Transform a cheap RC Transmitter with Custom Firmware

The Turnigy 9x is a cheap Chinese radio transmitter widely sold by hobby king and other retailers under a variety of names. This is a computerized radio transmitter and is already a great deal for the price ($53 currently) and pretty capable if you can figure out how to use the stock firmware. The microcontroller running the show is a common ATMEGA64 type and is not code protected, so several groups of dedicated hobbyists have completely rewritten their own firmware versions that vastly improve the radio and are open source to boot. This instructable will show the steps required to modify your radio and reflash it with the firmware of your choice. 

Step 1 Tools and materials

For this instructable I used:
an old IDE cable,
some other bits of wire,
2x6 pin header,
solder,
hot glue.

you will also need:
a soldering iron, 
hot glue gun,
small saw,
wire cutters/strippers,
an AVR ICSP programmer, I used a USBasp
a PC.

Comments

[Johnny32]

Hi
i would like to install a fw to my 9x tx.
First i need to know what differences are coming between the existing fws to make my choice.
And also i would like to place a knob to use as throttle cut (like the one on the SPECTRUM DX6i). So i have to replace an existing switch or i can add it and add a progam issue and how can i do it (cause i have no knowledge on that).
If u preffer mail me your answer.
Thanks a lot
John.

[hivoltage]

There are three major custom firmwares for this radio currently: th9x, er9x and radioclone. they each have a different feature set. I am not sure exactly what features they have that the stock firmware does not because I actually never used the stock firmware, I installed er9x right away. nobody has made a side by side comparison chart or anything like that because the custom firmwares are always updating and adding new features. You will have to go to the project pages for each and decide for yourself which you would like to use. I did not see that the dx6i uses a knob for throttle cut, but I am sure you can use any of the previously mentioned custom firmwares to mix both the throttle stick and a switch or knob to the throttle channel easily.

[pastaking]

Please don't hotglue the ribbon cable to the chip. Strain could pull the chip off the board!!

[askjerry]

Not likely going to happen... the chip is soldered to the board by multiple pads... each pad by it's self would likely take 1/2 pound... to yank that chip off the board would take at least 30 pounds... likely closer to 50. As for the glue, it melts at about 180F whereas the solder melts about 600F so that is not going to affect it either.

That chip will likely not even get warm during use... it's not a motor driver or anything of that nature... I have completely encapsulated them in epoxy to make them waterproof... with no issues.

Jerry

[hivoltage]

Disregarding the fact that hot glue does not stick strongly and that there's little to no strain on the ribbon cable, if there's something pulling on your radio hard enough to pull off a surface mount chip you have larger problems than a bit of hot glue.

[illfixthatone]

haha my thoughts exactly

[pastaking]

That's a point, but with the hotglue I use it takes a bit of work to pull it of a surface when it is cool. (Sorry for the delay, I lost internet for a while)

[Bizwenth]

I agree with hivoltage on the strain issue, but you be adding heat to the chip by using hot glue, as well if the chip makes any heat at all the glue will help hold it in the chip.

[hivoltage]

The temperature of hot glue does not even begin to approach the temperatures used to create that board in the first place, they use solder paste applied with a stencil then pick and place machines populate all the parts before the entire board goes into a reflow oven where it heats up to the temperature required to melt the solder and attach all the components. A dab of hot glue on the top is not going to be enough to damage it in the least. as far as the glue impeding the transfer of heat away from the chip, it is just a microcontroller. The datasheet for this device says that even working at its maximum clock speed it will not consume more than 20 mA maximum, about the same current as a single 5mm LED, so heat dissipation is not really an issue.

[John_Edward]

As the firmware is constantly updated, I'd recommend making a connector cable for this.

You can make one from the left-over IDE cable and some two-row pin headers.

Or, if your programmer uses a 6pin ISP cable and you did the internal wiring correct, then you can just stick the pin headers straight between them like I do :P

[John_Edward]

You can also do the hole for the plug with a soldering iron, an xacto knife and a small square file.

