Re: [Paparazzi-devel] Lisa Board Power issue

[Piotr Esden-Tempski]

Hi,

If you look into the wiki page of the Lisa/M you will find this:

http://wiki.paparazziuav.org/wiki/File:LisaM_warning_label.png

So you are right. You should use a BEC instead of powering the Lisa/M directly from the battery. It does work (this is why the wiring diagram you are referring to exists) but it is definitely not a recommended practice.

It is using a linear voltage regulator that has to dissipate at least 0.1A * 9V = .9W if you attach radios and servos to the board you will be above 1W dissipation and likely make the regulator burn.

Using a uBEC and powering the board at 5V from there should be a safe bet. Be careful though, if you decide to not power the BEC and supply power to the board using USB connector you can burn the diode in the circuit. In some cases an unpowered uBEC basically shorts its output pins, you should measure that with a multimeter. Adding a input diode behind the BEC might be a good idea.

I hope this helps.

Cheers,

Piotr

--

Piotr Esden-Tempski

Founder: 1BitSquared

On Jul 21, 2015, at 8:02 AM, zorigb <address@hidden> wrote:

Hello,

I was testing my Lisa/M V2 board and it suddenly burned and stopped working.

The board was powered by the BEC on the ECS. Two servos and the spectrum
receiver were attached to and powered by the Lisa board. The wiring diagram
is shown on the following image:

<http://lists.paparazziuav.org/file/n17200/LisaM_V2_0_wiring_fixedwing_spektrum_elevons.png>
The Lisa board was using a paparazzi code with modifications to the radio
file in order to use the spectrum receiver without the ppm encoder.
The pin labeled VS on the image was soldered on by me. And the analog GND
and ADC1 pins were shorted in order to bind the receiver. GPS, IMU and Modem
are not connected at all.

My question is what could have caused the board to fail. And how could i
prevent it in the future.

Also is using a BEC to power the board through the I2C safer than powering
the board through the servo pins?

Thank you






--
View this message in context: http://lists.paparazziuav.org/Lisa-Board-Power-issue-tp17200.html
Sent from the paparazzi-devel mailing list archive at Nabble.com.

_______________________________________________
Paparazzi-devel mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/paparazzi-devel