RE: [Paparazzi-devel] Tiny 2.11 reset problem, solution, noise

[mark.griffin]

There are many ways of reducing/eliminating electrical noise. 
An RF choke on the throttle lead from the electric motor controller/BEC
is a good idea.
I try and eliminate ground loops as much as possible. Observe where the
ground wires are going and keep them in a star arrangement with one
common point.
Unfortunately, the Tiny 2.11 has only a double layer board. The earlier
Tiny v1 was 4 layers and much better at suppressing noise. There has
been talk about going back to a 4 layer board but as far as I know, no
one has produced/is selling one. I think that the extra cost for a
4-layer board is well worth it.
/Mark

-----Original Message-----
From: address@hidden
[mailto:address@hidden On
Behalf Of John Burt
Sent: Tuesday, 14 April 2009 4:38 PM
To: address@hidden
Subject: Re: [Paparazzi-devel] Tiny 2.11 reset problem, solution, noise

Good point Mark,

I'd still like to see a slightly higher current rated PS on board (3A?)
just so the Tiny can drive a reasonable compliment of servos without
fear of resetting.

About the noise issue: I have had noise problems as well. My solution
was to wrap the RC receiver PPM/power cable around an RF choke. Anybody
else have noise problems? Solutions?

J

address@hidden wrote:
> John,
> I think it's wise to keep the 2.25A voltage converter on the Tiny as
it
> is.
>
> From an EMC point of view, other high-power/electrically noisy devices
> such as video transmitters should be isolated from the Tiny and run
off
> their own separate power supply. 
>
> This minimises noise being transferred into the Tiny's somewhat
> sensitive circuits (ADC's, GPS etc). 
>
> Regards, Mark
>
> -----Original Message-----
> From: address@hidden
> [mailto:address@hidden On
> Behalf Of John Burt
> Sent: Tuesday, 14 April 2009 6:50 AM
> To: address@hidden
> Subject: [Paparazzi-devel] Tiny 2.11 reset problem, solution
>
> Like Paul Cox I have run into a resetting problem with my Tiny 2.11.
The
> AP worked fine with my Easystar, with 4 small servos, but when flown
in
> my multiplex Cularis with 6 servos it started resetting in flight
(very
> scary!).
>
> After doing some debugging, I discovered that in the Cularis my servos
> were drawing up to 2A, and adding the 9Xtend modem I was occasionally
> exceeding the 2.25A Tiny power supply limit. This causes the power to
> spike down to 0V, the AP resets and there is a brief loss of control
and
> GPS fix. The AP then reboots, regains GPS and switches to HOLD mode
(in
> my flight plan anyway).
>
> The current solution, as Miles Johnson pointed out, is to power the
> servos (and RX in my case) off another higher capacity 5V converter. 
> This seems to work OK for me, although I haven't flown yet with this
> fix.
>
> However, since others may run into this, I'd suggest that the next
> Paparazzi circuit version include a higher capacity power supply
(e.g.,
> the TI PTR08060W 6A power module). Another reason to beef up the power
> supply is that some Paparazzi users may want to power other devices
such
> as video cameras and transmitters.
>
>
>
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>
>
>
>
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