Poke the plastic with your soldering iron, cut the now soft left-over plastic, and finish with a file.
Rinse and repeat, a neat hole in around 20minutes.

[John_Edward]

You can also take the plug gently apart, saving the back pieces, take the cable out, put the plug back together, saw from the end of the plug, and then putting the cable back.
Saves a lot of work as you don't have to solder anything.

That was how I did it :)

As a bonus,the end of the plug has that little notch on the side, and also the extra part for the assembly, making it very simple to remember which side was pin number one.

You just have to check which pin is which cable before soldering them to the microcontroller.

[Ben The Builder]

So I'd really like to know, I looked at getting this remote, and really wasn't sure if it was worth it (maybe it doesn't actually work) and I really couldn't tell from the reviews. I talked to a guy that works for hobbico and he said it's a gamble, does anybody have an advice on whether or not to get the Turnigy 9x?

[hivoltage]

obviously I got it, and mine works great. Range seems to be very good, it feels pretty well made, and with the addition of custom firmware it has tons of features. Since writing this instructable I finished my RC flying wing and have gone and flown it several times now, and this transmitter has worked admirably. It takes care of the elevon mixing for the wing, as well as adding exponential rates so that I can have both fine control for steady flying and large throws for different maneuvers. Its really an unbelievable deal for what you get: a 9 channel fully computerized 2.4 GHz radio transmitter with customizable firmware.That said, it is definitely a bit of a gamble, since although it has a warranty return shipping to HK costs nearly as much as the radio itself. If you get a good one, this radio is great and a phenomenal deal, but there is a nonzero chance that you could receive a defective radio, although that chance is small.

[Asa J]

Love the project. I feel bad for you though, this 'ible seems to have attracted all of the nitpicky grouchy old fogeys from the entire interwebs.
I haven't been keeping up with RC for awhile now so forgive my ignorance, but is it possible to mix for elevons via firmware?

[hivoltage]

Thanks! yeah you can create pretty much any kind of mix you want. The stock firmware supported a lot of different mixes but the new firmware supports a ton more. I haven't actually flown anything with this radio yet, but I have parts on the way for a flying wing style plane and will be mixing for elevons with this radio. Don't feel bad, in my experience from a few of my projects being posted on other blogs (lifehacker, gizmodo) the commenters here at instructables almost always have good (or at least constructive) things to say. Whenever my projects have been posted elsewhere commenters have been downright mean.

[TampaGeek]

The reviews of this radio at the Hobby King site aren't that impressive... have you had any of the problems they've listed? Darn thing seems very unreliable.

[mr.incredible]

Some of the early reviews are not even for the Turnigy 9x they were people speculating from their experience on the original Flysky version. I've had mine now for about 6 months. I still have the HK v2 firmware on it. It does everything my futaba does and then some. It is a very good radio out of the box, especially for the price. My only issues are with layout of the channel mapping on the receiver. It looks like the firmware upgrade will even fix those problems for me.

[hivoltage]

That seems to be a classic case of response bias, where only the people who felt very strongly about the product bother to write a review, and since the stock firmware isn't great you don't see to many people who feel strongly about this radio in a positive way. I think that most of the bad reviews were from people who got defective units, and most of those were due to corrupted firmware (HobbyKing flashes the V2 standard firmware on these in house) so following this instructable will fix any of that sort of issue. That said there is a chance that if you order this radio there will be some sort of physical defect since their quality control seems to be a bit lacking, but it doesn't seem to be as common as the reviews at the site suggest. Mine was in perfect condition, no disconnected cables or defective screens/pots/switches or anything. If you get a good one the hardware seems very solid and well built, high quality circuit boards and soldering inside for the most part, especially considering the price.

[mirakin]

I donno i would probably put the USBasp into the controller and change the usb plug to the mini usb so i could just toss a mini usb cord on it... flash my firmware and unplug and go leaving the USBasp in the unit all the time...

