9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Cant get your radio to work? General Hardware issues?
User avatar
LTMNO
Posts: 1049
Joined: Fri Nov 30, 2012 9:31 pm
Country: Canada
Location: Toronto, Canada

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by LTMNO » Tue Sep 17, 2013 2:07 am

Hi Colin, no worries, I have another TX on order and the 2561 chip coming as well... but i am going to hold off... at this point, just have 2 birds and 1 radio...

Cheers.

Pino.
Custom 9x with M64/Telemetry Mod


frenk73i
Posts: 1
Joined: Wed Sep 18, 2013 2:00 pm
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by frenk73i » Wed Sep 18, 2013 2:26 pm

gruvin wrote:Geoff, you -- and Mike B but I somehow missed it -- have nailed it. Guess what?! ...

There is indeed no digital ground connected to ONLY the HORIZONTAL trim switches. The vertical trim switches get digital ground, while the horizontal ones get only analog ground, which is then passed on up to the pots.

So that's the problem then, for sure now. It also explains why multiple switch presses cause a crash, while holding them down does not. This effect was not satisfactorily explained in previous posts, to me anyway. I'll bet money that a crash occurs only when the switch is released, too.

My confusion clearly came about from assuming that ALL trim and navigation switches would be using the SAME ground circuitry. OMG they are not! So ironically, the problem I originally found when making my G9X v3.2 board work is ultimately the very same issue that causes this other problem.

Inserting the resistors appears to work well enough, by limiting the initial inductor magnetic flux (inductor charge). But it's not in fact addressing the real problem, which is now clearly a back EMF discharge spike from the AVss inductor. But there will still be a spike. Just not quite so big. So it's still not good.

This is just how the spark coil in (especially older) motor vehicles works. Charge a coil at 12V (in that case) and then, when the charge current is disconnected -- by distributor points opening or us releasing our trim switch on our radios -- a back EMF discharge is caused by the very rapidly collapsing magnetic field around the inductor coil. That little 10uH inductor we are using is tiny compared to a motor vehicle coil. But we don't need 33,000 Volts, just to spike our little MCU, either!

So what's the REAL fix?
I'll try to describe it here in text, briefly then get some pictures uploaded after I actually do it.

On my FlySky field radio and at least one of my Turnigy sets, the digital ground wire (from each 12-pin JST connector) is grey and the analog ground is orange. (Some radios of this breed use different colours.)

Procedure (tested on FlySky TH9X radio, with G9X v4.2 board) ...

Step 1.
Remove the two horizontal trim switch PCBs.

Step 2.
Cut the PCB trace that runs from the middle, red wire (common ground in fact, even though its red!) of the two 3-pin connectors on the trim switch PCB, to the trim switch common ground. Do the same for both horizontal trim PCBs. The layout is slightly different on each horizontal trim board. Adjust where you cut accordingly. On the left board (viewed from the back) you will have to cut tracks on both sides. The right hand board (some version of it anyway) require a single cut, on the under-side (opposite side to components.)

Note that there are at least two versions of at least one of these PCBs in existence -- not including how the left and the right are each a little different!

Step 3.
Cut the orange wire where it enters the white, 6-pin wire-to-board header on the removed horizontal trim PCB, as close as you can to the white header, to leave the wire as long as possible.

Do the same for both horizontal trim PCBs.

- - -

In steps 2 and 3, we broke the link running from the two (digital) trim switch grounds, to the two (analog) stick pot grounds -- and disconnected the incoming analog ground (orange wire) entirely, just for now.

In the following steps, we will connect the correct digital and analog grounds to where they should always have been ...

Step 4.
Note where the grey wire goes to on the nearest VERTICAL trim switch board. It should be the middle of the 3-pin wire-to-board header and also the common ground of those two trim switches. Solder a new wire (preferably grey or black) between that vertical switch board's common ground and the pin on the removed horizontal trim board, where the orange wire used to go. Just solder it to the pin on the back of the board. Don't try to solder to the remains of the orange wire.

Do the same for each horizontal trim board, using the nearer vertical trim board as the source for digital ground (grey wire) in each case.

Step 5.
Solder the loose end of the orange wire you cut in step 3 to the common ground pin of the two 3-pin white headers, which go off to each of the nearest stick pots. NOTE: This is NOT the black wire on my radio, but the RED wire, in the middle. That is, do not assume ground equals black, in this case. Red (-ve) and black (+ve) are reversed! (Yeah. I know eh?!)

Do the same with the loose orange wire on the other horizontal trim switchboard.

