Gruvin board 4.1 and simulators

[Michal Hlavinka]

Hi,

after some time flying with AFPD, I tried FS One again (I need my gf's
laptop
with windows for this). FS One works only with their original usb
adapter,
but it does not work with v4.1 board. I used it with t9x+stock board
without
any problem, but with v4.1 board, it no longer works. Do you know what
is
different there, what could cause this?

I tried original hitec usb adapter+v4.1 board and it works fine (with
AFPD).
Also FS One adapter works with hitec optic 6. So,from combinations
optic6+hitec,
optic6+fsone, v41+hitec and v41+fsone, only the last one does not
work. It's
probably more sensitive for voltage levels or something. Did anything
change?

Also possible change for v4.2 board: For master/slave connection and
for simulator
connection, special 3.5 jack connector is used. It's stereo jack with
two extra
switches - they are isolated from signal wires. Only one switch
shorting two wires
when connector is plugged in is used. Unfortunately, it's not possible
to buy that
connector anywhere. At least I did not find where to buy it after this
connector
died in my radio(it's quite complicated and not well built). I
replaced it with
hitec din6 connector. I could use the same wiring as is used in hitec
cables (I
used it because I already had those cables for optic 6). Student end
of connector
has shorted two wires, the same way how that jack connector in t9x
does it. So,
from t9x point of view, there is no functional change. Anyway, I think
it'd be
good if v4.2 could work with standard jack connector. What do you
think?

Michal

[Bryan]

On 8 May 2012 02:34, Michal Hlavinka <mih...@mihlit.cz> wrote:

Hi,

after some time flying with AFPD, I tried FS One again (I need my gf's laptop
with windows for this). FS One works only with their original usb adapter,
but it does not work with v4.1 board. I used it with t9x+stock board without
any problem, but with v4.1 board, it no longer works. Do you know what is
different there, what could cause this?

Sounds pretty strange to me. Did you have the switch turned off? I suppose you did.

I use my 4.1 board almost daily with Phoenix RC flight simulator. It works flawlessly.

Perhaps there's a fault with your 4.1 board? Are you able to put the PPM_OUT signal from the trainer jack on a scope or something?
 

I tried original hitec usb adapter+v4.1 board and it works fine (with AFPD).
Also FS One adapter works with hitec optic 6. So,from combinations optic6+hitec,
optic6+fsone, v41+hitec and v41+fsone, only the last one does not work. It's
probably more sensitive for voltage levels or something. Did anything change?

Yes, the circuitry for the trainer in/out is completely different. But it has also been thoroughly tested for compatibility with other brands of radios, whereas previously (the stock board) would not work with several other brands of radios -- Spektrum and JR included. Now it does.

I think it is more likely to be a fault with the board you have.
 

Also possible change for v4.2 board: For master/slave connection and for simulator
connection, special 3.5 jack connector is used. It's stereo jack with two extra
switches - they are isolated from signal wires. Only one switch shorting two wires
when connector is plugged in is used. Unfortunately, it's not possible to buy that
connector anywhere. At least I did not find where to buy it after this connector
died in my radio(it's quite complicated and not well built). I replaced it with
hitec din6 connector. I could use the same wiring as is used in hitec cables (I
used it because I already had those cables for optic 6). Student end of connector
has shorted two wires, the same way how that jack connector in t9x does it. So,
from t9x point of view, there is no functional change. Anyway, I think it'd be
good if v4.2 could work with standard jack connector. What do you think?

I don't understand the request. Surely no change is required for this to happen, as you yourself have just indicated, having changed to the din connector. What am I missing?

Bryan.

