Arduino!

[XCVG]

So, I got my Arduino and stuff Wednesday, and I've been playing with it ever since. This is sorta blogging I guess, but it is going to be sort of a worklog and is hacking related.

First off was assembly. The version of Arduino I got is the Freeduino SB, which is a mini-kit. That means that most of the stuff is already soldered on but you have to solder connectors and headers and things on. It was actually really easy and I think I did a good job getting the headers on . After I tested it I put together the protoboard. There are instructions on the web, but they are outdated and just plain suck . So now I have a 4-pin header with 3-pins, because it said to clip one pin off first. It turns out that part isn't even necessary. At first it didn't work because I was tired and forgot to solder the headers on all the way. I had taped them down and soldered the end pins, made them straight, and then forgot to solder the rest of the pins . My mini-breadboard is a bit messed up because I put it on wrong and pried it off. The sticky tape on the back is the only thing that holds the socket-pin thingys in too . But soon after I had an LED blinking.

After that I tried making my own programs and stuff. The Arduino programming is a simplified version of C/Java and is pretty easy to do. When I tried my button-LED program it didn't work because I forgot semicolons on the end of each line. Forgot how sensitive C was to that.

Wiring up the LCD was a little more interesting. I mostly followed Adafruit's instructions but I was tired and didn't read them fully. For example, the R/W pin needs to be tied to ground, which I forgot to do and eventually just wired up to the Arduino. Also, the datasheet for my LCD is utter garbage, with lots of useless technical information you'll never use but very little in the way of instructions . After burning out a potentionmeter (don't ask me how) I tied the "LCD Supply Voltage" line to +5V, which didn't work. Turns out that line is actually contrast control . Tried a potentiometer, fried it somehow, so I just tied it to ground and it works now. I was really happy when the example program finally worked.

Pics and more coming soon!

 

[PalmerTech]

Make sure to make a cool project with it, hardware, then sell it.

Then buy another and built it right,

 

[XCVG]

Well, been too lazy to post but finally you get a bit of an update, or at least a teaser update. I've hooked up the L293D and it works, but the breadboard is messed up. I'll build it on my full-sized breadboard and see if it works perfectly. It should, but no guarantees. The goal right now is to build a little robot with the Arduino. I've got some plans that I'll post in a bit.

 

[ShockSlayer]

whats an arduino.

Yes, I could google it, but I want YOUR definition.

SS

 

[eurddrue]

[insert ShockSlayer facepalm here]

 

[XCVG]

It's a microcontroller on a board. It had headers so you can plug things called "shields" in. I have a prototyping shield with a breadboard. Oh, and it has integrated USB-serial so you program it via USB. It also has nice software. Lastly, it's all open-source.

 

[ShockSlayer]

Coolio.

[insert ShockSlayer facepalm here]

/kick eurddrue 65089

 

[XCVG]

Bump from the dead!

Right now I'm building an Arduino robot. Here's the basic design concept:

http://xcvg.wordpress.com/files/2009/12/arduino-bota.png

It has two IR sensors on the front and two line-following sensors below. I might add some sensors to the back as well. The thing is the Arduino only has 6 ADC lines, so I can't go overboard on sensors. The IR sensors are 38KHz Panasonic units and the line sensors will actually be IR pairs, or something like that. Power will probably be supplied by a 4-cell AA pack or 9V battery. The AA pack presents a bit of a problem. The voltage is too low to step down but too high to step up, and I doubt I can use it straight, especially with alkalines (too much voltage). A single lithium cell would be perfect and better for the motors (which are rated at 3V), but not easily availible and I'm too cheap and lazy to order one. The Arduino (in my case a Freeduino SB) just plugs in the top. The gearbox is a Tamiya twin (the old style 2-speed one) driving matching Tamiya truck tires. Motor control is by an L293D, which works pretty well and is easier than using discrete transistors.

Now that we're over with the design, time to turn to the implementation:

This is the prototype, so far. Originally I was experimenting with the Arduino and a protoshield. The breadboard on the protoshield is all screwed up (probably my fault) so I ghetto-rigged the Arduino (technically a Freeduino) onto my big breadboard. The little breadboard probably wouldn't be big enough anyway. The L293D glitched and didn't work right on the old screwed up breadboard, but on this one it works perfectly and doesn't get even warm (it would sometimes get nuclear hot on the old board). I could not get 38KHz working with the Arduino. I could generate the frequency, or read the sensor, but not both, and the frequency was not very accurate. So I decided to K.I.S.S. the problem and implement a 555 circuit. The first attempt, using David Cook's circuit didn't work. So I went through my notes from electronics class and got out the diagram for the 555 LED flasher. I used different resistors (actually the ones from David Cook's circuit, but in different spots) and that one worked first try. The IR sensor now works like it should, although I have yet to test it with the Arduino. I've tested it with a voltmeter, however, and it does indeed work. Now on to how a breadboard became a robot. I was bored one evening, and I saw the breadboard and gearbox, so I decided to ghetto-rig it into a prototype. I just taped the gearbox one. There's a 9V battery under there that serves as a skid as well. Just today I fired it up for the first time (fully together, that is) and it went in a semi-straight line, which is all it's programmed to do so far. A video is hopefully coming soon.

Next, I'm going to wire up some sensor boards on perf, and write a cooler program. I'll also attempt to streamline programming using functions or something like that.