FRSKy Mod - Using Mikes Guide

[Rob Thomson]

Hi All,

I am modding a radio for the first time using Mikes method as outlined on this pdf:

http://er9x.googlecode.com/svn/trunk/do ... ryMods.pdf

Now. The instructions say the following:

To use the two pins from the DJT module, they need to be isolated
from the board. Pin 5, labelled DJT Tx in the picture, only needed a single cut on the visible side of
the board, it may be seen just by the end of the orange wire. Pin 2, labelled DJT Rx in the picture,
needed one cut on the visible side, and two on the side towards the module. The board will, of
course, need to be unscrewed to get at the other side

No problem.

So..

Cut on Pin5 done.
Cut on Pin2 done (visible side)

Unscrew.. turn the board over..

Where do the cuts get made? The board has a lovely black covering on it!!

Any ideas?

Rob

[MikeB]

Is the black just a thick paint layer or is it some sort of thin extra material?
Mike.

[Rob Thomson]

Right.

Issue is that the back board is covered in paint. (maybe something new from the factory)

I solved my problems by re-thinking your schematics slightly.

As can be seen in this image, I simply used the old antenna pins! This meant that I only needed to cut the track on the visible side of the board.

I did need to move the one line in the module itself, but this was no big issue.

Rob

[jhsa]

I've posted a picture some time ago on RCG of when I've cutted the tracks under the black material.. Just cut in front of the pin and check with the multimeter that is not connected anymore. I think it's connected to ground?? can't remember..
Found it..
João

[GrootWitbaas]

Doing this right now, reserving this post for pictures to show.

Ok so I removed the pins from the board, cleaned of the black stuff, and took some pictures so that those who want to do the mod can have a look where the tracks run, and cut them without having to remove the black coat. They say a picture tells a thousand words so I let them talk. Please no comments on my soldering ....or the board not being clean on all pictures. I used clear nail polish to reseal the tracks afterwards.

removed the plastic pin holders

Cleaned the black coating

Cut the tracks on both sides

Every thing back in place. From this picture it is easy to see where to cut without having to remove the coating. You can cut right next to the plastic on both sides.

And the top side, also showing my version of the ppm resistor fix

The End.

[Rob Thomson]

Interesting.

The last mod I did used the bottom two pins - and I did not cut the underside track - yet all works ok.

I also used my meter to check for any circuits, and do not get any when probing between gnd and the pin!

Strange.

Rob

[GrootWitbaas]

Maybe you have the knockoff of the cheap knockoff because your other board was also different ....or maybe you have the original and we all have the knockoff's.

[ShowMaster]

FYI FlySky /Frsky module interchangeability concern.
If you want to reuse the Turnigy or FlySky original module you'll have to do the same pin isolation on the stock modules after you do the txd rxd mods to the TX per Mike's great circuit mod. The pin we use on the modified DJT for RXD out, TXD into the 9x is grounded in the stock modules. I'm not sure we want and pins from the stock modules connecting or TX rs232 converet to ground. I opened up my FlySky stock module and cut the trace around the second pin from the top free from the internal ground plane. I've tested my 9X with both modules now and they all work and there has been no damage noted. Worth looking into if you plane to reuse the stock module as well as the Frsky DJT after the telemetry updates.
SM