[Michal Hlavinka]

On Tue, 8 May 2012 13:08:02 +1200, Bryan <gru...@gmail.com> wrote:
> On 8 May 2012 02:34, Michal Hlavinka <mih...@mihlit.cz> wrote:
>
>> Hi,
>>
>> after some time flying with AFPD, I tried FS One again (I need my gf's
>> laptop
>> with windows for this). FS One works only with their original usb adapter,
>> but it does not work with v4.1 board. I used it with t9x+stock board
>> without
>> any problem, but with v4.1 board, it no longer works. Do you know what is
>> different there, what could cause this?
>>
>
> Sounds pretty strange to me. Did you have the switch turned off? I suppose
> you did.

yes

> I use my 4.1 board almost daily with Phoenix RC flight simulator. It works
> flawlessly.
>
> Perhaps there's a fault with your 4.1 board? Are you able to put the
> PPM_OUT signal from the trainer jack on a scope or something?

it works with hitec adapter and when I plug headphones in, I hear some
"noise",
it's the same kind of noise as I get from hitec optic 6, just much
loader. Not
too much analyses, but I don't have an osciloscope.

> Yes, the circuitry for the trainer in/out is completely different. But it
> has also been thoroughly tested for compatibility with other brands of

> radios, whereas previously (the stock board) would *not* work with several

> other brands of radios -- Spektrum and JR included. Now it does.

Do you know what exactly got changed? Not from schematic pov, but
what's the
result (I mean higher/lower voltage and similar changes)?

>> Also possible change for v4.2 board: For master/slave connection and for
>> simulator
>> connection, special 3.5 jack connector is used. It's stereo jack with two
>> extra
>> switches - they are isolated from signal wires. Only one switch shorting
>> two wires
>> when connector is plugged in is used. Unfortunately, it's not possible to
>> buy that
>> connector anywhere. At least I did not find where to buy it after this
>> connector
>> died in my radio(it's quite complicated and not well built). I replaced it
>> with
>> hitec din6 connector. I could use the same wiring as is used in hitec
>> cables (I
>> used it because I already had those cables for optic 6). Student end of
>> connector
>> has shorted two wires, the same way how that jack connector in t9x does
>> it. So,
>> from t9x point of view, there is no functional change. Anyway, I think
>> it'd be
>> good if v4.2 could work with standard jack connector. What do you think?
>>
>
> I don't understand the request. Surely no change is required for this to
> happen, as you yourself have just indicated, having changed to the din
> connector. What am I missing?

The problem is that people who use t9x will have adapters with jack
connectors,
so they would probably like to use cables they already have. I've used
hitec
pinout, because I already had hitec cables for optic 6. Unfortunately,
all
types of connectors that have "correct" (or any) pins shorted in the
cable,
so they can be used instead of the switch from original jack connector,
have
ppm_out and ppm_in on separate pins. So I can use it only for simulator
or
as a student (for master, hitec cable expects ppm_in on different pin).

So, the only solutions left are:
1) create yet another different pin-out not compatible with anything
out there.
- On our local discussion forum, they discouraged me from doing this:
"if you
sell your tx in the future, you'd make it difficult for a buyer to use
that
radio if (s)he needs to connect it with different tx/usb adapter."

2) add extra connector (no need to solder it) with ppm_in and ppm_out
before it
goes to the switching logic, so hitec/futaba din (or square) connector
can be
used as a replacement (or any different one that shorts two pins).

3) change schematic so standard jack connector that switches one of the
three
jack pins can be used.

4) maybe there is different solution

well, just writing this I got another idea. I could use usual jack
connector and add
extra switch next to it. It'd require manual switching, but it'd work.
Wonder why
I did not get this idea when I needed it :) So scratch this second
part.

[Bryan]

On 8 May 2012 22:46, Michal Hlavinka <mih...@mihlit.cz> wrote:

...

> Perhaps there's a fault with your 4.1 board? Are you able to put the

> PPM_OUT signal from the trainer jack on a scope or something?

it works with hitec adapter and when I plug headphones in, I hear some
"noise", it's the same kind of noise as I get from hitec optic 6, just much
loader. Not too much analyses, but I don't have an osciloscope.

Close enough for me. Probably not a fault then.

As far as I can figure, the v4 PPM_out signal is close in electrical characteristics to that of a Spektrum DX7. The difference is that the '9X has a 5V peak swing, versus a 3.3V one. IN theory, this should make it even more capable of driving your simulator input. Hmmm. Strange.

> Yes, the circuitry for the trainer in/out is completely different. But it
> has also been thoroughly tested for compatibility with other brands of

> radios, whereas previously (the stock board) would *not* work with several

> other brands of radios -- Spektrum and JR included. Now it does.