Step 6.
Lock down the newly soldered wires with hot-glue, to act as cable strain relief. This will prevent the wires breaking way at the brittle solder joint, during future movements within the radio -- mods, etc. This is not optional. It's important. Trust me. ;-)

Step 7. (optional)
If you previously installed them, then remove the additional 1K resistors you added and re-bridge the cut track. This is essentially optional, but those resistors should no longer be needed.

I strongly recommend that ALL Turnigy radio owners perform this corrective patch -- even ATmega64, stock versions.
right bottom side.jpg
"analog ground" refers to the new position for the orange wire.

left top side.jpg
left bottom side.jpg
- - -

An alternative, quick and dirty patch would be to install a reverse EMF capture diode across the AVss, 10uH inductor -- cathode to AVss and anode to Vss. This is the same sort of thing done for relay coils, to prevent back EMF spikes. I won't be trying this one, but it should prevent system crash spikes from using the horizontal trim switches, without doing the above mod and without the 1K series resistors (which otherwise do no harm).

Even quicker/dirty mod -- short out the Vss-to-AVss inductor. I doubt anyone would notice any additional noise on their gimbals or pots, in practice -- especially with only 2.4GHz radio modules in use. It's not ideal, but neither is leaving the radio's wiring wrong, as it is from the factory. A little noise versus a system crash from using trims? It's a no brainer.


HELLO THERE, I JUST WANT TO STRESS THAT YOU DON'T KNOW HOW MUCH I'M VERY THANKFULL, FOR IT FINALLY RESOLVED MY PAIN IN THE ASS PROBLEM WITH A JITTERY SERVO ON MY TURNIGY 9X WITH AN ATMEG64 (STOCK MODULE WITH OPENTX) IN IT, I WAS HOPELESS AND THOUGHT OF PUTTING THE DIY FRYSKY MODULE ON IT. I GUESS THE FRYSKY DIY MODULE HAVE TO WAIT......THANKS AGAIN, THOUGHT OF PASSING THE NEWS TO HELP OTHERS WITH JITTERY SERVO PROBLEMS WITH T9X STOCK MODULE...

User avatar
LTMNO
Posts: 1049
Joined: Fri Nov 30, 2012 9:31 pm
Country: Canada
Location: Toronto, Canada

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by LTMNO » Thu Sep 19, 2013 4:15 am

Just did the digital ground update on M128A Stock 9X Board and it works great, no resets anymore.

Many Thanks!
Custom 9x with M64/Telemetry Mod

davx
Posts: 210
Joined: Sun Sep 15, 2013 7:01 am
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by davx » Mon Sep 23, 2013 9:22 pm

Hi everybody,

I thought it was important to let you know I've experienced the trim rebooting problem with a stock 9X (Atmega 64).
It's a Eurgle 9X bought from R2hobbies the 28/05/2012.
I've made the following mods:
- Programmer cables soldering
- LCD backlight (with transistor)
- Frsky telemetry

I've made the modifications per Gruvin's instructions (thank you !!) and so far, so good.

Perhaps we should warn also users of the stock 9X against this possible problem, a rebooting during a flight (with the throttle warning screen !) could have unfortunate consequences...

Tchao

WendoNZ
Posts: 50
Joined: Fri Dec 21, 2012 4:00 am
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by WendoNZ » Wed Sep 25, 2013 7:14 am

Would it make sense for an admin to sticky this issue and change the subject name to reflect it can happen on any 9X?


User avatar
mbanzi
Posts: 223
Joined: Thu May 24, 2012 5:53 am
Country: -
Location: San Diego, CA

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by mbanzi » Fri Sep 27, 2013 6:53 am

I threw together a Wiki page based on gruvin's post with the fix (also linked from the Hardware Mods page):

http://openrcforums.com/wiki/index.php/ ... Ground_Fix

User avatar
Bill
Posts: 195
Joined: Thu Jul 04, 2013 5:54 pm
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by Bill » Sun Sep 29, 2013 10:29 am

Just a quick note:
Having just done the modification:
It is unnecessary to cut and move the orange wires, if the cuts are made as shown for the left PCB top and bottom that's OK the orange wire analogue ground remains connected to the connectors that go to the pots and the switches are isolated ready for their connection to the digital ground. On the right PCB bottom side don't cut where shown but cut the trace between the switches and the trace running from the orange wire to the connectors that run to the outputs of the pots connector, at the edge of the pad on the switch, this maintains continuity to the analogue outputs, (make the bottom cut as shown), no need to cut or move the orange wire. Connect the digital wires as per instructions.
right bottom side.jpg
right bottom side.jpg (46.19 KiB) Viewed 8172 times
There is also confusion about left and right PCB's but take it that the right PCB is the one you see on your right when looking into the back, (but actually it's the left!)
“A good politician is quite as unthinkable as an honest banker”
They used to say "if you don’t want to work at McDonald’s, go to college." Now they say "if you want to work at McDonald’s, go to college.”

