Thread Tools
This thread is privately moderated by DennisH, who may elect to delete unwanted replies.
Mar 27, 2011, 01:07 PM
Registered User
Thread OP
Discussion

Turnigy 9x hardware modifications


Hi all,

Been reading on rcgroups already for a long time, but as a first blog I thought to share the modifications I did on my 9x... I planned on using custom firmware, adding a backlight and running of a 2S LiPo.

(Due to a webhost migration: read this post with pictures here http://www.dennisenan.be/site/rc-hel...modifications/ - or full gallery here: http://www.dennisenan.be/site/turnigy/)

The major mod on the transmitter was on the power supply. I decided to use a 2S LiPo (more mAh's in the same physical size battery than a 3S LiPo). As discussed earlier in this thread, the stock linear power supply in the 9x is not using low-dropout regulators. And there are three in the 9x - not quite efficient. To be able to use a 2S battery I decided/needed to replace them all to avoid e.g. the tx module failing due to the drop out voltage.

So I designed a replacement linear power supply. It drops in place of the stock regulators - this way it's still possible to use the TX's voltage measurement. I based the new power supply on the REG104 1A low-dropout regulator from Texas Instruments. From that family I used the fixed 5V output variant in SOT-223 housing. The voltage drop on this one is at full 1A load 500mV max. At 150mA output current (seem to remember that's how much the TX uses) this drops to less than 50mV (!).

Designed a small (approximately 10mm x 20mm) circuit board, etched and populated it.

I then removed the original 78L05 on the mainboard and switchboard and took out the 78M05 from the tx module. With some creative re-use of existing wiring I feed the output of my power supply to the whole 9x. I also installed s_mack's standalone EL backlight.

For the programmer I used the SparkFun Pocket AVR programmer. It's built into the transmitter as I don't really needed it for anything else anyway (I'm a Microchip guy ). It's hardwired to the main board and uses an USB extension for which I shamelessly borrowed the idea of s_mack's programmer... A few holes were drilled in the battery bay so I'm able to see the status of the programmer.

And finally - the most 'useless' mod ever - replacing the touch buttons with softer clicking ones...


Now the next challenge - getting it to work with my heli's
Last edited by DennisH; Aug 18, 2015 at 02:23 AM.
Sign up now
to remove ads between posts
Mar 30, 2011, 10:17 PM
Registered User
chrispaiva's Avatar
Great job.

I don't have enough skills in electronics but is the power mod really necessary even if the er9x have the option to set power alarms ?
Apr 05, 2011, 03:31 AM
Registered User
Thread OP
Really nessecary? No - not as such. Good to have - yes, definately. In my opinion at least.

The "problem" in the 9x is that the voltage regulators used aren't so called low-dropout regulators. For them to function properly the input voltage has to be approximately 2V more than the output voltage. So in this case, the regulator is for 5V, it needs at least 7V input to operate.

Using a 2S LiPo (6V empty; 8,4V fully charged), you can only use the battery for 1V (given some safety margin).

Changing the regulators to a low-dropout variant basically gives me more runtime. This regulator only needs less than 0,5V more input than the output, which means the regulator is still happy with a supply voltage as low as 5,5V.

So I can now fully use the 2S LiPo until it's empty without issues in the TX, giving me extended runtime without the need to recharge. I have my alarm set at 6,5V giving me plenty of time to land and still have some margin on the battery.

You could also go for a 3S LiPo with the stock regulators, but fully charged (12,6V) this is above the specs of the stock hardware and there are TX's which have burnt out because of this (also resolvable though by e.g. adding a diode between the battery and TX).
Apr 09, 2011, 04:40 AM
Registered User
wallaguest1's Avatar
interesting info!

where did you find the softer buttons? i really hate to hear this "click" "click" so cheap,

any way, the stock flysky model is bad, not? looks like people say it got some drift of about 1 or more in the servos. Maybe it did not deserve the effort to change the regulator in the module and just replace it for a better one.
Last edited by wallaguest1; Apr 09, 2011 at 04:58 AM.
Apr 11, 2011, 04:45 AM
Registered User
Thread OP
I got the buttons from a small online shop in the Netherlands - but you can source them everywhere. Mouser, Farnell, name it... The buttons are 6mm high, no extra ground connection and a pitch of 6mm.

Haven't heard about the drifting, and as it's a Turnigy and not a FlySky the module is not as easily replaceable because of the way they hardwired the antenna.

Anyways, I didn't replace the regulator of the module alone, I replaced all three of them by one. The regulator in the module is removed and just bridged as I'm now feeding a clean 5V straigt to the module from my new regulator.
Apr 11, 2011, 05:03 AM
Registered User
wallaguest1's Avatar
what abouts this ldo reg? its okey ?
http://flytron.com/video-equipments/...regulator.html
i read 7-18v
maybe not has good has the one you used?
Apr 11, 2011, 05:20 AM
Registered User
Thread OP
It's an OK regulator, just keep in mind that the voltage drop of this one is just above 1V. The regulator I used is also from the REG-family of Texas Instruments but with a lower drop out. I haven't looked in detail at the datasheets, don't know if there are other differences.

But if you don't have the ability to create your own PCB's, this might be a nice alternative.
Apr 11, 2011, 05:35 AM
Registered User
wallaguest1's Avatar
Googling LM1117 i just found:

"The LM1117 is a series of low dropout voltage regulators with a dropout of 1.2V at 800mA of load current."

that means the minimum voltaje for 5v should be 6,2v (right?)
Apr 11, 2011, 05:41 AM
Registered User
Thread OP
You're right, lowest input would be 6,2V (flytron says 7V, but you should be able to use it below that as the circuit they use comes straigt from the REG1117 datasheet).

