OBD2-Adapter | Posts 32+

Since I didn't have a plug, I had to insert the bare wires... The ground is connected to the capacitor, but not the 12 volts. I also don't understand where those 12 volts are supposed to be coming from. On the PDF schematic, it's directly connected to 12V, but in the picture of Jeff Noxon's circuit board, it doesn't seem to be!

Hello,

"In my opinion, it should also fit on the PCB layout, since the connection from the positive terminal of C1 goes directly to the 9-pin connector?"
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Best regards, Rainer.http://www.dieselschrauber.de/Temp/pcb-b1.jpg{MARKER}

Okay, I can't understand what's going on. I strictly followed the wiring diagram, and I assembled the 'layout' using stranded wire to save space. The wiring diagram is absolutely correct. Both interfaces worked perfectly right from the start and still do to this day.

'Hey, you should carefully double-check your wiring against the schematic diagram. There's definitely a mistake or a misaligned component somewhere. And of course, remove the components as much as possible beforehand (I've socketed the optocouplers and transistors).'

Are all the resistors okay? Did you accidentally install a 100 ohm resistor instead of a 10k ohm resistor?

Are the optocouplers correctly connected?

CU Gremlin.

Yes, and if you are using the BC546 or 547 transistors, be aware that the pinout is different (the collector and emitter pins are swapped). If not, then BANG, and you'll need new transistors.

The flattened side should face away from the optocouplers.

Sorry, I couldn't access the internet for a while because my DSL connection stopped working due to the flooding.

@ Rainer: I really missed that spot you circled, or I didn't take it seriously enough. Now my capacitor has 12V, but the adapter still isn't being recognized.

Probably, after all the experimenting, some component might be broken now. But I don't feel like starting all over again. I've had enough.

I definitely want to thank everyone who tried to help me. Thanks, guys!!!

Best regards.
David.