How to use your GWS/Smartech transmitter with FMS simulator - RC Groups
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Oct 20, 2003, 11:07 PM
Registered User

How to use your GWS/Smartech transmitter with FMS simulator


I've found a way to adapt the GWS or Smartech 4 channel transmitter to run on the FMS simulator.

I opened up the transmitter and probed with my scope until I found the digital signals that has the encoded positions of the sticks. The signal in the transmitter is a 5v TTL signal which is what the parallel port needs.

All that is needed is a 10k Ohm resistor (color code brown, black, red, gold or silver). The resistor is soldered to the encoded signal on the printed circuit board. A red wire is soldered to the other end of the resistor. A green wire is soldered to the ground of the transmitter.

The resistor is there to limit the current going to the PC. It is a prevent and damage to the transmitter or PC.

I've tried this and it works great. Note you still need the batteries in the transmitter to make this work. Also the transmitter will still be transmitting on the channel you selected. Maybe it is a good idea to remove the crystal?

Anyhow here are some pics:

This is a picture of the front of the transmitter (Duh!). Note the smartech transmitter is a rebranded GWS transmitter.
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Oct 20, 2003, 11:11 PM
Registered User
Here is the meat of the modifications:
Oct 20, 2003, 11:21 PM
Registered User
The picture describes the modifications. Once the are done and the two wires are hooked up to the parallel port you need to start FMS.

Go into the control menu, click on "parallel/serial IRQ-interface 32bit -VXD". Set the input to LPT1.

Then go into the calibrate menu and follow the procedure to calibrate the sticks.

Then set the channels in the following order from top to bottom
invert channels 4,3, and 2

Thats it.



NOTE: I've tried this and it works, but there are risks involved with anything in life. So if you break your transmitter or PC you do so at your own risk.
Oct 20, 2003, 11:39 PM
Registered User
Note: I have found that if you try and start FMS with the transmitter connected but not powered it brings the PC to a grinding halt. You need to turn on the transmitter to get things going. I'll have to investigate why this is the case.
Oct 24, 2003, 03:19 AM
Registered User
Have anyone gotten this to work?
Oct 24, 2003, 03:45 PM
Registered User

I've been running with this for a few days now. No problems other than you have to turn on the transmitter before you start the simulator and turn off the transmitter after you exit the simulator.

What is happening is when the transmitter is off it pulls pin 10 (ack) low indefinitely which causes the PC to go nuts. This can be fixed by adding a transistor and running +5v from the parallel port, but I can live with it the way it is now.

If anyone wants to do it "properly" I can show you how.

Nov 26, 2003, 09:34 PM
Registered User
Has anyone tried this with a WIN XP machine ?
Nov 29, 2003, 09:55 AM
Registered User
uuhmm, i followed your steps, connected it to my computer, scanned for hardware changes and it doesnt find it, and FMS isnt finding it , any ideas what could be causing this?
Nov 29, 2003, 10:25 AM
Registered User

I did the modification for my bother and we loaded the FMS on his machine and it did not work. When I used his transmitter on my machine I had no problems.

Looks like the FMS software that reads the joystick through the parrallel port isn't compatible with all hardware.

Nov 29, 2003, 02:37 PM
Registered User
oki, well, i spoke to a friend of mine, who opened one of his parrallel connectors, and on his the grey wire connected to pin ten and the black and white one to pin 18, so that is something you may want to look at on your brothers machine, i only have a parrael connector that cannot be opened, so i cant view mine, so i plan on trying to find one i can un-screw open to see if its that/
hope that helps
Nov 29, 2003, 05:45 PM
Registered User
I have a windows 2000 machine...does it work on win2k?? I did the mod and in the FMS software the parallel selection is grey...any idea why? I want this to work so bad as I need to learn faceing me flying
Nov 29, 2003, 05:46 PM
Registered User
I can't click resources or mapping that is what is grey and un-clickable
Nov 29, 2003, 07:14 PM
Registered User
Sorry guys, I'm running WIN98. Don't know about the others.

Nov 30, 2003, 01:12 PM
Houng-wen Lin
GWS4CEO's Avatar
Sorry to cause you so much inconvenience to modify out TX.

Next GWS TX will build in those circuit into PCB.

Dec 01, 2003, 08:46 PM
Registered User
ihug007's Avatar


Is it just me, or does GWS4CEO shamelessly spam pretty much every thread possible in this forum?

Does GWS have some deal going with

Just wondering...

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