What’s inside the chinese ELM327 USB


I had to buy a few ELM327 with USB cable for different project. I have no use for USB cable as it is in the module, but I hope there is UART and kinda liked the idea of just stripping out the USB cable and replacing with the other one without changing the case.

This is it:

And without the label:

Under the label.

Screw holes, nice. But no screws inside 🙁 Just melted PCV. Well, let’s open it anyway, maybe I am missing something:

Opening the case the hard way.

With a bit of force it worked. Here is what’s inside:


Small chip (8 legs, one floating) is the NV342-0 which is CAN transceiver (Vsplit is N/C): http://www.onsemi.com/pub/Collateral/NCV7342-D.PDF

In the second picture a soldered on the top board has 12kHz oscilator and PL-2303HX – UART to USB converter (Prolific one).

The main controller is probably under the black blob in the middle. And the cable cannot be disconnected without desoldering.

I am actually really surprised with this, it seems to be multi-layer PCB (more than two layers for sure) with a BGA chip. Quite well engineered, maybe not so well done (handmade :D), but still, better than I predicted for the price.

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