http://dx.com/p/12-pin-to-16-pin-obd...rs-10cm-115651
that's what i use.... kind of stubby, but it works.
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http://dx.com/p/12-pin-to-16-pin-obd...rs-10cm-115651
that's what i use.... kind of stubby, but it works.
Your best bet is here - http://aldlcable.com/sc/details.asp?item=daewoo
That way you know you have all the conductors that are needed. A lot of the OBD1 junk out there don't have wires on all the pins that are normally used.
the one i linked to has all 12 pins connected with seperate circuits.
Awesome post,thanks for the pic.
I think I might have what's needed onhand.
I needed a usb/ttl convertor for a subaru cable for a buddy and happened to order 3 since I figured they might come in handy (and they were like $3).
I also have an old OTC mindreader scantool that no longer likes to read OBDI.
So i'm gonna put this thing together and see if I can get it to talk to my 91 caprice.
If so,that means I don't need to buy one and can throw money at a burner.
mucho appreciado muchacho's.
http://i130.photobucket.com/albums/p...ps23003175.jpg
Okay,got as far as tinning all the connections to solder together and wanted to clarify something.
I still need to make the circuit using the transistor and resistors and then the tx/rx/grd goes to the usb/ttl adapter right?
I'm converting from ecm to serial with the transistor circuit,and the adaptor is converting from serial to usb correct?
I'm assuming the cable does not have that already built in,I have no idea how the otc talks to the ecm.
depends on your adapter. if it is TTL to USB converter, then no external components are needed.
what kind of chip is doing the work? with odd baud rates, only the FT232 chips seem to work reliably.
I'm guessing PL2303HX ?
Never mind,I think it says right in the description.Quote:
Description:
This PL2303HX USB to TTL converter module is a must for simple serial communication and allows you to upgrade the firmware of your router or ADSL modem.
Features:
Easy serial communication
Upgrade your router or ADSL modem's firmware
Simplify connections: RX to TX or TX to PX of an MCU. Then connect your GND, without the need for MAX232
GPS serial communication
Use as a serial debugging tool for the hyperterminal
Upgrade your hard disk's firmware
Upgrade various satellite receivers
Note:The color of Dupont Wire is random when we dispatch it.
Package includes:
1 x USB to TTL Module
1 x Dupont Wire
I had gathered that the transistor/resistor circuit was what everyone was calling max232?
with a 160 baud application, it might work, but i can't really guarantee it, i know the 2303 chip doesn't like 8192 baud at all.
MAX232 is an IC to help convert signals to and from RS232 specification.
A 7747 is 160 baud right?
That is what I need it for right now to get me by till one of your cables are ready
Yes 1227747 = 160 baud
HI. Great Thread. Is it possible to do anything with this one?
http://www.ebay.com/itm/380599351265...84.m1438.l2649
or this one:
http://www.ebay.com/itm/300771847336...84.m1438.l2649
the second would probably be able to be used after some workarounds(since it uses the FT232RL), but i really don't know bluetooth that well.
the first, i can't get a clear image of the ICs used, but if it's not a FT232R, don't expect it to work at GM OBD1 speeds.
So mine would be tx/rx tied to pin E for data,ground to ground/pin A and tie VcC/5V together on the convertor then right?
Then load up tunerpro and try to find a driver to work?
seems too simple,i'm forgetting something.
hope it works,if not need to order a cable from somewhere quick.
can someone smarter confirm?
Start with not connecting VCC to 5v. Normally that isn't needed, but you are using a different board so idk. If you have no lights at all when you are plugged into the USB only then do it, but if you get lights, then it is not needed.
You might need the 10K resistor between A - B to activate this output of the ECM.
1227747 = No 10k...
The FT232RL will only work if the TXD and RXD pins are inverted, since standard RS232 is already inverted from TTL. Fortunately FTDI included that fix in their programming utility. It's a no-brainer to download the free "FT_Prog" utility and set the TXD and RXD pins to "Inverted" status. http://www.ftdichip.com/Support/Utilities.htm#FT_Prog
That brings the polarity back in sync with the TTL versions. You can't directly tie the two pins together however. See this link for the wiring: http://www.firebirdnation.com/forums/topic/457761-make-an-obd1-cable-for-under-20/page__pid__866681#entry866681
i've built probably 30 cables without ever needing to do so? the first half used a FT232R and another converter IC to change TTL to RS232 to USB. this was before i knew better and just found TTL to USB via a FT232R.
The "another converter" flipped the polarity. Most involve the use of an RS232 IC or a couple of NPN transistors. The TTL-to-USB does not invert the signals to make it RS232 compatible. When I placed the FT232RL alone into use, both signals were upside down, giving complimentary data. Reprogramming fixed that. You may have used a special driver that took care of the inversion already. I have noticed that some companies supply the adapters with their own driver and their adapters will NOT work with the standard drivers from FTDI without the inversion.
i've always used and advocated using the standard drivers from ftdichip.com with no issue. it's possible that the boards i was buying were already running the modified program to account for this.
