using cat5 to wire front panel
I am wiring an mp3car into my `89 Ford Taurus. I already have the PC pretty much built, and wrote software in VB for the car, tested it in the house, using a num pad for control. When testing the mp3car in my passenger seat I found that my inverter made that annoying beep thing and wouldnt start if the pc turned on along with the car and inverter. However, if i give the inverter 4 or 5 seconds then turn on the pc, it works fine. I guess it probably has to do with the alternator in my car kicking in and charging up my capacitors. Anyway, i am making a little control box in my front panel, which will house the display, and a momentary power button that will be hooked into the power jumper of the ATX motherboard to turn on/off the system at my will. I wanted to mount an rj45 jack on the back of this little control box, so i could stow it or take it with me to prevent theft, and connect a cat5 into it when i bring it into the car, to make it easy. I've seen one other mp3car that does this.
I also wanted to run the stereo line audio from the PC soundcard thru the cat5, and have a little wire coming from my control box into the line-in jack on the front of my head unit. Here is the proposed wiring use in the cat5:
- shared ground brown-white
- +5v dc brown
for matrix orbital lcd2041:
- serial data in orange-white
- serial data out orange
for ATX power switch:
- power switch pin1 green-white
- power switch pin2 green
for line in to head unit:
- audio right ch. blue-white
- audio left ch. blue
I know many have put serial and 5vdc through a cat5, but has anyone tried sending line audio as well? My only concern is that the serial data and the audio will interfere. What do you think?
yeah you'll have extreme noise unless you use shielded cables...needa faraday cage on that mofo
I don't think power will be an issue as he is sending line level audio.Originally posted by Temujin:
<STRONG>My thought is that the wire might be such small gauge that it may not allow enough power, and your sound quailty might be crap. With the power and sound wires right by each other could cause some problems. Overall I think that your sound quality will be the worst problem, and not worth it.</STRONG>
However, there will be problems with noise. The reason twisted pair cat-5 works so sell is because of the twisted pairs. If you are sending audio, you will need to use 1 pair per channel...for example, right could be BW/B, left would be GW/G. Don't use a common ground and then send the audio through a different set of wires. Have you considered using a twisted pair cable with more pairs? Would solve your problems right there.
Player: Pentium 166MMX, Amptron 598LMR MB w/onboard Sound, Video, LAN, 10.2 Gig Fujitsu Laptop HD, Arise 865 DC-DC Converter, Lexan Case, Custom Software w/Voice Interface, MS Access Based Playlists
Car: 1986 Mazda RX-7 Turbo (highly modded), 1978 RX-7 Beater (Dead, parting out), 2001 Honda Insight
"If one more body-kitted, cut-spring-lowered, farty-exhausted Civic revs on me at an intersection, I swear I'm going to get out of my car and cram their ridiculous double-decker aluminium wing firmly up their rump."
I wired my computer to my television (across about 120ft) using good old CAT5 (2 strands), and ran 2 pairs for SVideo, 1 pair each for the 4 channels (sblive output). However before I did that, I used a single CAT5 with SVideo and just 3 wires for 2 speakers with a common ground and it wasn't bad at all.
Unfortunately in your car you will run into hideous problems with interferance, I'd recommend not going that route.
How far do you need to run it? I just used a normal RCA cheapo cable down the center of the car to the stereo (so away from all power lines) and it worked great.
[ 12-03-2001: Message edited by: Telek ]
IN DEVELOPMENT -- '96 Mustang, lilliput with PII/450 laptop, custom DC-DC power supply, 60GB; Garmin GPS; 802.11g; compact keyboard, small graphical LCDs, OBDII.
Yeah, i thought as much, i definitely don't want serial data and power getting into the audio, so i'll run RCAs separate from the other wires. The reason cat5 is really compelling to me is that I can make the front panel LCD removeable, as it will be in a small casing. Thus, i can simply unplug the rj45 from the lcd casing and take it with me. simple removable panel!
Remember, with Cat5, there's UTP (Unshielded, Twisted Pair) and STP (Shielded).
~m
PII 266, 512 MB RAM, 10 Gig, 36x CD-ROM, 16x DVD, DeLorme GPS, 5.6" LCD Screen, Dschmidt power controller, Keypower ATX DC-DC Supply, PowerAmp Macro controller, Dauphin mini-Kbd.
Sony Head Unit, Sony Unilink input selector, rear deck Kenwood 6x9's, stock door spkrs... All in my '96 Civic, of course :}
BC ROCKS!!!
Just use a cable with more pairs and a connector to match...Millions of possibilities out there at your local electronics shop...
Player: Pentium 166MMX, Amptron 598LMR MB w/onboard Sound, Video, LAN, 10.2 Gig Fujitsu Laptop HD, Arise 865 DC-DC Converter, Lexan Case, Custom Software w/Voice Interface, MS Access Based Playlists
Car: 1986 Mazda RX-7 Turbo (highly modded), 1978 RX-7 Beater (Dead, parting out), 2001 Honda Insight
"If one more body-kitted, cut-spring-lowered, farty-exhausted Civic revs on me at an intersection, I swear I'm going to get out of my car and cram their ridiculous double-decker aluminium wing firmly up their rump."
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