Print

[eyepartie]

I am aware of the Iogear Guc232a cable contains an rs232 transciever chip (among many other components) a cable which I happen to have lying around. Is it possible to use the +/- wires of the USB end as Txd/Rxd (or vice-versa) for retrieving the key from a lite-on dvd drive and if so, does + correspond to Txd and - to Rxd (or vice versa); would there be any other moddifications to this cable anyone recommends; am I forced to completely de-solder the rs232 chip out of the entire GUC232a board and re-solder according to other guides, or is there an easier/alternative approach (solder-related, not going to buy any maximus or other presoldered device, no fun :-)?

It seems ideal since a usb cable typically consists of 4 wires: 2 of them +/- and the other two Gnd and power (5v, 3v, etc); the only difference that can be seen between a serial cable and a usb cable is of course +/-  and Txd/Rxd, respectfully. Any comments and/or questions are appreciable. Thank you.

This post has been edited by eyepartie: Nov 30 2008, 07:28 AM

[yaywoop]

check out the datasheet for the trancever chip. you should be able to tap in to the TTL level serial on the other side of the chip. you might have to lift the Rx pin on the trancever chip...
or you could just make an inverting buffer using a transistor (like in my tutorial http://forums.xbox-scene.com/index.php?showtopic=668247 ) and leave the usb converter intact.

and usb uses a much more complex protocol than rs232 serial. you can't just listen in on raw data coming in the usb port, that's why you need a serial converter chip. otherwise it could just be done  by using a different driver
also USB uses Differential signaling and rs232 serial uses Single ended signaling...

[eyepartie]

QUOTE(yaywoop @ Nov 30 2008, 09:17 AM)

check out the datasheet for the trancever chip. you should be able to tap in to the TTL level serial on the other side of the chip. you might have to lift the Rx pin on the trancever chip...
or you could just make an inverting buffer using a transistor (like in my tutorial http://forums.xbox-scene.com/index.php?showtopic=668247 ) and leave the usb converter intact.

and usb uses a much more complex protocol than rs232 serial. you can't just listen in on raw data coming in the usb port, that's why you need a serial converter chip. otherwise it could just be done  by using a different driver
also USB uses Differential signaling and rs232 serial uses Single ended signaling...

Ok Im going to de-solder the tranceiver chip and try to use it (I hate that converter, its ugly and useless). Then if that doesn't work, I will try ur method. Much abliged! (right spelling?) Good information. Great reply (now I feel like I'm entering user feedback on ebay, lol no more rum for me)

This post has been edited by eyepartie: Dec 7 2008, 08:52 AM

[eyepartie]

Yaywoop I found a datasheet for the guc232a transceiver chip I was telling you about. The direct link is: http://www.analog.com/en/interface/transce...ts/product.html . It appears to be EXTREMELY similar to MAX3232 in that I see EVERY SINGLE pinout (such as t1out/t2in/r1out/r2in, etc.) The only difference (besides position of pins) is that my chip has 28 pins whereas max3232 has I think around 16/18. What I'm getting at is, I found a rs232 circuit link http://forums.xbox-scene.com/index.php?sho...68247&st=15 (2nd post down from the top) that involves 5 capacitors 0.1 uf. Can I do the EXACT same thing with my chip as long as I stick with the same pins (same T1 out/t1 in, etc. etc.)? I hope this makes sense. I really appreciate any/all further help. Thanks again.

QUOTE(yaywoop @ Nov 30 2008, 09:17 AM)

check out the datasheet for the trancever chip. you should be able to tap in to the TTL level serial on the other side of the chip. you might have to lift the Rx pin on the trancever chip...
or you could just make an inverting buffer using a transistor (like in my tutorial http://forums.xbox-scene.com/index.php?showtopic=668247 ) and leave the usb converter intact.

and usb uses a much more complex protocol than rs232 serial. you can't just listen in on raw data coming in the usb port, that's why you need a serial converter chip. otherwise it could just be done  by using a different driver
also USB uses Differential signaling and rs232 serial uses Single ended signaling...

This post has been edited by eyepartie: Yesterday, 09:56 AM

[yaywoop]

QUOTE(eyepartie @ Dec 15 2008, 07:55 PM)

Yaywoop I found a datasheet for the guc232a transceiver chip I was telling you about. The direct link is: http://www.analog.com/en/interface/transce...ts/product.html . It appears to be EXTREMELY similar to MAX3232 in that I see EVERY SINGLE pinout (such as t1out/t2in/r1out/r2in, etc.) The only difference (besides position of pins) is that my chip has 28 pins whereas max3232 has I think around 16/18. What I'm getting at is, I found a rs232 circuit link http://forums.xbox-scene.com/index.php?sho...68247&st=15 (2nd post down from the top) that involves 5 capacitors 0.1 uf. Can I do the EXACT same thing with my chip as long as I stick with the same pins (same T1 out/t1 in, etc. etc.)? I hope this makes sense. I really appreciate any/all further help. Thanks again.

so do you want to use the rs232 level converter out of your usb-rs232 adapter with the com port of your pc?
uhh why?
why not use the usb adapter part, get rid of the level converter, solder a wire to where the tx pin of the level converter was, and you have your adapter
because the adapter looks like it uses TTL signaling between the usb chip and the level converter (otherwise it wouldn't need a level converter)
if you can post a link to a decent photo of the board i might be able to tell you which pin to solder to

[eyepartie]

QUOTE(yaywoop @ Dec 15 2008, 11:11 AM)

so do you want to use the rs232 level converter out of your usb-rs232 adapter with the com port of your pc?
uhh why?
why not use the usb adapter part, get rid of the level converter, solder a wire to where the tx pin of the level converter was, and you have your adapter
because the adapter looks like it uses TTL signaling between the usb chip and the level converter (otherwise it wouldn't need a level converter)
if you can post a link to a decent photo of the board i might be able to tell you which pin to solder to

Well first of all Im not really sure what you mean by the "level converter", and secondly, I had to 'chizzle' the whole board out of it's plastic encasing (its like the plastic was embedded around the circuit, a real pain to get out). I could send you the picture, but all you'll see is 2 chips (the usb IC and the more important ADM213 IC) with no decent circuit board because of all the chizzling. So, Im forced to de-solder which is what im doing right now. Even though Id really like to further understand what you mean by the suggested shorter approach, is it still possible to solder the db9 to the transceiver chip in the same similar way as the max3232 chip? Your help is always appreciated!!!!! Thanks again.

This post has been edited by eyepartie: Today, 02:58 AM

[yaywoop]

you are better off ordering a free sample of the max3232.
or just do the free approach in my sig, a lot easier.

if you leave everything on your adapter intact, you can use my tutorial on that if you want.

what i was trying to say in my last post is that the adapter has a usb to serial converter, which uses TTL voltage (0 to 3.3V) just like the liteon drive, so if you can tap in to that, you can just connect it directly to the Tx in the liteon drive and it will work, through usb.