Nathan House

Sorry for not getting back with your sooner...

Very cool project! I built a desktop CNC for drilling PCBs a few years ago and it was a blast. Here's some info on my project:

https://www.foxytron...ne-1st-attempt/

Definitely check out this website if you haven't already: http://www.cnczone.com/forums/

What are the max voltage and current ratings for your stepper motor?

The power supply you're looking at is just fine. The higher the voltage the better (the stepper motor will turn faster), and the current rating just means that's the maximum current it can provide. The current rating can be a little confusing, because it doesn't mean that there will always be 10A flowing through the power supply -- it just means the power supply can provide/supply that much current if the circuit connected to it tries to draw that much.

If the maximum current rating for your stepper motor is less than 750mA (the max current the EasyDriver will supply), then you will want to adjust the output current by turning the potentiometer on the EasyDriver.

If you're new to stepper motors, I just Google'd and found what looks like a decent tutorial for Arduino and the EasyDriver: http://bildr.org/2011/06/easydriver/

TLDR: the power supply and EasyDriver's should be fine for small to medium stepper motors!

Let me know if you have any further questions. I'm happy to help!

Well, the best way to debug a programming problem is to break down the program and test the individual components separately.

So, to start, try making a sketch with only the code needed to make the motors turn. Something like (pseudocode):

turn motors forward

delay for two seconds

turn motors backwards

delay for two seconds

stop motors

Once you have that code working, then you can make a program to test the ultrasonic sensor. Once that's working, you can then combine the two programs.

Does that make sense?

Try making the motor code, and if it doesn't work feel free to post your code here and I'll take a look.

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!

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!

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?