7 replies to this topic

[MichaelSchaap]

I built the robot and the breadboard MELTED at two servo leads! The batteries we're hot too. I disassembled the wires to redo. What could possibly be wrong. I'm gonna construct this again. Obviously not using the MELTED connections of the breadboard.

Any thoughts?

Michael

[Nathan House]

You let out the magic smoke!! 

 

Sounds like a short-circuit. Can you post a picture on here, or upload it somewhere else and post a link to it? Actually, several pictures showing the battery pack, breadboard, and Arduino wiring would be helpful.

 

Do you have a multimeter?

[MichaelSchaap]

I'm sorry. I probably should have kept it all together. I took it apart to redo. I do have a multimeter. What can I look for when I rebuild this so the same thing doesn't happen again?

Michael

[Nathan House]

No worries.

 

A good rule of thumb is to always check for short circuits before powering up any circuit. The way you do this is by turning your multimeter to the resistance mode (it should have an "Ohm" symbol on it, and also make sure the leads are in the correct ports on the multimeter) and then measuring the resistance from GND to each of the different power nets in the circuit (a power net is a collection of wires connected together that are at a certain voltage, such as 5V).

 

In the case of this robot, after you reassemble it, check the resistance from the GND net (all of the GND wires on the robot should be connected together in some fashion) to each of the two power nets (5V output on the Arduino and the wire coming from the battery pack). If the resistance is low, like 0 Ohms or only a few Ohms, then you have a short circuit, which is bad for the reason you discovered (too much current flows through the wires and melts them).

 

This looks like a good video on basic multimeter usage:

 

 

Let me know if you need any help!

[MichaelSchaap]

Ok. I got it wires up again. Nothing melted. I also ran the blink program to make sure the board is good. Everything is good.

It's running, however the Rx light on the Arduino is just blinking. Its not moving. Just blinking. How long does the program take to download? Or is something different wrong?

[MichaelSchaap]

I let it blink for 5 minutes. Does it need longer then that?

[MichaelSchaap]

Thanks for your help by the way. I'm real excited to get this working.

[Nathan House]

Great, glad you got it powered on alright.

 

Ok. I got it wires up again. Nothing melted. I also ran the blink program to make sure the board is good. Everything is good.

It's running, however the Rx light on the Arduino is just blinking. Its not moving. Just blinking. How long does the program take to download? Or is something different wrong?

 

What code did you download? Was it the full program at the end of the tutorial? If so, try starting at the beginning of the programming section and test each piece of the program one at a time. When you're trying to debug a program, the best approach is to test small parts of it separately so that you can more easily identify the problem.

 

It usually takes something around 5-10 seconds to download to the Arduino. If you look at the output at the bottom of the Arduino IDE, it will show you messages throughout the downloading process and will say something like "download completed" when done.

 

I let it blink for 5 minutes. Does it need longer then that?

 

The program will start running as soon as it finishes downloading. You won't have to wait.

 

Thanks for your help by the way. I'm real excited to get this working.

 

Any time!