[dialup_prisoner]

You don't actually mention where get these updated firmwares. Of course I'm happy to google it myself but are there any sites you recommend for firmware, or RC radio hacking in general? Thanks for the great guide and photos.

[hivoltage]

This thread at rcgroups is a good place to read about the custom firmwares. each one has its own google code site if you want to download them. rcgroups is a great site for pretty much anything rc related, radios or otherwise. http://www.rcgroups.com/forums/showthread.php?t=1266162

[JoeStrout]

Thanks for the very useful instructable, and for the tip about the Turnigy 9X! My son and I are just starting to get into the hobby, and had a bit of sticker shock at HobbyTown last weekend... $54 for a 9-channel transmitter is a no-brainer, especially with your instructions on upgrading the firmware.

[pcaffeldt]

If you haven't already, you might consider checking out some cheap easy to build great flying planes here.

http://www.rcgroups.com/foamies-scratchbuilt-428/

Especially those planes sporting " KF " wings

http://www.rcgroups.com/forums/showthread.php?t=1117276

[achituv]

$53? where?

[hivoltage]

I got mine here:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8992

[astro_wanabe]

It's only ~$53 if you don't include HK's RIDICULOUS shipping!! The CHEAPEST shipping option is over $20, some options are over $30!! You should clearly state that the cost of this radio is closer to $75+ (depending on where you are, and if you would like to actually receive it sometime soon, it could be closer to $100)!

[XTL]

Some of us don't live in the US and so the shipping is much cheaper.
I think its fair to mention its price not including shipping. How urgently you want it is an extra factor.
Try to remember its a small world out there...

[hivoltage]

Even including the admittedly expensive shipping its still an amazing deal for what you get.

[dustinnewton]

Like he says, through Hobby King.

[pietzeekoe]

Hobbyking

[fidibiri]

Actually, he says "Hobby Town"

[pietzeekoe]

Nope

[fidibiri]

so, we both are right in a certain way: hivltage says $53 @ "Hobby King" and JoeStrout says $54 @ "Hobby Town" so.. I just made a mess of myself.. Thanks

[nerys]

Will this radio work with parzone bind and fly models? (are they all compatible with each other in the 2.4g realm?

also how does the turnigy perform compared to the spectrum radio's ?

[hivoltage]

pretty sure that this radio is only compatible with its own hobbyking branded 2.4ghz receivers. Theyre cheap though, only 8 or 9 dollars each and available at hobbyking.com. Theres a couple different ones there that are compatible. If you got a module for this radio you could make it compatible, but for whatever reason they made the stock module connect to the antenna through a hole in the back of the case so while its technically removable you will have to cut the wire and get a module with a port for its own antenna. This is my first and only "real" radio so I don't know how it compares with spectrum branded radios. The only thing about this radio is that you have to realize going in that by ordering it you are taking a bit of a risk because quality control on these is not great and shipping to return it to hobbyking costs more than the radio.

[66tbird]

Great instruct. thx. I've been needing a new tx and didn't want to pay another 9x03. A quick rcg search found a wealth of info.

[mr.incredible]

Thanks for the great write up. I've seen this several places but yours is the easiest to understand. I too have the Turnigy 9X radio. It is a good radio as it is. The firmware upgrade should make it great.

I think I will go a step farther and make a ribbon cable adapter to go between the USBasp and the new port on the radio. The loose wires is a little messy for my OCD.

[hivoltage]

yeah it was kind of a quick and dirty connector so I could try out the custom firmwares. If you got a 2x5 shrouded pin header you could install that instead of the ide connector piece and the usbasp would plug straight in. I didn't do that though because the program headers are like a direct line to the MCU and could damage it if any static electricity got in through the pins. for a really clean look you could permanently install the usbasp inside the Tx and just place a mini usb port in the battery compartment. I thought about doing that, but I wanted to be able to use the programmer for other things. Theyre really not very expensive though, cheap enough to permanently install inside if you wanted.