hours to kill today so I decided to feed my impulse. The cool thing about these displays is that they are really easy to use. You can see in the pictures there are lots of wires, it basically takes 1 digital output per segment and a common ground to run it (I didn't use the decimal point), but really the coding was super simple. Ignore all those resistors on the picture below, I didn't have a 68ohm resistors so I had to improvise with some lower ohm resistors put in series. This is a very satisfying project and only took me about 45mins from start to finish, highly recommended for those new to the Arduino board... I've included a ZIP file with the code and a few hi-res pictures for anyone instrested.
So a few months back I decided to get my act together and start realoding my own ammo. Finding reasonably priced accurate ammo is too rare these days. This is my setup before the presses were put on! My father-in-law hooked me up with the sweet table (solid maple table)! No reloading setup would be complete without the classic Gadsden flag!
I'll update everyone on my progress as I find supplies! It's tough to get primers these days!
If you haven't seen this thing yet, you gotta check it out. Check out the video, this is for real...
I ran across this article while shopping at SparkFun.com. They outline some very good tips for eliminating quality issues with the boards you submit to the fab houses. If you use Eagle to build your boards, I strongly suggest you utilize their DRC and CAM files to get yourself started in the right direction. These guys have added so much to the community it's amazing.