MAKE Magazine: Comments about Articles

unabox question

Intentionally there are no dimensions you can make it the size you like keeping proportions.

Autocad drawings

I downloaded the Autodesk TrueView but the link here to the files does not work. It opens a text file and not a downloadable file.

marble adding machine

I can't get the drawings to display properly on my computer. Is there another drawing format besides png?

unabox question

Download true view: http://usa.autodesk.com/adsk/servlet/pc/index?id=6703438&siteID=123112 Its freeware from autodesk that allows you to view and print dwgs. You can then print the plans from the CAD file.

laser pointers

Could any one tell me which laser pointers I need to get for this project? since it is not specified in the article, I bought some simple ones with <1mW output, but the beam is not visible. I have noticed that laser pointers go up to <5mW output, but I am not sure if their beam would be visible. Can someone tell me? thanx a lot in advance

unabox question

I have looked at your web site but cannot find any files that show the dimensions of the pieces. I tried the PDF files and the .skp files. Where else may I look to find them? THank you Matt

Servo avoidance

This was exactly what I was looking for. I was wondering, do you maybe have a sketch written up that uses the servo for object avoidance? A lot of the robots out there use a servo to 'look around' with the ping sensor to determine the best route to go. Would it be possible for you to make something like that? I don't know enough about the processing language (yet!) to be able to make something like that.

Soldering LED wires together

Thanks Mitch and Foobert. I don't mind wiring it as designed, It's just that I had already done it and wrapped the wires. haha. I will take it apart and re-do it as foobert suggested. No problem. FWIW It worked, or was bright anyway, but it may not be functioning correctly as nirvana eluded me the first time I tried it. I did see some funky patterns behind my eyelids though.

Soldering LED wires together

Hello, Dwayne-Clare, Cool that you want to hack the project! The guage of the wire is unimportant -- you can use much thinner wire, if you like, without any problem (since there is not enough current in this project to make any difference). But putting the LEDs in parallel (what you proposed: + to +, and - to -) or series (+ of left-LED to + of LED-output, - of left-LED to + of right-LED, - of right-LED to ground) is not a good idea. As foobert said, there is not enough voltage with two AA batteries to light up the two LEDs in series. And putting LEDs in parallel is really never a good idea (since one LED may hog all of the current from the other, making the LEDs light up at very different brightnesses, or one LED may not light up at all). As designed, each LED has a series resistor, allowing the LEDs to draw different amounts of current, and still allow both to light up at close enough to the same brightness. As designed, the LEDs are connected to different output ports of the microcontroller, but the firmware does exactly the same thing to both LEDs at the same time. But I did it this way so it would be easy to experiment with making each eye blink at different rates. But if you want to reduce the number of wires, then you can use two wires, (for example, using only the two pads for left-eye LEDs), but you'll need to have series resistors for each eye soldered to the LEDs on the glasses -- if you want to do this, add 47 ohm resistors in series with one lead of each LED (for instance, connect the + lead of each LED to the two resistors, and then connect the other side of each resitor together, and then send the connected resistors through a wire to the + pad of one of the LED outputs, and then connect the - leads of the two LEDs together and send that to the ground pad through a wire). Or, use three wires, as foobert suggested: connect the - lead of each LED together and send that to the - pad of one LED output, and connect a wire to the + pad of each of the two LED outputs. Happy hacking, Mitch.

Soldering LED wires together

don't wire the leds in series. two aa cells will not provide enough voltage for that. each led will drop about 2 volts and 3v - 2v - 2v is less than nothing. with the leds wired in parallel you'll have enough voltage, but with just the one resistor on the board in series with both leds your current might be a little low. if the leds are too dim, you could reduce the resistor. or you could use the circuit as designed with three wires - one to the anode of each led and one in common from both of the cathodes.

Soldering LED wires together

Sorry. That was 22 gauge stranded.

Soldering LED wires together

Hi Mitch. Thanks for this great project, I am eager to try it out. I am pretty much done, but I modified things a bit and put the LED's and battery on long leads using 18 gauge stranded wire. I plan on making a box for it all and putting it on my bedside table. I had the idea of soldering the two LED's together, + to + and - to - then running them on two wires to the circuit board. When I got to that point the thought occurred to me that maybe the two LED's are supposed to pulse at a different rate. Does it matter if the LED's are wired together or should I split them up again?

Aquaponics

Hi, Anyone tried to use the garduino as part of a hydroponics system. I am contemplating doing this and would appreciate any advice. Thanks

Felted Fruits and Veggies!!!

I've been felting fruits and veggies for the past couple years and selling them at craft fairs. These look awesome and I'm going to take what I can from them and improve mine!

It's Not Working!!!!!!!!!!

OK, no problem, we'll get you going. First things first, don't plug the motors directly into the Arduino any more. The Arduino can only supply so much current, and it's far less than what's required by the motors. My bad for not mentioning this in the article -- it is actually possible to burn out your I/O pins by connecting motors to them, at least with other microcontrollers I have used. A) Make sure you are running test program 01_Test_Motor_Rotation or 02_Test_Motor_Speed. B) Check ground connections on motor driver board The motor driver board has three pins that are connected to ground. But who's ground? Good question. In addition to being connected to the negative lead on the 9V motor battery, the motor driver ground and the Arduino ground _also_ need to be connected together. This isn't clear from the schematic. So, make sure that at least one of the ground connections on the motor driver board is connected to the ground connection on the Arduino Proto Shield. This place is labeled "GND" on the Proto Shield, and you have doubtless ran that up to your breadboard somewhere. C) Send a photo Email a digital photo to: kris@makezine.com, and I will try to see if I can spot any problems in your wiring. D) Check pins 4,5,6,7 Now we'll check whether pins 4,5,6,7 are functioning OK by replacing the motor driver with an LED and seeing whether the LED lights up. You will need a resistor and an LED for this. Remove the wire connecting Ardiuno pin D4 to the motor controller pin BIn2. Put a resistor into Arduino pin D4. It can be anywhere from 330 up to about 1000 ohm. (If you don't happen to have any resistors in this range... email me what you have and maybe we can come up with some equivalent.) Find an unused spot on your breadboard (not so easy) Connect the resistor to the positive side of an LED by plugging both into breadboard appropriately. (Positive is long lead, or no flat spot on plastic housing) Connected negative side of LED to ground (GND). Run program 01_Test_Motor_Rotation. The LED should turn on briefly, then turn off. (about 1/4 of a second). Repeat with pins D5, D6, and D7. E) Check power connection to motor driver chip Make sure you have wired 5V to the VCC pin on the motor driver chip. If you have a multimeter, put it on volts and make sure it reads 5V when you proble the VCC pin and the GND pin on the motor driver. Check it with all three of the GND pins and each should meter 5V. F) That's all I can think of right now, feel free to email me directly.