User avatar
mbanzi
Posts: 223
Joined: Thu May 24, 2012 5:53 am
Country: -
Location: San Diego, CA

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by mbanzi » Sun Sep 29, 2013 3:32 pm

Bill wrote:Just a quick note:
Having just done the modification:
It is unnecessary to cut and move the orange wires
Good catch Bill! I have 2 more transmitters I have to do the fix on, I'll take pictures and update the Wiki when I do them.
Bill wrote:There is also confusion about left and right PCB's but take it that the right PCB is the one you see on your right when looking into the back, (but actually it's the left!)
I think referring to the boards the way they are seen when the transmitter is open, is WAY less confusing than their actual orientation when using the transmitter. I will add something to the Wiki to clarify that though.

User avatar
ShowMaster
Posts: 4327
Joined: Thu Dec 29, 2011 3:44 am
Country: -
Location: Los Angeles, CA USA

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by ShowMaster » Sun Sep 29, 2013 3:40 pm

Is this also recommended for m64 standard 9x radios or just those with the upgraded CPU?

davx
Posts: 210
Joined: Sun Sep 15, 2013 7:01 am
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by davx » Sun Sep 29, 2013 3:46 pm

Hi,
I've reported upward that I've been experiencing rebooting with a stock 9X so it's up to you to decide ;)

User avatar
mbanzi
Posts: 223
Joined: Thu May 24, 2012 5:53 am
Country: -
Location: San Diego, CA

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by mbanzi » Sun Sep 29, 2013 3:59 pm

ShowMaster wrote:Is this also recommended for m64 standard 9x radios or just those with the upgraded CPU?
In gruvin's words: "I strongly recommend that ALL Turnigy radio owners perform this corrective patch -- even ATmega64, stock versions."

User avatar
ShowMaster
Posts: 4327
Joined: Thu Dec 29, 2011 3:44 am
Country: -
Location: Los Angeles, CA USA

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by ShowMaster » Sun Sep 29, 2013 4:51 pm

Wow!
Ok, how do I test this malfunction step by step please.

User avatar
Kilrah
Posts: 10295
Joined: Sat Feb 18, 2012 6:56 pm
Country: Switzerland

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by Kilrah » Sun Sep 29, 2013 4:54 pm

If you had it you'd already know by now. But there are thousands of 9Xs out there that work just fine, and a couple that didn't. There are >99% chance there's no issue, but gruvin recommended it in the "better safe than sorry" way.

User avatar
mbanzi
Posts: 223
Joined: Thu May 24, 2012 5:53 am
Country: -
Location: San Diego, CA

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by mbanzi » Sun Sep 29, 2013 11:19 pm

ShowMaster wrote:Wow!
Ok, how do I test this malfunction step by step please.
Using the horizontal trims repeatedly causes the transmitter to reboot. I should mention that none of my stock transmitters ever did this over many years of flying, and after replacing the stock MCU with a M128, only 1 out of 3 did.

Camboui
Posts: 79
Joined: Wed Feb 15, 2012 3:01 pm
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by Camboui » Wed Oct 02, 2013 12:07 pm

Sorry to disturb.
Why are you swapping the CPU (or should I say AVR) ?
Is there any thread about this mod ?
Thanks.

User avatar
MikeB
9x Developer
Posts: 16622
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset, UK

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by MikeB » Wed Oct 02, 2013 12:46 pm

The size of the flash memory on the ATMEGA64 means it has become more difficult to add new features. I have frequently needed to make the code compile into a smaller space so that it will continue to fit. Changing the an ATMEGA128A (or an ATMEGA2561) provides much more flash memory for the firmware, and also provides twice as much EEPROM memory for model storage.
Both alternative processors are now supported by er9x and openTx.

Mike.
erskyTx/er9x developer
The difficult we do immediately,
The impossible takes a little longer!