Do you know what exactly got changed? Not from schematic pov, but
what's the result (I mean higher/lower voltage and similar changes)?

Same voltage (5V) but series capacitively coupled. So in essence, slightly higher A/C impedance.

There is another possibility. You might want to check that the "Proto" and "PPM frame" setting in the main model menus. For simulator (in theory) they should be the fault settings of 300u (microseconds) and 22.5ms, respectively. You could try increasing the frame length, perhaps.

> I don't understand the request. Surely no change is required for this to
> happen, as you yourself have just indicated, having changed to the din
> connector. What am I missing?

...

The problem is that people who use t9x will have adapters with jack connectors, so
they would probably like to use cables they already have. I've used hitec pinout,
because I already had hitec cables for optic 6. Unfortunately, all types of connectors
that have "correct" (or any) pins shorted in the cable, so they can be used instead
of the switch from original jack connector, have ppm_out and ppm_in on separate
pins. So I can use it only for simulator or as a student (for master, hitec cable expects
ppm_in on different pin).

Sorry. I don't see any problem with that. I must be missing something. What you've described is completely normal and desirable far as I can tell. So the solutions that follow don't carry much weight. But I'll try to comment anyway ...

So, the only solutions left are:
1) create yet another different pin-out not compatible with anything
out there.
- On our local discussion forum, they discouraged me from doing this:
"if you sell your tx in the future, you'd make it difficult for a buyer to use
that radio if (s)he needs to connect it with different tx/usb adapter."

2) add extra connector (no need to solder it) with ppm_in and ppm_out
before it goes to the switching logic, so hitec/futaba din (or square) connector
can be used as a replacement (or any different one that shorts two pins).

3) change schematic so standard jack connector that switches one of the
three jack pins can be used.

I don't see how this has anything to do with the controller board. All the wiring for the PPM_in (trainer) jack is off board. Change it however you like.
 

4) maybe there is different solution

well, just writing this I got another idea. I could use usual jack
connector and add extra switch next to it. It'd require manual switching, but it'd work.
Wonder why I did not get this idea when I needed it :) So scratch this second
part.

Well, OK. But I'm afraid I still do not understand the problem in the first place. Sorry. :-/  Surely you can simply wire in any kind of jack you like. There's nothing on the controller board to stop you.

--
Bryan.

[Michal Hlavinka]

can't do that. My board just died when I turned it on (nothing plugged
in) :(
I just heard vibrating motor together with "pufff", there was some
light and
board is visibly fried on at least two places (C32 and C1,C6,Q10,U1).

>
>> I don't understand the request. Surely no change is required for this to
>> happen, as you yourself have just indicated, having changed to the din
>> connector. What am I missing?
>
> ...
>> The problem is that people who use t9x will have adapters with jack
>> connectors, so
>> they would probably like to use cables they already have. I've used hitec
>> pinout,
>> because I already had hitec cables for optic 6. Unfortunately, all types
>> of connectors
>> that have "correct" (or any) pins shorted in the cable, so they can be
>> used instead
>> of the switch from original jack connector, have ppm_out and ppm_in on
>> separate
>> pins. So I can use it only for simulator or as a student (for master,
>> hitec cable expects
>> ppm_in on different pin).
>>
>
> Sorry. I don't see any problem with that. I must be missing something. What
> you've described is completely normal and desirable far as I can tell. So
> the solutions that follow don't carry much weight. But I'll try to comment
> anyway ...

Well, the point is that systems that use shorted wires (replaces the
switch
from jack connector) have (expects) ppm_in and ppm_out on different
pins, so
you can use your radio only as a student or only as a master. If you
connect
both pins together, you'll just short ppm_output(or input), mostly to
the ground.

>
> So, the only solutions left are:
>> 1) create yet another different pin-out not compatible with anything
>> out there.
>> - On our local discussion forum, they discouraged me from doing this:
>> "if you sell your tx in the future, you'd make it difficult for a buyer to
>> use
>> that radio if (s)he needs to connect it with different tx/usb adapter."
>>
>> 2) add extra connector (no need to solder it) with ppm_in and ppm_out
>> before it goes to the switching logic, so hitec/futaba din (or square)
>> connector
>> can be used as a replacement (or any different one that shorts two pins).
>>
>> 3) change schematic so standard jack connector that switches one of the
>> three jack pins can be used.
>>
>
> I don't see how this has anything to do with the controller board. All the
> wiring for the PPM_in (trainer) jack is off board. Change it however you
> like.

