Powering both arduino and android phone by USB

Hi,

I want to have an app in Processing running Android connected via USB-OTG serial to an Arduino Nano or Uno.

The problem is the USB charging port being occupied, battery time is ilimited.

The question is - if I cut the USB cable between phone and arduino, to inject 5V from a wall charger will I break anything?

Otherwise said, can a phone be charged while USB port is in host mode?

Thanks.

That's a very good question! :roll_eyes:

"Powering both arduino and android phone by USB"

A simple USB hub might be the answer.

zoomkat:
A simple USB hub might be the answer.

Doesn't solve the problem at all! :astonished:

The question re-stated is:

When you charge the phone, you supply 5 V into the USB port which it then uses to charge its 3.7V LiPo battery.

When you use OTG, the phone generates - presumably - 5 V out of the USB port in order to power the eternal USB "device". Such a device expects the standard 5 V (or does it?) so the phone would presumably need to synthesise 5 V from its 3.7 V battery..

If you apply an external 5 V supply to the USB port terminals in OTG mode, can it or would it be able to detect that it is being supplied power instead of supplying power and accept that 5 V power in order to charge its battery while it is accessing a device in OTG mode? :roll_eyes:

I have the same concern regarding Apple's Lightning. If a device is plugged in which the phone powers, is it possible to use a piggyback cable to keep the phone charged while this device (audio input for recording) is operating?


Apparently, for OTG, you require something called an "Accessory Charging Adaptor (ACA)"

eBay does not appear to know what that is. :roll_eyes: (No surprises there.)

"If a device is plugged in which the phone powers, is it possible to use a piggyback cable to keep the phone charged while this device (audio input for recording) is operating?"

Per the referenced OTG page, there seems to be some pixie dust involved in the accessory charging adapter setup. As to the question of simply injecting 5v into the USB connections, probably time to simply give it a try. One might need to make a test adapter like exposing the 5v wires on a connecting USB cable and injecting 5v to see if the device indicates it is charging.

They make a cable for this.https://www.ebay.com/itm/Micro-USB-Male-to-USB-Female-Host-OTG-Cable-USB-Power-Y-Splitter-Cable-Cord-US/153786863839
The problem I found is that the phone or tablet must support OTG charging,which a lot of them don't.
When I was messing with a Nexus 7 tablet you had to be rooted and have a custom ROM to enable Otg charging

blimpyway:
I want to have an app in Processing running Android connected via USB-OTG serial to an Arduino Nano or Uno.

Why not just connect the phone and the Arduino using Bluetooth and leave the power connections free for a charging cable?

...R