If you ever want to give that utility a try, the changes will not take effect until the unit is unplugged from the pc and plugged in again (rebooted). It seems that the internal hardware gets set at power-up time and not at program time.
Will this one work. http://www.superdroidrobots.com/shop...px?itemid=1173
Yes it should
looks like it uses the FT232BL, which is essentially an older version of the FT232RL. other than the circuit on the PCB required to use it being more complex, i don't see any reason why it wouldn't work.
the features added into the R version aren't really going to effect the end-user of an ALDL cable.Quote:
The FT232R is the latest device to be added to FTDI’s range of USB UART interface
Integrated Circuit Devices. The FT232R is a USB to serial UART interface with
optional clock generator output, and the new FTDIChip-ID™ security dongle
feature. In addition, asynchronous and synchronous bit bang interface modes are
available. USB to serial designs using the FT232R have been further simplified
by fully integrating the external EEPROM, clock circuit and USB resistors onto
the device.
The FT232R adds two new functions compared with its predecessors, effectively
making it a "3-in-1" chip for some application areas. The internally generated
clock (6MHz, 12MHz, 24MHz, and 48MHz) can be brought out of the device and used
to drive a microcontroller or external logic. A unique number (the FTDIChip-ID™)
is burnt into the device during manufacture and is readable over USB, thus
forming the basis of a security dongle which can be used to protect customer
application software from being copied.
Can one of you doublecheck my settings? I just completed a benchtop programming setup for '94-95 LT1s and I want to make sure I have all of the driver settings correct. I've done a successful datalog and two successful reads and the files appear identical. Before I try to write, can you verify the settings below are correct:
Bits per second: 9600 (8192 is not a selectable option).
Data bits: 8
Parity: None
Stop bits: 1
Flow Control: None
if you're having good reads(datastream or BINs), then writes should be just fine as well. those look like the default values, which are correct for this application.
Thank you Robert - I had success with multiple writes and reads. No more risk! I appreciate all of the work that went into this!
What is the best way to mount the board in a project box and which cable restraints are most rugged?
i friction-fit everything. the ALDL end, a 13/64 drill in the right place will clamp it in place nicely without risking the integrity of any of the wires. on the USB side... well, that will depend on the exact cable you're using and how you want it to be. i notch it out using a dremel.
i really need to get a small CNC setup, would cut down assembly time to ~20 minutes.
I use this one, case included. Construction time: about 5 minutes total for 12-pin, about 15 minutes total for 16-pin version.
http://www.ebay.com/itm/6pin-FTDI-FT...item5d3713fcc0
So does the board just float inside the box on the cables? The female usb socket is flush to the edge of the board, how do you stabilize or secure it to the box to allow cable install and removal?
Maybe I'm assuming a box larger than just bigger than the board. What are the dimensions of the box you recommend, or a source and part number.
3" X 2" X 1" box. you can find them at radioshack.
the way i build them, the squared off section of the male USB connector that mates to the FT232 board is rubber that compresses nicely. cut a hole slightly smaller than that squared section, press it in and it won't come out without taking the top off and pushing it back upwards.
Ah, so USB cable is permanently attached, and both cables are sandwiched by the lid in cut outs, now it makes sense. Thank you
more or less. 4 screws and one could swap out the cable with another should it become damaged.
Attachment 5131
You guys should know that you don't really have to fool with putting an adapter into a box or fitting the connectors to it. This FT232RL-based one in the photo is available for about $8-9 shipped. All you have to do is cut off the small 6-pin connector and the wires leaving only the white, green and black ones. Then splice them to your 12-pin/16-pin connector or pigtail. The 12-pin pigtail can be easily gotten for about $5-6 in the form of a 12-pin to 16-pin adapter (cut off the 16-pin one and throw it away). Splice the white and green to the brown (pin M) wire and splice the black ones together. Tape it up or use shrink tubing and you are done. This adapter has a translucent case so you can see the red and green lights (TX and RX).
i don't like the versions that have all of the circuit right at the USB connector.... my aldlcables.com version was like that, only lasted between 12 and 18 months before it completely failed. something up there failed and obviously couldn't be repaired and not look like a total hackjob.
the enclosure also allows for a nice place to mount the switch for the 10K resistor and relieves strain on the solder joints.
Sorry, I'm only an EE with 45 years experience with this kind of stuff. Won't bother you again.
i never said you were wrong, just that i have my preferences.
I just tested this adapter:
https://www.sparkfun.com/products/718
It's part of my Project Lab III kit (school), so I figured I'd give it a try in Tuner Pro.
At first I forgot about shorting the TX and RX pins, but after using an alligator clip positioned carefully, it passed the test.
I then connected it to an ECM on my test bench ('7730 running a stock ARUT MEMCAL $A1), connected as quickly as my Moates cable.
Just thought I'd pass it along.