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Posted: Fri Jan 18, 2002 10:39 am
by babber
I intend to purchase an LK204-25 display (for a wired remote winamp controller)and connect switches to the keypad interface (rather than a keypad) for play, pause etc. The "parts" would be mounted in a project box and connected to a PC about 10m away. I would like to supply power and data up a single cable which will be suitably terminated each end. Would power line cause any sort of interference on the data lines in a single cable? Also, it would be convenient to send the audio signal up the cable as well (line level - not amplified) - would that work??
Any advice would be gratefully appreciated
Cheers
Babber
Posted: Fri Jan 18, 2002 11:49 am
by Henry
Well, you would require 4 lines for the basic stuff. RX, TX, +5V and ground. If you modify the cable you can put +5V into it and directly into pin 9 of the DB-9 connector. (you will require to do a solder jumper as well on the PCB)
As for the audio lines... why do you want them in the same cable?
Posted: Sat Jan 19, 2002 2:25 am
by relix
maybe he wants to build his own stereo? Cool idea!
Posted: Sat Jan 19, 2002 8:10 am
by babber
As for the audio lines... why do you want them in the same cable?
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To save having two cable runs. I have amplified speakers and I would put a 3.5mm jack socket on the wired remote to take audio to the amplified speakers placed nearby.
As for using +5v from the serial port, I didn't think this was a good idea? I would make a custom back plate taking serial from the motherboard and power from the psu.
Cheers
Babber
Posted: Sat Jan 19, 2002 9:50 pm
by Henry
Hmmm.. running everything you need in one wire should work... I would be only worried about noise...
"As for using +5v from the serial port, I didn't think this was a good idea? I would make a custom back plate taking serial from the motherboard and power from the psu. "
not sure what you mean here... by running the power cable into the DB-9 connector will save you on another cable. The LCD is capable of doing this, so why not use it
So making a serial + power cable all in one is a good idea, just make sure to have a good big ground wire.
_________________
Henry J.
Technical Support
Matrix Orbital
<font size=-1>[ This Message was edited by: Henry on 2002-01-19 21:50 ]</font>
Posted: Sun Jan 20, 2002 6:35 am
by babber
From the manual for the LK204-25:-
If the user intends to use pin 9 as the power source, the user must solder the 5 volt jumper point beside the DB9 connector. This is not necessarily a safe operation for a PC based application.
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As I am using a PC based application and I don't want to damage an expensive LCD, thought I should take power from the PSU. By the way, why isn't it necessarily a safe operaton?
Babber
Posted: Wed Jan 30, 2002 11:07 pm
by Newman
I am worried about the thickness of the LK204-25 in my application. Is there any way around using the DB-9 connector? I liked the alternative rs-232 option on the 204-25pc, yet again you find the thick DB-9 connector?