Well, the ppm_in/ppm_out switching is on the board and for
student/master mode,
it expects bat+ shorted to extra wire. This can't be done with standard
jack,
you need jack with extra switch - not connected to any of the jack
signal
pins - and it's impossible to buy anywhere. If it worked with gnd
instead of
bat+, standard jack could be used

>
>
>>
>> 4) maybe there is different solution
>>
>> well, just writing this I got another idea. I could use usual jack
>> connector and add extra switch next to it. It'd require manual switching,
>> but it'd work.
>> Wonder why I did not get this idea when I needed it :) So scratch this
>> second
>> part.
>>
>
> Well, OK. But I'm afraid I still do not understand the problem in the first
> place. Sorry. :-/ Surely you can simply wire in any kind of jack you like.
> There's nothing on the controller board to stop you.

Since standard jack+extra slide switch can be used as a
replacement(recent finding),
it's probably not worth wasting the time with it :)

[Bryan]

On 10 May 2012 09:44, Michal Hlavinka <mih...@mihlit.cz> wrote:

...

can't do that. My board just died when I turned it on (nothing plugged
in) :(
I just heard vibrating motor together with "pufff", there was some
light and
board is visibly fried on at least two places (C32 and C1,C6,Q10,U1).

Oh no! :-/
 

>> I don't understand the request.

...

> Sorry. I don't see any problem with that. I must be missing something.

Well, the point is that systems that use shorted wires (replaces the
switch from jack connector) have (expects) ppm_in and ppm_out on different
pins, so you can use your radio only as a student or only as a master. If you
connect both pins together, you'll just short ppm_output(or input), mostly to
the ground.

Yes, agreed. But if it is in anyway possible to even conceive of running in both slave and master mode at the same time, let alone actually realising such a thing, then I cannot fathom how it could work. Can you give a practical example of how this could operate or what it would be used for?
 

...
> I don't see how this has anything to do with the controller board. ...

Well, the ppm_in/ppm_out switching is on the board and for
student/master mode, it expects bat+ shorted to extra wire.

Hmmm. I thought it was just grounded. I can see how that could not be done with a standard/traditional audio jack -- perhaps not even the stereo ones, with two switches.
 

This can't be done with standardjack, you need jack with extra switch - not connected to any of the jack signal pins - and it's impossible to buy anywhere. If it worked with gnd
instead of bat+, standard jack could be used.

Right. Got you. Finally.

Since standard jack+extra slide switch can be used as a replacement(recent finding), it's probably not worth wasting the time with it :)

I will look at this when I get home and can easily view the schematic again. A build option could be added to reverse the polarity (sense) of the "trainer" switch, to allow switching to ground instead of bat+ (which I also need to confirm for myself. Sounds odd. But hey.) Such a build option / reversal would also require an external pull-up resistor (guessing at this stage). But that shouldn't be much of a problem.

--
Bryan.

[Bryan]

Silly me. Having collected my thoughts/memories some more on the drive home, I realised I was confusing "RF_power_sense" with the trainer jack's "power on" switch. The latter is not a digital input of course, but  a direct "power on" bypass. The firmware then checks the rf+power_sense digital input to determine if the main power switch is on or not.

However, with the new circuitry we have for "soft off" (holding the power on by logic control) we could probably still devise a fairly simple logic-to-ground signal to replace the BATT+ signal at the trainer jack. I still haven't looked at the schematic, but I think it would be as simple as a single series resistor, switched to ground at the trainer jack. At worst, yet another NPN transistor might be needed.

- - - -

Do let me/us know when you find out what causes the tragic short-circuit! I hope it's repairable.

Bryan.

[Bryan]

On 13 May 2012 13:34, Bryan <gru...@gmail.com> wrote:

I just heard vibrating motor together with "pufff", there was some
light and board is visibly fried on at least two places (C32 and C1,C6,Q10,U1).

