Sunday, October 21, 2007

Some more ideas

I tried changing my blinking LED code to select an LED in my array of LEDs based of the reading of the potentiometer. I hope to be able to add some LEDs to my board to be able to create 2 axis and read the values off of my old Joystick. The game port is throwing me off because of the timer capacitor thing. I'll figure it out. In the meantime I need to buy myself a multimeter so I can figure out a lot of stuff.

In the mean time, I think I'll try a vumeter. I don't see why I couldn't just plug an audio signal into a rectifier and then into an analog pin on the arduino. Of course, a line out will only put out about + or - 1V. I have some LF347 op-amps that would be easy enough to get the signal up to 5 vols.

Another thing that I want to try in the mean time is to use the op-amps to build a summer for an interrupt that triggers on 4 inputs. The arduino, it seems is limited to set interrupts on 2 pins. The real way to do this would be with another chip and have that tied to the pin that triggers an interrupt. The op-amp way would be pretty easy for as many triggers as I'd please.

And yet another thing I want to play with, is an old 4 digit switch that I pulled out of some spectrometer or something. The problem is that each digit has 4 wires making a total of 16 wires plus a rail, making a total of 17 wires. I guess the way to read all 4 digits would be to split the rail in 4, and connect the 4 rails to there own pins, then connect the 4 wires for each digit to all the other corresponding wires on the other digits. This would use in total 8 pins. I have 2 of these 4 digit switches, so 2 of these switches would only use 12 pins on the arduino. If you've seen the multiple joystick tutorial, this uses the same concept.

Tuesday, October 16, 2007

Today it begins!

So, today my Arduino arrived in the mail today. It's shiny and new. I decided to start documenting my efforts in able to raise awareness of the cool things you can do with a little i/o board.

Before I get into the fun of the Arduino, I will bore you with a little background about me. Blah blah blah. I am a senior at the Mormon school, that's right, the Mormon school, BYU. I may refer to it as the BYZoo at times. If anything, this blog will be proof that one can have fun without all the alcohol and sexy women that I know all you fellow Electrical/Computer Engineers rope in. (That is after you graduate and earn enough money to choke a donkey.) I am studying Computer Engineering, hoping that one day I might join the world of the Alumni. I have always been interested in stuff like microcontrollers and hoped to get into PICs in highschool. The cost was prohibitive. $100 for a programmer, $200 for an IDE, etc... A couple years ago I met the OpenSource community and starting using Linux on my computers. When I discovered the Arduino it was a match made... in heaven. (If my wife is reading this, you were my first match made in heaven, so don't get jealous of a PCB and a few surface mount components.)

I have been saving parts from devices I've taken apart in hopes of using them someday in cool little projects. Ideally, I wanted to use the devices in a robot that would have a video link, and be controlled by my own RF controls. So, I will be doing little projects using the Arduino that will eventually help me build a kick-A robot with which I will certainly control most of the western and parts of the eastern hemispheres.

My first project today, was a simple little LED blinker connected to a potentiometer to control the speed at which they blinked. I just modified the blink example that comes with the Arduino IDE to blink 6 LEDs back and forth at a rate read from an analog potentiometer. The hardest part was installing the Arduino IDE. I use ubuntu Linux on almost all of my computers. It took installing some packages before I could get the board to communicate. I will upload those instructions in a little bit, should anyone have similar problems.

Some of the things that I plan on doing for future projects include:

  • Connect old joystick up to the Arduino and to be able to read position, throttle, and buttons

  • Using pulse width modulation to control store bought RC car through a joystick - purpose being to give smoother controls

  • Connect RF modules (receivers and transmitters) up to Arduino boards and be able to communicate

  • Connect camera pulled from old cell phone and view video from the camera

  • Implement multiple PID control using a single Arduino

  • Create diabolical doomsday device with Arduino that will bring the city of Provo under my control. (I hope the FBI doesn't start profiling me because of this... I really won't build a doomsday device. Maybe a doomsminute device that may only stress the world for about 60 seconds.)

  • Whatever else comes to my mind...

If you are interested in any of these things, let me know and, of course, stay posted. I'll share my findings with the world and will post short clips of my projects on YouTube.