IMPORTANT NOTICE: Today (April 30, 2015) I learned of a new version of the board that renders our kit difficult, if not impossible, to install (see updates below!) due to a change to the mounting holes (and possibly the screws). If your tx was purchased in 2015, double check that it has the three mounting holes highlighted in blue in this picture:
If you're missing the one on the left/middle, you have this changed board. I'm working on a solution.
[update May 1, 2015]: I have no way to confirm for sure, since I don't have this new board, but I don't think this is really a big deal. I did some testing with the "old" board, and our kit works just fine with only the 2 lower screws. Simply use the 3rd spacer (to provide support for that corner) but not the 3rd screw. The 2 remaining screws hold the board down well enough to work reliably. HOWEVER, there is some suggestion that the new board also uses larger screws (yet to be confirmed) and that our screws won't grip the plastic. If that is the case, you MAY need to find larger screws to match. We currently supply M2*12 screws (metric 2mm thread, 12mm length). You might try M2.5*12 or M3*12 but until I have a unit in hand, I can't personally confirm.
[update May 2, 2015]: I now have positive confirmation that the screws are larger on this new design, but that they will still fit through our board's existing holes. That is good news because it means our existing kit still works for the new 9x design, save for the screw mismatch. See how this helpful customer overcame this issue by repurposing two of the case screws. I'll call that a temporary fix, but really it should suffice. I'm hoping to confirm exactly what screw thread they are using so I can supply kits with both sets of screws. As stated before, I'm guessing they are either M2.5 or M3 screws, which you can probably pick up at a hobby store (12mm length). Hopefully someone can confirm what screws work soon. I have a radio on order but I have no way of knowing if it is the new design until it arrives. Sorry for any inconvenience this unforseen change causes anyone!
>>>> INSTALLATION INSTRUCTIONS <<<<
>>>> TROUBLESHOOTING TIPS <<<<
This add-on board was designed for the Flysky 2.4Ghz 9-channel radio transmitter model number FS-TH9B, commonly referred to as the "9x". It is also sold under various other re-branded model names and numbers, including (but not limited to): Flysky FS-TH9X, Eurgle 2.4Ghz, iMax 9x, and Turnigy 9x.
The 9x is an amazing value in the r/c aircraft world. You won't find a radio that costs so little that can do so much! However, it is not without its limitations. The primary complaint with the 9x radio is that the stock firmware is quite poor. Thankfully, some very clever people have written entirely new firmware that makes this cheap radio so powerful and flexible that it does things that units costing several hundreds of dollars more can't even dream of doing! Our add-on board lets you load that new firmware onto your radio easily... with no soldering, no cutting, and no specialized tools or skills are required! As a bonus, our kit also provides advanced support for the popular Hobby King 9x LED backlight system (some soldering required for this optional feature).
The primary feature of our board is that it gives you a full-time programmer installed in your radio that allows you to "flash" new improved firmware onto your radio whenever you want, just by plugging it into your PC via a common miniUSB cable (not included). If you get a generic programmer off eBay (or wherever), you have to solder 6 wires onto tiny pads on your radio's circuit board. While many people have done this successfully, there is a lot that can and does go wrong: incompatible programmer; soldering mistakes damaging the radio; frustrating trial and error; unsightly holes cut into your radio's case to make room for the clunky connector... and then you have to plug and unplug the programmer each time you want to update the radio! Our programmer stays in your radio and you simply use a familiar mini-USB cable to connect it to your computer. No soldering and no cutting whatsoever! And it is designed specifically for the 9x radio.
Advanced LED Backlight Support
The second feature of our board is the integrated LED backlight driver, which provides support circuitry for the popular - and inexpensive - HobbyKing LED backlight (not included). The circuitry adds the ability (once appropriate firmware has been flashed) to turn the backlight on and off by a variety of methods, and also provides full control over brightness (further firmware development required for brightness control). Without our circuit, the HobbyKing LED backlight is on full time and at full brightness only. As well, our constant-current driver provides steady power to the backlight over the full life of the battery so the light doesn't get progressively more dim as the battery drains, and it also ensures a longer life from the LEDs. You can puchase the backlight from HobbyKing in white, blue, and green. The use of the backlight with our board does require some modification to the backlight and also some soldering is involved for this feature. As of Revision 2.3, we now include a cable with a connector for making the LED connection a little easier.
Some important notes:
Rev 1: Green board. First prototype. Had primary power issue that had to be resolved to function (click here for fix). Had backlight power issue that resulted in too much power drawn from radio's CPU (click here for fix).
Rev 2: White board. Both Rev 1 issues resolved. Introduced possibility of radio rebooting when light turned off (click here for fix). No new features. Slight efficiency improvement with backlight. Some layout changes.
Rev 2.1: White board. Rev 2 issue resolved. No new features. Some layout changes. Different USB and EL connectors used (not compatible with previous revisions).
Rev 2.2: White board. EL backlight panel and circuit discontinued and replaced with support for LED backlight. Complete layout changes. Programmer power is now independent of radio power, therefore the radio must be powered on during programming.
Rev 2.3: White board. Now includes header and plug/wires for LED connection. Header for possible future use with TelemetrEZ added.
Rev 2.4[A]: White board. Shape of board changed to a rectangle. Board now uses 3 screws and 1 nylon support rather than 4 screws. Custom ISP programming cable included so the SP board can now be used as a generic USBasp for programming other devices. The main intent of this feature is to be able to update TelemetrEZ without having to open the case (but it can also be used as a programming interface with any AVR device's standard 10 pin ISP header). 2.4 is expected to be the final release. Some batches may be marked "2.4A". It is functionally identical to Rev 2.4. It is not to be considered newer or better. It just uses a slightly different LED backlight driver circuit due to component availability.