Fried my Arduino using easydriver and 12v. Need help understanding how

EARLIER I wired up my Arduino Uno to an Easydriver using the instructions on

Dan Thompson: EasydriverTutorials.

AND it worked as expected using a small stepper with 3 or 4.5v DC external power input.

BUT TODAY I tried a higher torque stepper motor rated at 12v and .33A. Plugged the power in and connected the + into M+. (The uno was at this stage not connected to the laptop.) The Uno lit up and smoked (see diagram for location).

a. Naturally I will go out and buy another Uno tomorrow and start again, but how can I avoid frying another, please?

b. Will the Easydriver still be OK?

c. I presume the Uno is trashed. is that correct?

Thank-you for any advice!

The following diagram shows wiring:

So how where you powering the Uno?

Mark

holmes4:
So how where you powering the Uno?

Mark

I just hadn't got round to plugging in the USB.... was that the problem?

a. Naturally I will go out and buy another Uno tomorrow and start again, but how can I avoid frying another, please?

Double check all your wiring twice before adding power!

c. I presume the Uno is trashed. is that correct?

Try it using the blink sketch and USB power and if that works switch to the DC conector. I think you may find its ok with USB and not with the DC jack ( I think your smoke came from the voltage reg.)

b. Will the Easydriver still be OK?

Try it!

Mark

holmes4:
Double check all your wiring twice before adding power!

I tried the blink and nothing. I can see the program being uploaded and then nothing. 'On' is on and LED 13 is on.

The wiring was exactly as the diagram I posted - I wrote it down exactly as I saw it after the blow-up....

Shouldn't the Easydriver protect the Arduino?

Q13) Help! I think my Easy Driver is not working like it should. How can I know if it's become damaged?
A13) One thing you can do is to measure some of the resistances and voltages on the board to see if it has become damaged.

With everything disconnected from the ED, measure the resistance from each of the four motor output pins to GND and M+. All 8 of these measurements should be over 1MOhm.
Again with everything disconnected, measure the resistance between the four motor output pins themselves. And again, all measurements should be over 1MOhm.
Again with everything disconnected, measure the resistance from STEP and DIR to GND and +5V pins. Again, all of these should read greater than 1MOhm.
Now connect just GND and M+. Do not connect anything else to the ED. The LED should come on and stay on. Measure the voltage at +5V to GND. It should be right around 5V.
Now measure the voltage at each of the four motor output pins to GND. Two of them should read at about the same voltage that is at M+ (your power supply voltage - mine is 12V), and the other two should be almost zero - I measure 0.018V.
Also check for any missing components. SparkFun has been known to ship boards with resistors or capacitors missing. See the picture above - there is supposed to be one part missing, but only one. (It's the resistor to the right of the word MOTOR.) If your board has any missing parts, it might not work well.
If all of those measurements pass, it doesn't mean you ED is not smoked, but it does rule out internal shorts, which is the most common failure mode for these driver chips.

You have not say how you connect the power supply to Uno when you not connected to PC.

simonlucas:
EARLIER I wired up my Arduino Uno to an Easydriver using the instructions on

Dan Thompson: EasydriverTutorials.

AND it worked as expected using a small stepper with 3 or 4.5v DC external power input.

BUT TODAY I tried a higher torque stepper motor rated at 12v and .33A. Plugged the power in and connected the + into M+. (The uno was at this stage not connected to the laptop.) The Uno lit up and smoked (see diagram for location).

a. Naturally I will go out and buy another Uno tomorrow and start again, but how can I avoid frying another, please?

b. Will the Easydriver still be OK?

c. I presume the Uno is trashed. is that correct?

Thank-you for any advice!

The following diagram shows wiring:

I would suggest you go here and doublecheck

This is the guy who develops them so should know what he is doing and also note there are various models - make sure you get the right one

Also read the comments on the Sparkfun site about the Pot

I am using this with a fairly large stepper motor off a Picaxe and have not had any problems for more than 2 years - will be shortly changing over to an Arduino for this

Craig

BillHo:
You have not say how you connect the power supply to Uno when you not connected to PC.

I'm normally using the laptop. Would I have had blown the USB port, if I'd had it connected?

Thanks for the stuff about testing the easyD. I've just got a better multimeter along with a new Uno, and will follow the directions.

craigcurtin:
I would suggest you go here and doublecheck
Easy Driver Examples

This is the guy who develops them so should know what he is doing and also note there are various models - make sure you get the right one

Also read the comments on the Sparkfun site about the Pot

I am using this with a fairly large stepper motor off a Picaxe and have not had any problems for more than 2 years - will be shortly changing over to an Arduino for this

Craig

Craig, thanks I'd read a bit of schmalzhaus' page already but the detail started to fry my brain. I'll try and be more selective.

I found a tutorial that explained how to set the pot and then work out the current through to the motor coils. I admit that I only did this for the first motor. Could too much current have cause the problem with the Uno? Otherwise I'm going to hope I caused a short with a loose wire and try again.

I'm also reading an article called 10 ways to destroy an Arduino.

Back up and running. New Arduino, and the Easydriver was still working. Took things a bit more slowly and tested everything. Ended up getting my whole proof of concept prototype up and running.

I'll put the fry-up down to sheer carelessness. Perhaps a loose wire shorted something.

Thank-you for the help.

simonlucas:
Back up and running. New Arduino, and the Easydriver was still working. Took things a bit more slowly and tested everything. Ended up getting my whole proof of concept prototype up and running.

I'll put the fry-up down to sheer carelessness. Perhaps a loose wire shorted something.

Thank-you for the help.

Good to hear - well done - those things are pretty much bullet proof so i would put it down to user error.

Maybe post a pic of the final setup to close this one off and for future reference

Craig

Use this tutorial:

Pot adjusted until motor ran smoothly with basic setup and code. Interval between steps was increased to 3000 microseconds before consistent results obtained for the physical load (ie. no steps lost).