Looking at the PCB layout and schematic, my best guess would be that regulator U4 suffered an internal collapse, shorting BATT+ to ground. Or, depending on the exact place of the "charcoal", maybe even C32 itself shorted out internally. But the latter would not explain the vibrator motor starting up.

Highly frustrating.

If this is one the of the "fully assembled" Chinese factory boards sent to you, then the option to return it for replacement or some kind of compensation / assistance is available. I have kept stock of two spare boards -- both of which were heat damaged (by me, when replacing the LCD sockets) but repaired to working order. So we can look at options there. Of course, the shipping time will be frustrating slow. Either way, I'd like to see you back up and running in the most economic way we can manage, together.

Bryan.

[x3mfly]

Hi Guys!

U4 is best candidat to be reason of this (IMHO), i have expirienced not once same effects with another TI chips, they very sensitive for PCB layout!!! small overload and they puffff, sometime with red(fire) dot and smoke!

and another one issue there with soft off and jack presence, there is capacitor i have to remove C63 to get it working stable with soft power off.

not need to add another one transistor, but need to replace resistive logic with diode logic i think, instead of R111,R112 and D5 need to be as BAT54C + one resistor, bounce cancelling circiuts need to be in mechanical switch only, not need to be in logical circiut....

Max.

воскресенье, 13 мая 2012 г., 6:28:17 UTC+4 пользователь Gruvin написал:

[Michal Hlavinka]

thread split

> > Well, the point is that systems that use shorted wires (replaces
> > the switch from jack connector) have (expects) ppm_in and ppm_out
> > on different pins, so you can use your radio only as a student or
> > only as a master. If you connect both pins together, you'll just
> > short ppm_output(or input), mostly to the ground.

> Yes, agreed. But if it is in anyway possible to even conceive of
> running in both slave and master mode at the same time, let alone
> actually realising such a thing, then I cannot fathom how it could
> work. Can you give a practical example of how this could operate
> or what it would be used for?

I don't completely understand you here. I think you did not understood
me here correctly. With "so you can use your radio only as a student or
> > only as a master" I meant that you'd be stuck with only one option
which would depend if you wire ppm to ppm_in or ppm_out, but you'd
loose
to use it the other way, because if you connect ppm to both ppm_in and
ppm_out pins (on din6 connector or other connector you're trying to be
compatible with), you'd just shortcut ppm with ground (student cable
has
often ppm_in shorted with ground).

> > > I don't see how this has anything to do with the controller board. ...

> > Well, the ppm_in/ppm_out switching is on the board and for
> > student/master mode, it expects bat+ shorted to extra wire.

> Hmmm. I thought it was just grounded. I can see how that could not be done
> with a standard/traditional audio jack -- perhaps not even the stereo ones,
> with two switches.

Yes, that's my point. No available connector can be used as a
replacement.
There is no easy way how to repair it if that connector breaks.

> I will look at this when I get home and can easily view the schematic
> again. A build option could be added to reverse the polarity (sense) of the
> "trainer" switch, to allow switching to ground instead of bat+ (which I
> also need to confirm for myself. Sounds odd. But hey.) Such a build option
> / reversal would also require an external pull-up resistor (guessing at
> this stage). But that shouldn't be much of a problem.

> Silly me. Having collected my thoughts/memories some more on the drive
> home, I realised I was confusing "RF_power_sense" with the trainer jack's
> "power on" switch. The latter is not a digital input of course, but a
> direct "power on" bypass. The firmware then checks the rf+power_sense
> digital input to determine if the main power switch is on or not.

> However, with the new circuitry we have for "soft off" (holding the power
> on by logic control) we could probably still devise a fairly simple
> logic-to-ground signal to replace the BATT+ signal at the trainer jack. I
> still haven't looked at the schematic, but I think it would be as simple as
> a single series resistor, switched to ground at the trainer jack. At worst,

> yet *another* NPN transistor might be needed.

