Which frsky mod

[bill516]

I stuck with which frsky route to go down, I've read all the how to's and I'm more confused than ever. Could someone explain the various mods and what you need to complete them i.e what hardware to buy.

If its any help I had a little problem yesterday where my antennae cable broke at the solder joint so I took the opportunity to move the antennae from the Tx case to the module case. I have also soldered two wires to pins 41 and 42 when I did the Haptic mod in prep for the resistors but now I see that you can just cut two traces and solder to the smd resisitors.

[Crucial]

Either you buy the DJT module and plug it in to the back of the radio or buy the DHT DIY module and install it internal to the radio. Once you decide which version you want to go with you then have to figure out what you need to complete it.

http://www.alofthobbies.com/jr-transmit ... odule.html
http://www.alofthobbies.com/diy-telemetry-module.html

Have you decided on which route you would like to take?

[bill516]

No I havnt decided that is part of the problem, which way to go. I know one way involves adding wires which I have already done and there is the plug in module that does not require any mods to the TX, or does it. In the pdf's there is talk about frsky light or something or is that just part of one of the two options I have mentioned above.

I am thinking that maybe the module maybe the best option as I had to reattach the aerial lead so I re-routed it so I can just unplug it if I need. Or could I install the DIY option in a module case and use it like that unplug if I need to/want to go back to the 9x Rx.

[jhsa]

Well, I think you are very confused about all this..
Supposing you want the telemetry on the 9x LCD display.
You can go two ways:

1. You get the frsky DJT module. This is the one that fits in the back of the radio. You will have to mod also the module and the 9x back PCB. If you go with this one, you can later remove it and plug the original Turnigy module.
Attention: you will have to cut some traces on this Turnigy module as well, to isolate the pins that the frsky module uses for the telemetry..
2. you get the frsky DHT, which is the DIY module and it has to be soldered inside the radio.

Now, for the telemetry mod you have two options:

1. You do the mod using a level converter ( the frsky upgrade lite or other level converter)
2. You do the mod without the level converter and follow Kilrah's guide.

For both telemetry mod options you need the two little wires soldered to pins 41 and 42 of the Atmega, which you say you already did..
If that is true, you already done the most difficult part of the mod. Well done

Those two wires are to re-route two of the switches (THR and AIL) to those pins, and yes if you cut the traces (and I'm supposing you know which ones to cut) you can then solder the wires to the resistors..

João

[Crucial]

It sounds like you are well on your way to getting the mod figured out.

To explain the frsky lite use a little further. The frsky module telemetry data talks with one level of signal and the 9x talks with a different level. The frsky lite makes it so that the frsky module telemetry signal and radio can talk to each other. As Joao already explained this is needed no matter which version frsky module you use, UNLESS you use the other(kilrah) method of connecting the telemetry wires. Info for that here. viewtopic.php?f=23&t=430

[bill516]

I think its sinking in, frsky and telemetry are two different beasts. You can have frsky without telemetry but if you want telemetry you need a level convertor or the Kilrah method. Just had a quick look on HK and I think its going to be the DJT option, I rather like the idea of being able to revert back in case something happens and it means I havnt wasted money in the 9x Rx's I've got.

[jhsa]

exactly.. you can just place the frsky DJT module in the back of the tx, or the DHT inside and solder the PPM, VCC and GND wires and use er9x non telemetry version of the firmware.. you can still have the RSSI alarm from the frsky module..
But if you want telemetry on the 9x's screen you must do the mods

[bill516]

Will you just look at that between you and Crucial you've managed to un-confuse a dinosaur. Could the DHT be fitted in a case and made removable like the DJT ?, like to keep my option and whats in stock open. Looks like I know what I want for my birthday.

[jhsa]

I don't really know if that would fit in a case.. but must be a JR type case.. I think someone did that here, but who?
Maybe Kilrah but not sure.. I'm sure I've seen a picture somewhere.
But you would have to buy a case too..

João.

[gohsthb]

There is still the option of putting the DHT in the case. For me I installed a DPDT switch. With the switch I can select the internal module (DHT) or to use the module plugged into the outside bay. What I did was cut the Vcc and PPM tracks to the module bay pins. I connected the center of the switch to the cpu side of the cut. Then one side of the switch to the module bay pins, finally the other side of the switch directly to the DHT. This will switch the power and ppm signal lines between modules.
-Gohst

[tman]

There is still the option of putting the DHT in the case. For me I installed a DPDT switch. With the switch I can select the internal module (DHT) or to use the module plugged into the outside bay. What I did was cut the Vcc and PPM tracks to the module bay pins. I connected the center of the switch to the cpu side of the cut. Then one side of the switch to the module bay pins, finally the other side of the switch directly to the DHT. This will switch the power and ppm signal lines between modules.
-Gohst

Why not just leave it as is and pop the second module in? And maybe unscrew first antenna if worried about losing signal power into it?

[jhsa]

don't power the 2,4Ghz modules without antenna under the risk of damaging them..