Go Down

Topic: 5v motor (Read 1 time) previous topic - next topic

I have my motor plugged into a bread board. If I hook up the lower 5v power and ground to it, I can power the motor. That works like expected.

If I switch the power to output 9 at the top, it doesn't work. My loop function is just a digitalWrite(9, HIGH); and I even tested the output # 9 with an led and my multimeter to make sure it is getting 5v. Why wont the motor work?

zoomkat

In most cases the aduino pins cannot supply sufficient current to power motors.
Google forum search: Use Google Advanced Search and use Http://forum.arduino.cc/index in the "site or domain:" box.

So the 5v power has more current than the others. I see. Thanks

Grumpy_Mike

See this link for more info on how to get round this:-
http://www.thebox.myzen.co.uk/Workshop/Motors_1.html

MarkT

Indeed - you should check that pin 9 still works as input and output in case it has been damaged.  Hopefully it survived.
[ I won't respond to messages, use the forum please ]

Terry King


Indeed - you should check that pin 9 still works as input and output in case it has been damaged.  Hopefully it survived.


Doing Arduino classes with many small (and large) fingers and lots of wires, I felt the need to periodically test the Arduinos that flow back and forth.  I built the tester and software that you can see here:
http://terryking.us/arduino-testing.htm

If there was enough interest I could put together a kit with all the 220 ohm 1% resistors and a raw proto board... Solder it yourself.

If anyone had time and inclination to do a Shield PCB design, I could see about having it made in China; share the (possible?) profits??? Probably all SMT resistors, maybe a FET-driven pin 13 LED and a reset button. Maybe a small beeper to give pass-fail indication. Or maybe KEEP it simple  :smiley-roll-blue:
Regards, Terry King  ..On the Red Sea at KAUST.edu.sa
terry@yourduino.com  LEARN! DO! (Arduino Boards, Sensors, Parts @ http://yourduino.com

MarkT

It would be great if that could be combined with a 'debug' LED shield that shows the state of all pins (one LED per pin).  The voltage divider for testing purposes would have to be below the LED threshold to prevent it turning on LEDs.   In fact if the LEDs are arranged to come on weakly if tri-state, you could probably visually check the pin functions directly as well as use it as a debugging tool.
[ I won't respond to messages, use the forum please ]

ben10

You haven't mentioned what drives your motor is it just arduino? or you have a motor driver on your breadboard where your motor and your arduino connected?

Terry King


It would be great if that could be combined with a 'debug' LED shield that shows the state of all pins (one LED per pin).  The voltage divider for testing purposes would have to be below the LED threshold to prevent it turning on LEDs.   In fact if the LEDs are arranged to come on weakly if tri-state, you could probably visually check the pin functions directly as well as use it as a debugging tool.

Hi Mark,

HHmmmmm.....   (This is a word I learned from 10 years in Semiconductor test)...

mmmmm.. The conflicting desires are to be able to have a very simple, cheap test shield, VS one that can check both tri-state leakage AND source current capability AND sink current capability.  Basically we are testing the pullup and pulldown FETS inside the ATMega, and the weak pullup disconnect FET switch, and the input level sensing circuit leakage. And the board/socket for shorts/opens.

The real simple approach I took in the shield I did basically will fail if ANY pin has excessive leakage to Vcc or Gnd in tri-state, and tests individual source/sink and the Analog inputs over some range. 

I don't see a simple way to check individual pins for leakage + and - and also do source-sink.  I've thought of building a separate leakage test shield.

I can see lots of ways to build a more comprehensive tester with an Arduino Mega test driver and a bunch of FET switches.  But that's a lot more complex. (I've designed testers that took $80,000 to build in quantities of 20 .. but this is just as much fun and probably more...)

Any suggestions on circuitry would be appreciated.. always better with multiple people thinking!

I haven't figured a way to test individual low-current leakage per pin in a passive self-test mode.

I think my design just tests for board/socket continuity and shorts, output pin FET damage and Analog multiplexor/A2D. But this is mostly for those of us with several Arduinos that go in Harms Way like classes and workshops (maybe OUR workshop!), and for me, testing Arduino Clones (Um, "Open Source Copies") better than some factory did, before selling them.



Regards, Terry King  ..On the Red Sea at KAUST.edu.sa
terry@yourduino.com  LEARN! DO! (Arduino Boards, Sensors, Parts @ http://yourduino.com

Go Up