[Michal Hlavinka]

thread split

>>> I just heard vibrating motor together with "pufff", there was some
>>>> light and board is visibly fried on at least two places (C32 and
>>>> C1,C6,Q10,U1).
>>>>
>>>
>> Looking at the PCB layout and schematic, my best guess would be that
>> regulator U4 suffered an internal collapse, shorting BATT+ to ground. Or,
>> depending on the exact place of the "charcoal", maybe even C32 itself
>> shorted out internally.

I've checked my board together with schematics and it seems that C32
burned
for no know reason. Just by looking at it, there seems to be no damage
to U4. Also it's input capacitor and it's "far away" from main
troublemakers
(voltage regulators). Looking at BOM.xls, it should withstand 16V,
so there's no reason for dying. This probably caused damage of the Q10.

Looking at C1, C6, U1 mentioned in previous email, they seem covered
with
foreign soot. After cleaning and checking with magnifier, they seem
intact.

I took a picture of my board:
http://mihlit.cz/smetiste/burnedboard.jpg

>> But the latter would not explain the vibrator motor
>> starting up.

My battery was not fully charged at that time and with battery alarm
set to
paranoid high level, I got beep and vibration alarm when I turned my
radio on. It was not the first time it happened (alarm on turn on),
just this
time it died after 0.2-0.3 s (guess).

Also I should note I have quite big vibration motor (20mm diameter,
25mm length). I don't know what other people use, but I read that
someone
wanted to use motor from cell phone. Anyway, R0 of that motor is 8 ohm,

so its power demand should be low enough for that regulator.

>>
>> Highly frustrating.

yes

>> If this is one the of the "fully assembled" Chinese factory boards sent to
>> you, then the option to return it for replacement or some kind of
>> compensation / assistance is available.

It's the fully assembled board. There does not seem to be big damage,
so I think
I should be able to repair it myself. Main voltage regulators are
intact,
so mcu should not be damaged.

Michal

[Michal Hlavinka]

On Sun, 13 May 2012 19:43:18 +0200, Michal Hlavinka <mih...@mihlit.cz>
wrote:

> thread split
>
>>>> I just heard vibrating motor together with "pufff", there was some
>>>>> light and board is visibly fried on at least two places (C32 and
>>>>> C1,C6,Q10,U1).
>>>>>
>>>>
>>> Looking at the PCB layout and schematic, my best guess would be that
>>> regulator U4 suffered an internal collapse, shorting BATT+ to ground. Or,
>>> depending on the exact place of the "charcoal", maybe even C32 itself
>>> shorted out internally.
>
> I've checked my board together with schematics and it seems that C32
> burned
> for no know reason. Just by looking at it, there seems to be no damage
> to U4. Also it's input capacitor and it's "far away" from main
> troublemakers
> (voltage regulators). Looking at BOM.xls, it should withstand 16V,
> so there's no reason for dying. This probably caused damage of the Q10.
>
> Looking at C1, C6, U1 mentioned in previous email, they seem covered
> with
> foreign soot. After cleaning and checking with magnifier, they seem
> intact.

I carefully removed their cases with 1mm diamond mill and desoldered
remaining pads. Board was damaged under Q10 in top left corner - glue
under
the pad is burned, but there is nice spot near, so it can be fixed with

solder bridge.

The worse is that no local store has replacement sot-23 p-mosfet with
similar/better parameters, so it's another delay.

In Farnell, it's out of stock - I'd have to buy it from oversea
warehouse - with additional cost $35.
I'll take SI2319DS-T1-E3 instead of SI2319DS-T1-GE3. Looking at their
parameters, I can't see any difference, except the first one
costs 1.5x more. Does anyone know, what's the difference between them?

[Cam]

>In Farnell, it's out of stock - I'd have to buy it from oversea
>warehouse - with additional cost $35.
>I'll take SI2319DS-T1-E3 instead of SI2319DS-T1-GE3. Looking at their
>parameters, I can't see any difference, except the first one
>costs 1.5x more. Does anyone know, what's the difference between them?

Si2319DS-T1-E3 (Lead (Pb)-free).
Si2319DS-T1-GE3 (Lead (Pb)-free and Halogen-free)

I can post you one if you want, just email me your address.

