Help with USB to stereo wire makeup

I have a radio control transmitter that controls my r/c planes. I also have a Simulator program ( FMS ) that allows r/c people to train to fly before crashing too often! Ha !! The FMS simulator program works fine on my VISTA notebook computer with a Joystick.

Prior to using this newish computer, I had the same program running quite well on Windows XP. In spite of downloading additional driver files; adding a program called Smart Pro Po that was also supposed to help..I cannot get my Dell Inspiron

1525 notebook to recognize the Spektrum DX6 radio transmitter.

The input to the computer is accomplished by using the MICROPHONE port on the computer, and the TRAINER port on the transmitter.

What some people have told me I MIGHT NOW NEED is a USB to Serial male plug adapter cable. I don't mind buying one...but..so far nothing that anyone says will work has worked. I hate to send ten or fifteen bucks off; wait five or ten days, and then still not have the device work properly.

Since I have extra USB cables around, and I have a stereo plug sitting on the bench, is there a simple wiring diagram that someone could point me to.....that would result in a male stereo plug attached to a normal USB male fitting...to put into my computer? thanks vm Richg99

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richg99
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Well, if it's guarantees that you're wanting -- I can pretty much guarantee you that that particular hack won't work.

You don't just need something that has an audio connector in and a USB connector out. You need something that acts to the computer like a joystick, but uses the trainer-cord signal from your transmitter instead of an actual joystick. That's what the USB adapter does. It _doesn't_ just patch the wires -- it has a little microprocessor in it that emulates the joystick.

From what I know of things, if that USB adapter works on XP it'll work on Vista -- but I'm not guaranteeing anything.

(There's a reason I avoid Windows Vista...).

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Tim Wescott
Wescott Design Services
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Tim Wescott

Theoretically, the Smart Pro Po program is supposed to do that ( make it look like a joy stick). It supposedly converts a simple stereo male to male connecting cord to make the TX look like a joystick and to work.

My computer (Dell Inspiron 1525) seems to have a number of audio issues according to a Dell group on the 'net. Some owners have had to send their units back in. Normally, the audio is the very least of my concerns and uses...but..in this case...that item seems paramount. The only entry is the microphone port.

I have posted on the Dell "support group" to see what I can do about the audio issues without sending the unit back in. I am at my summer place, and the notebook is the ONLY computer that I have. Spending the summer waiting for Dell to fix an audio issue is not in the cards. In the Fall, I will have access to another computer, and the notebook could be easily sent away and not missed.

Soooooo... that leaves me with the USB to stereo potential option. If it can't be done, so be it...but...if it is a simple red wire to middle; black to largest and rearmost connector and yellow to the end connector....or whatever??? ..then I would like to try it. Rich

Reply to
richg99

When you talk about USB and baseband audio you're talking about entirely different worlds. Yes, they're both electrical so they orbit the same sun, but they're different worlds none the less.

Your transmitter's trainer cord is digital of a sort, but it is encoded in a format called "pulse position modulation", with square digital pulses whose spacing in time corresponds to the positions of the sticks. You're talking about a frame rate of 50-60Hz and pulse spacings of 1-2 milliseconds, which translates to frequencies in the low kHz.

USB is a way-fast digital mode. Depending on the flavor it can transmit bits at over 400 mega-bits/second, and involves frequencies up to

400MHz. It has some very elaborate signaling schemes embedded in it to make it work as reliably as it does.

The very best thing that can happen if you try connecting your transmitter directly to your USB wires would be if neither your transmitter nor your computer were harmed. The computer certainly wouldn't be able to make sense of the very non-USB signals coming to it from the transmitter.

Stereo audio is a slow analog signal. The voltage is a direct analog of the motion of the air when you hear sound. You won't see significant energy above 20kHz, or below 20Hz.

The only way that your Smart Pro Po program could work would be if it hijacks the normal microphone input from the sound card, processes it to figure out the signal from the transmitter, then presents it to the innards of Vista as if it were some oddball custom joystick driver. Speaking as someone who has written drivers for DOS and has avoided PC programming since then, the possibilities for things going wrong are absolutely boundless (which is why I avoid PC driver programming). The sound card has to match the program's preconceptions, the program has to match your peculiar installation of Vista's preconceptions (and _every_ installation of Windows is peculiar), and the moon has to be in the right phase. If this is on a machine that already has known problems with the sound card then -- good luck!!

The way that the USB joystick interfaces work, as I said before, is to exactly emulate a USB joystick. Unlike Windows drivers, this is not rocket science. There's an itty bitty computer sitting between your transmitter and your USB port, and it's only job is to make that USB port think that it's a regular old joystick. There's no soundcard cleverness being played, there's no Windows driver cleverness being played, there's just a device that knows exactly how to look like a joystick, looking like a joystick. Again speaking as an old DOS driver writer and current writer of embedded software, this is a much more likely way to make things work.

So the task of making the soundcard audio not only look like a joystick to Vista, but to correctly translate your transmitter's signals, is like trying to weld 100 riding lawn mowers together to make a truck. It's theoretically possible, but there's lots of really stupid things that can go wrong.

On the other hand, the task of interfacing between your transmitter's trainer port and a USB port is like putting a Dodge engine into a Chevy. Some may find it a peculiar thing to do, but it's a project that's a heck of a lot more straightforward than those 100 lawnmowers and the arc welder.

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Tim Wescott
Wescott Design Services
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Tim Wescott

So I will buy a cable then..just thought I'd save some time. thanks rich

Reply to
richg99

ch

Do yourself a favor and go back to XP

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arydberg

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