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Topic: Where is this power coming from? (Read 702 times) previous topic - next topic

simon_schvartzman

As it seems there is no way to disconnect the WiFi shield (already reported in several posts) I'm trying to externally control when the board receives power and when it doesn't.

In order to find out which pin will be the best fit  for my purpose I started by bending the pins that I thought were powering the shield: Vin, 5V, 3V3 - Picture 1

To my surprise the board is not only still getting power but it works as if the connections were still there.- Picture 2 (Green led indicates it is connected to my network)

Magically Pin 5V is getting 5V from somewhere - Picture 3

What am I missing? Or the Arduino besides being a great computer product is also able to generate power by itself ??  :)

Many thanks in advance for any help / hint to accomplish my goal: finding a way to disconnect the WiFi shield in order to save power...

MAS3

You're missing the ICSP connector, it's next to the SD card slot.
That one also has power pins.
Have a look at "blink without delay".
Did you connect the grounds ?
Je kunt hier ook in het Nederlands terecht: http://arduino.cc/forum/index.php/board,77.0.html

MAS3

#2
May 07, 2013, 10:54 pm Last Edit: May 07, 2013, 11:14 pm by MAS3 Reason: 1
Have a look over here.
But be aware that it's likely that disconnecting power pins will not get you what you're after, and will get you some trouble.
The shield might interfere with pins it uses and you might want to use, as there's no way of telling what they will do.
Besides switching the power will also require you to correctly initialize the shield upon repowering it.

Of course you're welcome to try and tell us your findings, we're always interested ;)
Have a look at "blink without delay".
Did you connect the grounds ?
Je kunt hier ook in het Nederlands terecht: http://arduino.cc/forum/index.php/board,77.0.html

simon_schvartzman

Many thanks Mas3 for your prompt and useful answer. I agree with you this doesn't seem to be the best solution but i can't find a decent way to put the wifi shield to sleep when i don't need it...

Will keep looking...

Best!

simon_schvartzman

No luck, I've unçlugged the WiFi shield from the Arduino and connected it using just the ICSP pins.

Now I'm getting the "WiFi shield not present" error message...

All of this because the WiFi.disconnect () doesn't behaves as it should!

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