User avatar
skylark
Posts: 197
Joined: Mon Jul 09, 2012 6:18 pm
Country: -
Location: Oxford, England

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by skylark » Tue Oct 15, 2013 10:12 pm

Bill wrote:Just a quick note:
Having just done the modification:
It is unnecessary to cut and move the orange wires, if the cuts are made as shown for the left PCB top and bottom that's OK the orange wire analogue ground remains connected to the connectors that go to the pots and the switches are isolated ready for their connection to the digital ground. On the right PCB bottom side don't cut where shown but cut the trace between the switches and the trace running from the orange wire to the connectors that run to the outputs of the pots connector, at the edge of the pad on the switch, this maintains continuity to the analogue outputs, (make the bottom cut as shown), no need to cut or move the orange wire. Connect the digital wires as per instructions.
right bottom side.jpg
There is also confusion about left and right PCB's but take it that the right PCB is the one you see on your right when looking into the back, (but actually it's the left!)
Hi Bill,
I have just done this fix by Gruvin incorporating your suggestion. On finishing the mod, the left board's digital groung was totally isolated ready for the connection of the black wire (digital ground connection). However not so on the right goard. Digital ground was still connected to analogue ground. I traced this link to the copper strip on the topside of the right board between the connection blocks in a similar position as on the left board (Topside). I cut this (Thick) trace and the connection was gone. I can't remember seeing any reference to this trace in the posts so far. I could have missed something. That's very possible, grey cells are getting lazy of late. I'm all done and dusted, radio back together. Seems OK on switch on test (no smoke signals, yet). Good to go. Could you check and verify If AOK before I start using the beast in earnest and/ or mod my other radio ?. Both my radios have the same board layout.
Cheers.
Stan.
He who knows not and knows not he knows not, is a fool: SHUN HIM.

He who knows and knows he knows, is a wise man : SEEK HIM

But he who knows not and knows he knows not, is a baby: TEACH HIM.

User avatar
Bill
Posts: 195
Joined: Thu Jul 04, 2013 5:54 pm
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by Bill » Wed Oct 16, 2013 8:02 am

Yes in Gruvins text he wrote that you had to cut the thick piece on the front of right board but he didn't detail it like he did the other side.
It was kind of implied and I cut it like the board on the other side.
Perhaps the definitive Wiki by Mr Mbanzi should emphasise the right hand front cut as well as the left hand cut.
But rest assured you have done the right thing (pun intended) :)
“A good politician is quite as unthinkable as an honest banker”
They used to say "if you don’t want to work at McDonald’s, go to college." Now they say "if you want to work at McDonald’s, go to college.”

User avatar
skylark
Posts: 197
Joined: Mon Jul 09, 2012 6:18 pm
Country: -
Location: Oxford, England

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by skylark » Wed Oct 16, 2013 9:39 am

Hi Bill,
Thanks a lot. Pun accepted. I'll go mod my other radio. Have a great day.
Stan.
He who knows not and knows not he knows not, is a fool: SHUN HIM.

He who knows and knows he knows, is a wise man : SEEK HIM

But he who knows not and knows he knows not, is a baby: TEACH HIM.

viperman3
Posts: 7
Joined: Thu Oct 03, 2013 2:55 pm
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by viperman3 » Sat Oct 26, 2013 2:06 am

Just completed this mod on my FlySky 9X. I have used a continuity tester and when probing between the digital ground and the orange analog ground (with all the appropriate traces cut on both sides of the board and the new black wires connected from the vertical board) I get a continuity beep using my multimeter. Is this behavior consistent. Are the digital and analog grounds somehow tied or should there be two separate grounds, i.e, the multimeter continuity tester should not beep when probing between the digital and analog grounds.

Need some verification of this before I put my Heli fleet in the air.

User avatar
Bill
Posts: 195
Joined: Thu Jul 04, 2013 5:54 pm
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by Bill » Sat Oct 26, 2013 7:31 am

They are tied through an inductor which will read as a short with an ordinary meter you need a milliohm meter to see the difference, as long as you made the cuts and tested there was no connection before you added the black wires you are OK.
“A good politician is quite as unthinkable as an honest banker”
They used to say "if you don’t want to work at McDonald’s, go to college." Now they say "if you want to work at McDonald’s, go to college.”

viperman3
Posts: 7
Joined: Thu Oct 03, 2013 2:55 pm
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by viperman3 » Sat Oct 26, 2013 1:00 pm

Thanks Bill.
How is the circuit path to the vertical trim boards classified as digital ground? I'm trying to understand this and figure out how the 9XR differs from the 9X. So far I haven't been able to locate a similar mod for the 9XR. Only option for that radio is to add the 1k resistors on the switch line.

