Topic: Make Your Own Rs232 To Ttl Converter (Read 80 times)

toxickiwi · « **on:** January 05, 2009, 07:47:00 AM »

People keep asking the same question...
"Where can I find an easy to follow schematic so I can build an RS232 to TTL Converter?"

These 2 images should make building and using an RS232 to TTL converter much easier as I've removed all unnessecary data lines from the schematic.

(IMG:http://i92.photobucket.com/albums/l24/toxickiwi/DG-16D2SRS232toTTLConverter.gif)

(IMG:http://i92.photobucket.com/albums/l24/toxickiwi/DG-16D2STxFIX.jpg)

You need...

1x Maxim MAX232CPE chip
1x 16pin IC socket
1x small prototype board on which to build your converter
4x 1uF 16V capacitors
1x DB9 socket
Hook-Up wire

Make the "RS232 to TTL converter" (+) circuit taking care to get polarity correct for the capacitor
Make the "RS232 to TTL converter" GND circuit taking care to get polarity correct for the capacitor
Add the C1 and C2 capacitors taking care to get polarity correct
Connect T1.Out to Pin 3 of the DB9 socket.
Connect LiteOn Tx point to T1.In of the Max232 chip.
Rebuild the Tx circuit on the LiteOn PCB or use the "Tx via" as shown in lower image
Connect (+) of "RS232 to TTL converter" to 3.3v (+) LiteOn circuit as shown in lower image
Connect GND of "RS232 to TTL converter" to GND on LiteOn circuit board as shown in lower image

Cheers

xplicit582 · « **Reply #1 on:** January 05, 2009, 04:51:00 PM »

QUOTE(toxickiwi @ Jan 5 2009, 10:23 AM)

Connect T1.Out to Pin 3 of the DB9 socket.

Shouldn't it be pin 2?

STICKY_BUD · « **Reply #2 on:** January 05, 2009, 06:16:00 PM »

you need to fix your picture diagrams because the max232 requires 5v only and you are showing 3.3v, but the max3232 will accept 3-5v...

pogi1100 · « **Reply #3 on:** January 05, 2009, 08:18:00 PM »

UMMMMMM.....
It's supposed to be TTL to RS232 not the other way around... well... i guess it's the same...

This post has been edited by pogi1100: Jan 6 2009, 04:19 AM

toxickiwi · « **Reply #4 on:** January 05, 2009, 10:33:00 PM »

RE.. xplicit582 Posted Today, 01:27 AM

I said.. "Connect T1.Out to Pin 3 of the DB9 socket".

You replied... Shouldn't it be pin 2?

Correct. I mixed it up when redrawing the schematic below so the pin numbers relate to their actual position on the chip. I'll try to edit it and reload to PhotoBucket.

(IMG:http://i92.photobucket.com/albums/l24/toxickiwi/MyTTLtoRS232Schematic.gif)

Quote

STICKY_BUD     Posted Today, 02:52 AM
   you need to fix your picture diagrams because the max232 requires 5v only and you are showing 3.3v, but the max3232 will accept 3-5v...
Quote

The MAXIM MAX232CPE works fine with upto 5v (in our case 3.3v) which is supplied by either your 360 motherboard or a Connectivity Kit. If it didn't work I would have got no or incorrect keys and then the spoofed firmware I made and loaded to my Samsung MS25 would NOT have read backups when fitted to the LiteOn 360 console.

pogi1100     Posted Today, 04:54 AM
   UMMMMMM.....
It's supposed to be TTL to RS232 not the other way around... well... i guess it's the same...
Quote

Yes your right because I have removed the lines that convert RS232 to TTL.

This post has been edited by toxickiwi: Jan 6 2009, 06:35 AM

toxickiwi · « **Reply #5 on:** January 05, 2009, 11:17:00 PM »

CORRECTED IMAGE SHOWING PINOUT FOR THE DB9 PLUG.
USE PIN 2 & PIN 5.
DO NOT USE PIN 3.

