Multiwii brownout on Bluetooth connection

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Batperson
Posts: 18
Joined: Mon May 11, 2015 2:52 pm

Multiwii brownout on Bluetooth connection

Post by Batperson »

Hi,

I am using a HK Multiwii Pro (red board) running a Bluetooth module, GPS and MinimOSD connected to each of the 3 serial ports. [EDIT] The board actually has 4 ports, I am using the 3 at the top of the board - serial port 1 to 3.

I am seeing what appears to be a brownout when I establish a Bluetooth connection, using either EZ Gui on my phone or the Multiwii GUI. The blue and green lights go out on the FC, then a second later it beeps. It seems to cycle like this continuously even if I disconnect the Bluetooth connection.
The MinimOSD also appears to restart continuously at the same time.
If I disconnect either the GPS or the MinimOSD then bluetooth connection works as expected.

The Bluetooth, GPS and Minim are all powered by the +5V on the serial ports. Is this a mistake, are they likely to draw more current than the FC can supply?

Previously I attempted to power the MinimOSD from the +5V on the FC's PWM outputs, which are connected directly to a 5A BEC. However I managed to fry the OSD doing this. I'm not sure how this occurred.

Please share with me what are the best practices when powering devices connected to a Multiwii FC :-)

Thanks.
Last edited by Batperson on Tue May 26, 2015 3:35 am, edited 1 time in total.

FengShuiDrone
Posts: 234
Joined: Wed Dec 24, 2014 1:20 am
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Re: Multiwii brownout on Bluetooth connection

Post by FengShuiDrone »

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Last edited by FengShuiDrone on Fri Aug 07, 2015 4:53 pm, edited 1 time in total.

Batperson
Posts: 18
Joined: Mon May 11, 2015 2:52 pm

Re: Multiwii brownout on Bluetooth connection

Post by Batperson »

No, I'm not using serial 0 I'm using serial 1. I also had to solder header pins, but the BT module works fine. It's only when I have the MinimOSD and GPS running at the same time, and I establish a Bluetooth connection, that things go haywire.

FengShuiDrone
Posts: 234
Joined: Wed Dec 24, 2014 1:20 am
Location: ......

Re: Multiwii brownout on Bluetooth connection

Post by FengShuiDrone »

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Last edited by FengShuiDrone on Fri Aug 07, 2015 4:53 pm, edited 1 time in total.

Batperson
Posts: 18
Joined: Mon May 11, 2015 2:52 pm

Re: Multiwii brownout on Bluetooth connection

Post by Batperson »

Since Bluetooth serial communication was working fine on Serial 1, the only issue being apparent brown-outs on the OSD, it was obviously a power supply problem and not a port/software problem. I tried connecting the VCC and GND connections on the Bluetooth module directly to my 5V regulated power supply and the brownouts no longer occur. I think I will do the same with the GPS, and leave the OSD connected as-is.

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