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Topic: The arduino mega serial communication (Read 2165 times) previous topic - next topic

new99

What would you do to send an arduino data to the computer? (So that the arduino is connected to a voltage source (because the project is going to be implemented in real life).

Wawa

You shouldn't have started a new thread for the same thing.
Doing so confuses and wastes our time.

forum.arduino.cc/index.php?topic=432547.0

Why can't you just use a common USB lead to communicate with the computer, like everybody else does.
Leo..

sterretje

Why can't you just use a common USB lead to communicate with the computer, like everybody else does.
Leo..
One problem might be that connecting the USB cable forces a reset. I know there is a work-around but not everybody is prepared to modify boards.
If you understand an example, use it.
If you don't understand an example, don't use it.

Electronics engineer by trade, software engineer by profession. Trying to get back into electronics after 15 years absence.

Wawa

Distance might be a factor too, but I can't find any reason in this or in the other thread.
Leo..

Grumpy_Mike

@new99 - did you notice on that picture you posted that the USB connector on that cable is not the same sort of connector as the USB connector on the Arduino. You can not connect them.

What would you do to send an arduino data to the computer? (So that the arduino is connected to a voltage source (because the project is going to be implemented in real life).
I can't see what you are worrying about supplying 7V to to Vin of an Arduino has it regulated down to 5V before it gets to the Arduino. Just plug it in to the computer.

new99

The Arduino has a built in power switch.
Your 7 volt to the power jack takes precedent over the USB 5v from the USB cable.



.
That mean that I can directly connect the arduino to the computer, while the arduino is fed into a source of 7v? (see image)

CrossRoads

Maybe - the autoswitch circuit looks for Vin/2 to be greater than 3.3V to use power from the barrel jack.
There is a diode between the barrel jack and Vin.
At light current loads, the voltage across the diode might be small enough that 7V - Vdiode is > 6.6V; or it may not, and Vin/2 will be less than 3.3V and USB power will be selected.

You could measure Vin at the power header and see what voltage level you are getting.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Wawa

@ OP
So you didn't read/understand the posts after that.

Just use 7.5volt on the DC jack, not 7volt.
7volt might not always override USB supply, 7.5volt will.
Leo..

larryd

If you are able to adjust the power supply potentiometer to get 7.5v, do so, then the Arduino power switching circuit will work properly as mentioned by everyone above.

.
No technical PMs.
If you are asked a question, please respond with an answer.
If you are asked for more information, please supply it.
If you need clarification, ask for help.

Grumpy_Mike

(see image)
Well the ends of the cable are wrong, have you seen what sort of connector attaches to the Arduino?

new99

Thank you very much, the truth has made it difficult for me to understand them for what I translate from English to Spanish and the translation sometimes is not correct.

As mentioned by CrossRoads, there is a diode between the barrel jack and the Vin port.

That means if I feed the arduino in port Vin/barrel jack  with 8V. Since 8v is greater than 6.6 (Vdiode is > 6.6V), then the arduino will automatically select the power supply through the port Vin/barrel jack.

CrossRoads

You are feeding 8V to the barrel jack, or to Vin? Both will result in Vin/2 of more than 3.3V.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

new99

You are feeding 8V to the barrel jack, or to Vin? Both will result in Vin/2 of more than 3.3V.
To the port Vin with 8v

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