User avatar
MikeB
9x Developer
Posts: 16622
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset, UK

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by MikeB » Sat Oct 26, 2013 3:43 pm

I don't think the 9XR needs this mod. The 9XR runs both digital and analog ground to the trim switch PCBs so I think, without taking the trim switch board out to check, that it doesn't use the analog ground for the trim switches.

Mike.
erskyTx/er9x developer
The difficult we do immediately,
The impossible takes a little longer!

viperman3
Posts: 7
Joined: Thu Oct 03, 2013 2:55 pm
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by viperman3 » Sat Oct 26, 2013 5:33 pm

Actually, MikeB, my concern is when the soft direction buttons are replaced for tactile buttons. When applying repetitive Left, Right, Up, or Down inputs with the direction pad, the 9XR reboots. One of the fixes I've seen on the forums is to add a break on the D-Pad switch lines and bridge each line with 1k resistor. I checked the carbon resistance on the rubberized pads and they would register approximately a 1k resistance. I was wondering if the 9XR also had a similar design issue as was with the 9X regarding grounding.

User avatar
MikeB
9x Developer
Posts: 16622
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset, UK

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by MikeB » Sat Oct 26, 2013 6:21 pm

The 9X and 9XR use the same circuitry for the 4 direction switches and MENU and EXIT buttons. What has been noticed regarding the trim switches is the M64 doesn't seem to be affected while the M128 and M2561 processors are affected.
Since the 9XR is shipped with a M128 these days it may be affected by the buttons where the 9X with a M64 wasn't. Slight differences in the board layout may also affect things.
As I've said before, I don't like the idea of having a capacitor directly across the buttons, so adding series resistors (1K) is a good idea for the 9X and 9XR. Ideally they are needed for all the buttons AND switches.

Mike.
erskyTx/er9x developer
The difficult we do immediately,
The impossible takes a little longer!

User avatar
bob195558
Posts: 2136
Joined: Sun Dec 16, 2012 7:24 pm
Country: United States
Location: New England, Vermont
Contact:

Re: 9x Radio's Rebooting Problem Horizontal Trims Digital Ground Fix and 9x upgrade to ATmega128A3-AU

Post by bob195558 » Mon Jan 27, 2014 1:24 am

Bill's version of: 9x Radio's Rebooting Problem Horizontal Trims Digital Ground Fix (http://openrcforums.com/wiki/index.php/ ... Ground_Fix)

9x Radio Rebooting Problem Horizontal Trims Digital Ground Fix

Because of the design flaw with the Horizontal Trims in the 9x Radios, it is strongly recommend to do this Digital Ground Fix to all of the 9x Radios.

This is the Horizontal Trims Rebooting / Digital Ground Fix that Bill is recommending: (viewtopic.php?f=95&t=3594&p=61220#p61209)
and also see (viewtopic.php?f=95&t=3594&start=120#p62277).

Because there are several version fixes talked about over several different post here and there in OpenRCforums,
this is a complete set of procedures of Bill's Horizontal Trims Rebooting / Digital Ground Fix.

Edit added (August 18, 2016):
To simplify the wiring, connect (add a wire) from the Digital Ground 2nd plug wire (may be Gray in colored)
to it's proper horizontal Trim mod connection.

This will save soldering a digital ground wire from the Vertical Trim boards to the Horizontal Trims boards.
The Trim board's Trace Cuts still need to be done, see photo's 2 through 7 below.
2nd plug wire to Trim Connection_.jpg
Added to Digital Ground 2nd Gray wire a Purple wire to horizontal Trim board connection.
The view of this picture is of the left side.
1_Horizontal Trims Ground Fix.jpg
Photo #1 of 9x Radio after Bill's version of Digital Ground Fix.
(Older way) Photo # 1 is showing the wires running from there Vertical trim board connection to there Horizontal trim board connection,
(note: first do all the trim board's Trace Cuts, see how on photos 2 - 7 for the trace cuts).
This changes the Horizontal Trims to have Digital Grounds instead of analog grounds which fixes the 9x Radio rebooting problem.
I did have one T9x with a 64 chip that had this rebooting problem, though most 9x radios that have had this rebooting problem
have been 9x radio's using the 128 chips.
2_Left Side Lower Trim Trace Cut.jpg
Photo #2_Left Side Lower PCB Trim Trace Cut
3_Component Left Side Lower Trim Trace Cut .jpg
Photo #3_Component Left Side Lower Trim Trace Cut
4_Right Side Lower Trim Trace Cut.jpg
Photo #4_Right Side Lower Trim Trace Cut
5_Component Right Side Lower Trim Trace Cut.jpg
5_Component Right Side Lower Trim Trace Cut
6_Digital Ground Wire added Left Side.jpg
6_Digital Ground Wire added Left Side
7_Digital Ground Wire added to Right Side.jpg
7_Digital Ground Wire added to Right Side
It was much easier to remove all the (PCB) Trim Boards with the Gimbals
and do all the modifications out on the work bench.
The Horizontal Trim boards need Trace Cuts on both sides of there PCB boards (total of 4 trace cuts).
Then attach on the upper Left side a wire between the Trim PCB center solder connection and it goes to the other Left lower Horizontal Trim board solder connection.
Then do the same procedure to the Right side Trim Boards.

