1 Topic by Testing123

  • Testing123
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Topic: Strange behavior using USB versus 9V as power source

Hi, if I power the Arduino with a USB cable, everything works fine. But after connecting a 9V battery as power source, I get the following:
App version 4.11.9, API 25
Device Started
Bluetooth connection started
Connecting to Bluetooth device xx:xx:xx:xx:xx:xx:xx
Bluetooth device connected
Receiving GUI configuration...
GUI configuration received
Receiving variables...
Device is working
Read timeout error
Read timeout error
Read timeout error
Read timeout error
Board not reply
Disconnect
And everything again...
I have tried all the recommended things from the list on how to proceed in case of problems.
The connection always pops up for a moment, then the app tries to connect, then completely disconnects, but then pops up again, and so on and so on...
Any advice would be appreciated please.

2 Reply by Gunner

  • Gunner
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Re: Strange behavior using USB versus 9V as power source

Most likely not enough power (current) in your 9v source to maintain the WiFi. 

If you are using an actual rectangular 9v battery, then they are notoriously low on output current capacity. 

Better to group up 6 AA batteries in series or even a couple of 18650 LiPo 3.2v cells in series for portable power.  Even a 5v battery bank on the USB would work better than a rectangular 9v.

"And voila, which is French for.......'and then I found out.'" - Ready Player One

3 Reply by kin

  • kin
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Re: Strange behavior using USB versus 9V as power source

I agree with Gunner here. I have some of the cheaper brands of 9V batteries that came DOA and some not lasting a very short time. I really dislike those rectangular 9V's they also are way overpriced for the power they deliver.
Maybe some of the even more expensive brands might work better but you will not find them much cheaper, if at all, that 18650's.