--
Cam

[Michal Hlavinka]

Interesting, halogen-free is cheaper. Anyway, they have the halogen
version
in stock and I'll buy a few other parts, so I'm going to buy it there.
They are usually pretty fast with shipping.
Anyway, thanks for your offer, I appreciate it.

Michal

[Bryan]

On 14 May 2012 04:48, Michal Hlavinka <mih...@mihlit.cz> wrote:

thread split

...

I don't completely understand you here. I think you did not understood
me here correctly. With "so you can use your radio only as a student or
> > only as a master" I meant that you'd be stuck with only one option
which would depend if you wire ppm to ppm_in or ppm_out, but you'd
loose
to use it the other way, because if you connect ppm to both ppm_in and
ppm_out pins (on din6 connector or other connector you're trying to be
compatible with), you'd just shortcut ppm with ground (student cable
has often ppm_in shorted with ground).

I still don't understand. Are you saying that some trainer port schemes have separate PPM_IN and PPM_OUT pins? I've only ever dealt with the 2-wire system, where one wire is shared for both. Of course, both signals are available separately, further down the chain in the circuitry. But we won't be messing about with it, since what we have is very close to one of the big brand methods and works just fine (usually.)

--
Bryan.

[Michal Hlavinka]

On Wed, 16 May 2012 17:49:29 +1200, Bryan <gru...@gmail.com> wrote:
> On 14 May 2012 04:48, Michal Hlavinka <mih...@mihlit.cz> wrote:
>
>> thread split
>> ...
>> I don't completely understand you here. I think you did not understood
>> me here correctly. With "so you can use your radio only as a student or
>> > > only as a master" I meant that you'd be stuck with only one option
>> which would depend if you wire ppm to ppm_in or ppm_out, but you'd
>> loose
>> to use it the other way, because if you connect ppm to both ppm_in and
>> ppm_out pins (on din6 connector or other connector you're trying to be
>> compatible with), you'd just shortcut ppm with ground (student cable
>> has often ppm_in shorted with ground).
>>
>
> I still don't understand. Are you saying that some trainer port schemes
> have separate PPM_IN and PPM_OUT pins? I've only ever dealt with the 2-wire
> system, where one wire is shared for both.

Different part of world, different brands used :) Here, the most
popular
brands are (in this order): futaba(high-eng for those who prefer
quality
over price), hitec(middle class) and spektrum(for beginers, because
it's
the most often radio in RTF sets). Only the last one have 2wire
system(some futabas too, but not the most used ones),

http://www.mftech.de/buchsen_en.htm

[Michal Hlavinka]

>>>> I just heard vibrating motor together with "pufff", there was some
>>>>> light and board is visibly fried on at least two places (C32 and
>>>>> C1,C6,Q10,U1).
>>>>>
>>>>
>>> Looking at the PCB layout and schematic, my best guess would be that
>>> regulator U4 suffered an internal collapse, shorting BATT+ to ground. Or,
>>> depending on the exact place of the "charcoal", maybe even C32 itself
>>> shorted out internally.
>
> I've checked my board together with schematics and it seems that C32
> burned
> for no know reason. Just by looking at it, there seems to be no damage
> to U4. Also it's input capacitor and it's "far away" from main
> troublemakers
> (voltage regulators). Looking at BOM.xls, it should withstand 16V,
> so there's no reason for dying. This probably caused damage of the Q10.
>
> Looking at C1, C6, U1 mentioned in previous email, they seem covered
> with
> foreign soot. After cleaning and checking with magnifier, they seem
> intact.
>
> I took a picture of my board:
> http://mihlit.cz/smetiste/burnedboard.jpg

After replacing C32 (with 22uF/20V tantal, same size) and Q10,
board is back alive :) So there really was not any other damage.

[Cam]

Excellent good news.

>After replacing C32 (with 22uF/20V tantal, same size) and Q10,
>board is back alive :) So there really was not any other damage.
>

--
Cam

[Bryan]

On 18 May 2012 09:32, Michal Hlavinka <mih...@mihlit.cz> wrote:

...

After replacing C32 (with 22uF/20V tantal, same size) and Q10,
board is back alive :) So there really was not any other damage.

Cool. :-D