After the work is completed, I found it much easier to then re-install the Trim Boards first
and second carefully placing the wires to where they needed to be.
Third, I then re-install the Gimbals keeping the wire from being pinched between the Trim Switches and the Gimbals.
There is not much room between the Trim Switches and the Gimbals and may cause the Trim Switches to bind and/or stick when the screws are tighten all the way down.
So you may want to try unscrewing them just a little, which may help to free them up enough to work properly.

When you have completing the Horizontal Trims to Digital Ground Fix Mod you may want to consider doing the
Voltage Regulator Mod on your 9x mainboard.
I have done this upgrade mod of replacing the stock 5 voltage regulator to a higher amperage out put (1 to 1.5 amp) 5v regulator
which dose help a lot with the electrical components to be able to work much better.
See here for more info: (viewtopic.php?f=95&t=3819#p70263),
(viewtopic.php?f=95&t=3819#p55562), (viewtopic.php?f=95&t=3819#p55790)
and (viewtopic.php?f=95&t=4281&start=180#p69907).

If there is a need for more info to help better understand how to do this Horizontal Trims to Digital Ground Fix Mod,
let me know and I can add an edit to this posting.
I hope this will be a help for those who are doing the Horizontal Trims to Digital Ground Fix Mod.

Bob, B.
Last edited by bob195558 on Sat Apr 22, 2017 8:26 pm, edited 12 times in total.
Er9x on 9x radio, with Smartieparts Programmer and TelemetrEZ Board.
ErSky9x on Taranis, Sky9x, 9Xtreme radios.

3D Printing upgrades with (CR10 3D Printer): (http://openrcforums.com/forum/viewforum.php?f=85).

User avatar
Bill
Posts: 195
Joined: Thu Jul 04, 2013 5:54 pm
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by Bill » Mon Jan 27, 2014 8:59 am

You must do the pcb cuts on the right side although there are no instructions this is taken as implied.
If you read over our discussion this was brought up by skylark and I affirmed that this must be done both sides.
“A good politician is quite as unthinkable as an honest banker”
They used to say "if you don’t want to work at McDonald’s, go to college." Now they say "if you want to work at McDonald’s, go to college.”

User avatar
bob195558
Posts: 2136
Joined: Sun Dec 16, 2012 7:24 pm
Country: United States
Location: New England, Vermont
Contact:

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by bob195558 » Mon Jan 27, 2014 8:41 pm

:) Hi,
Thank You, Bill for your reply.
I will edit my post so to show all the procedures of your version of the Horizontal Trims Rebooting / Digital Ground Fix modification.

I have found where you and Skylark discussed this issue of implied procedure.
I totally missed this implied procedure completely.

Thank you again for your help, I really appreciate it!

Bob :D
Er9x on 9x radio, with Smartieparts Programmer and TelemetrEZ Board.
ErSky9x on Taranis, Sky9x, 9Xtreme radios.

3D Printing upgrades with (CR10 3D Printer): (http://openrcforums.com/forum/viewforum.php?f=85).

User avatar
Bill
Posts: 195
Joined: Thu Jul 04, 2013 5:54 pm
Country: -

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by Bill » Tue Jan 28, 2014 8:57 am

Welcome :)
“A good politician is quite as unthinkable as an honest banker”
They used to say "if you don’t want to work at McDonald’s, go to college." Now they say "if you want to work at McDonald’s, go to college.”

andrew122
Posts: 3
Joined: Wed Jan 15, 2014 8:48 am
Country: Philippines

Re: 9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

Post by andrew122 » Thu Jan 30, 2014 9:50 am

great.. detailed and informative.


Post Reply

Return to “Hardware”