1,2V is what I found in the datasheet too. Well, the TX uses about 200mA, and in that case the drop out would be 1V. But you need to keep some safety margin anyway. 6,2V is maybe a bit low if you're using a 2S LiPo, that 'dies' at 6,0V.
May 13, 2011, 08:41 PM
Registered User
Quote:
Originally Posted by DennisH
Hi all,

Been reading on rcgroups already for a long time, but as a first blog I thought to share the modifications I did on my 9x... I planned on using custom firmware, adding a backlight and running of a 2S LiPo.

(pictures are clickable - or the full gallery here: http://www.dennisenan.be/piwigo/index.php?/category/29)

The major mod on the transmitter was on the power supply. I decided to use a 2S LiPo (more mAh's in the same physical size battery than a 3S LiPo). As discussed earlier in this thread, the stock linear power supply in the 9x is not using low-dropout regulators. And there are three in the 9x - not quite efficient. To be able to use a 2S battery I decided/needed to replace them all to avoid e.g. the tx module failing due to the drop out voltage.

So I designed a replacement linear power supply. It drops in place of the stock regulators - this way it's still possible to use the TX's voltage measurement. I based the new power supply on the REG104 1A low-dropout regulator from Texas Instruments. From that family I used the fixed 5V output variant in SOT-223 housing. The voltage drop on this one is at full 1A load 500mV max. At 150mA output current (seem to remember that's how much the TX uses) this drops to less than 50mV (!).

Designed a small (approximately 10mm x 20mm) circuit board, etched and populated it:

I then removed the original 78L05 on the mainboard and switchboard and took out the 78M05 from the tx module. With some creative re-use of existing wiring I feed the output of my power supply to the whole 9x. I also installed s_mack's standalone EL backlight:



For the programmer I used the SparkFun Pocket AVR programmer. It's built into the transmitter as I don't really needed it for anything else anyway (I'm a Microchip guy ). It's hardwired to the main board and uses an USB extension for which I shamelessly borrowed the idea of s_mack's programmer... A few holes were drilled in the battery bay so I'm able to see the status of the programmer.

And finally - the most 'useless' mod ever - replacing the touch buttons with softer clicking ones...


The result:

Now the next challenge - getting it to work with my heli's

Hi!

Very good work!

Can you post the components values you use in power board?

I'm with DataSheet of REG104 and pin 5 must be connect to Vin. I can't see this imn your board.

[]'s
Ismael
May 15, 2011, 09:05 AM
Registered User
@DennisH

I like you mod, I will be doing something similar with mine - 1 question, when the TX module is powered from the +5v directly I presume it is then powered when you plug a trainer/simulator cable in and when you power it from USB/programmer?

Also, does anyone know where the schematic copy is? I have seen it somewhere and forgot to download/bookmark it. They were in some FCC files I think

Guy
May 16, 2011, 03:08 AM
Registered User
Thread OP
Quote:
Originally Posted by iscarelli
Hi!

Very good work!

Can you post the components values you use in power board?

I'm with DataSheet of REG104 and pin 5 must be connect to Vin. I can't see this imn your board.

[]'s
Ismael
I just used the schematic straight from the datasheet (http://www.ti.com/lit/gpn/reg104-5, page 8, figure 1). Cap values as per that figure too: Cin 0,1F; CNR 0,01F and the extra Cout 1F.

Pin 5 is connected to pin 1 via a trace under the regulator.

Quote:
Originally Posted by Guy_H
@DennisH

I like you mod, I will be doing something similar with mine - 1 question, when the TX module is powered from the +5v directly I presume it is then powered when you plug a trainer/simulator cable in and when you power it from USB/programmer?

Also, does anyone know where the schematic copy is? I have seen it somewhere and forgot to download/bookmark it. They were in some FCC files I think

Guy
I have no experience regarding the trainer cable... Can't really say what the effect would be, sorry...
May 27, 2011, 11:07 AM
Registered User
Dennis, I internally mounted my Sparkfun AVR programmer as well. Do you keep yours connected all the time? I noticed that the programmer's blue led comes on as soon as I turn on the transmitter. Everything works OK, I just wonder if it hurts anything leaving the programmer on all the time. Is it drawing enough current to decrease my battery life?

I tried to switch it to "no power" but then the transmitter won't even turn on.

Just wondering how you have it set up. Thanks,
Jeff
May 27, 2011, 09:21 PM
Registered User
Quote:
Originally Posted by DennisH
I just used the schematic straight from the datasheet (http://www.ti.com/lit/gpn/reg104-5, page 8, figure 1). Cap values as per that figure too: Cin 0,1F; CNR 0,01F and the extra Cout 1F.

Pin 5 is connected to pin 1 via a trace under the regulator.



I have no experience regarding the trainer cable... Can't really say what the effect would be, sorry...
Tks!

Did you cut any track on switch board? Can I have details of this?

[]'s
Ismael
May 31, 2011, 02:24 AM
Registered User
By the way, is it possible simply to short out the on board regulator instead of removing it? I think if you short out the IN and OUT part, the current will simply pass through, so if you put your home made regulator upstream, say after the ON/OFF switch it should just use that supply, the reason I said this is because desoldering may cause burnt-out if inexperienced, why not just short it out for now and leave all component in place and simply feed the whole thing with regulated supply


Quick Reply
Message:
Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Turnigy 9X receiver setup agent1940 Radios 8 Jul 29, 2016 03:20 PM
Contest Turnigy 9X 9Ch Transmitter vs Spektrum DX6i alexbazzi Radios 45 Jul 23, 2011 08:51 PM
Help! Turnigy 9x Radio Reset Problem cintiq Radios 0 Sep 08, 2010 03:00 AM
Question How to program the Turnigy 9X settings for a specific model? djacob7 Radios 1 Sep 05, 2010 07:26 AM