(IMG:http://i92.photobucket.com/albums/l24/toxickiwi/EditedTTLtoRS232AdapterSchematic.gif)

Cheers

warbeast · « **Reply #6 on:** January 06, 2009, 07:27:00 AM »

a simple one that only needs wires no capacitors using the max233 i wired mine up then just wraped it up in tape

(IMG:http://img266.imageshack.us/img266/4378/max233a1wr7.jpg)

This post has been edited by warbeast: Jan 6 2009, 03:31 PM

pogi1100 · « **Reply #7 on:** January 08, 2009, 05:51:00 PM »

You will need to solder R708 if you're going to flash the lite-on drive...

warbeast · « **Reply #8 on:** January 08, 2009, 07:18:00 PM »

no you dont 707 is tx input 708 is rx output you only need 707 thats why we also need sata connected

johnny13oi · « **Reply #9 on:** January 16, 2009, 01:59:00 PM »

I made this circuit and still get invalid keys of 00000000000000000000's and can't get it to work. Are you sure that the capacitors are 1uF and not .1uF?

Leftfield_2k9 · « **Reply #10 on:** December 09, 2009, 11:41:00 AM »

QUOTE(johnny13oi @ Jan 16 2009, 10:59 PM)

I made this circuit and still get invalid keys of 00000000000000000000's and can't get it to work. Are you sure that the capacitors are 1uF and not .1uF?

Then you have probably connected it up wrong or you have damaged the IC with too much heat!
I can confirm that the circuit above worked 100%, I used it to extract my key from a Liteon 74850C (A0A1) which I then spoofed onto a Sammy MS28 drive, worked a treat.
A massive thanks to the OP, cheers dude you saved me some £$£ which is much appreciated! :-)

Below is a pic of the extractor I build using the above guide.

IPB Image

ttldummy101 · « **Reply #11 on:** January 30, 2010, 06:45:00 AM »

ok so i need some help, I pulled a st232c chip out of a board , but hers the issue im trying to understand , following the leads of this chip it had a set of capctoir that looked like this they are .01uf (IMG:http://i863.photobucket.com/albums/ab199/photodummy101/caps1.jpg)

know having that said , my question would be is it possible to use these capacitors , also they do not have any polarity .. so im not sure , but i have seen TTL built with this cap on the board.. my chip is a clone of max232c here's what it looks like (IMG:http://i863.photobucket.com/albums/ab199/photodummy101/232cd.jpg)

im looking to wire my rs232 to ttl like the one Leftfield_2k9 maid(IMG:http://i863.photobucket.com/albums/ab199/photodummy101/dscf21347k.jpg).. if someone can help on this, I thank you in advance very much................ the only thing is i need the rx tx gnd and + cables ..
i see only the TX cable and GND

Heres a Picture of what i mean there got to be a way to make this with out a board and using those caps
(IMG:http://i863.photobucket.com/albums/ab199/photodummy101/001.jpg)
thanks again

This post has been edited by ttldummy101: Jan 30 2010, 03:24 PM

iateshaggy · « **Reply #12 on:** January 30, 2010, 08:28:00 AM »

this is why i tell people to by a usb xtractor or use the mra method to get your firmware. homemade probes really need to die.

Tjark · « **Reply #13 on:** February 04, 2010, 08:46:00 AM »

The capacitors you have are not polarized so it does not matter which way around you place them. Just as long as the capacitance (nF) value and the working voltage (16 or more Volt) are ok. In my opinion the ICL3221 is a better chip than the MAX232. It can use smaller capacitors, it is lower priced and you can operate it from 3.0 to 5.5 V.
Nice wiring you did, I also used to work like that earlier on. For that reason we designed a ready made RS232-TTL converter.
If you are interested, check http://www.tildesign...r-2010107101P2N
Datasheet of the ICL3221 and schematic of the converter can be downloaded from that page.

Author Topic: Make Your Own Rs232 To Ttl Converter (Read 80 times)