Teardown of Automatic OBD dongle
Tags: obd, teardown
Published: 2020-12-23 01:27:36

# Background

In January of 2019, I purchased an Automatic® car tracker. It was a simple piece of hardware that would connect to your car's on-board diagnostics (OBD) port, and was equipped with Bluetooth and LTE. I bought it mainly to be able to log my trips, as I wanted to get a picture on exactly how much I was driving.

# Fast forward

This year, the company announced they were going out of business, and would shut down the service immediately.

https://www.theverge.com/2020/5/1/21244295/automatic-labs-vehicle-tracking-service-covid-19-pandemic-rebate-may-28th

# Motivation

Once the service was shut down, I realized my $99 dongle basically became a paperweight. Or did it?

After all, I still had the hardware, I just don't have the infrastructure supporting it. 

I wanted to see if there was a way to salvage this part and hopefully turn it into something useful again.

# Goal

Before I can figure out a way to use this dongle, I first have to take it apart and figure out exactly what parts on it and how I can try to connect to it.

That's what *this post* exactly is -- a teardown. My goal in publishing this is that others who have this dongle can get the information they need on the part without having to physically open their unit.

# Pieces

## Connector

To start, let's examine the (back) of the OBD connector.

![obd-connector](https://i.imgur.com/T4Dqi5k.jpg)


Remember that you're looking at this from the back view so:

* Pin 1 is at the top right, Pin 8 at the top left
* Pin 16 at the bottom right, Pin 9 at the bottom left

You'll also notice that there's 2 empty pins: pin #9 and #13. 

If you search for the OBD pinout diagram online, you'll see that these 2 pins are labelled as 'vendor's choice' or something to that effect. 

!["OBD pinout"](https://lh3.googleusercontent.com/proxy/RhZW1a2r2GjLig8-M2-JUsRHgU7adT2H-l-BIFWbluksQEAPsNcUUMj_pKRnsPAP4OwB3FVxkqaMP_2JMyEPhEwJXxzwf-LmzhiCy9xOaGlS0kVuxnjK5bDm69cs86hAYENqgOn87BDE9yggg2e8SG-hyQ)

https://en.wikipedia.org/wiki/On-board_diagnostics#OBD-II_diagnostic_connector

## Board

The OBD module itself has arranged horizontally, in 3 parts. Each of the images of the board provided has a number on it -- so when fully assembled, if you look at the board from the side:

```
1 < - top
6 < - bottom
5 < - top
3 < - bottom
4 < - top
2 < - bottom
```

(Just look at the pictures below and I promise it'll all make sense)

### Bottom layer

Here's the bottom view of the bottom layer.

![1-bottom](https://i.imgur.com/uJF7FMI.jpg)

Here's the top view of the bottom layer.

![1-top](https://i.imgur.com/RhU0axv.jpg)

We see that this PCB holds the "OBD sim board" on one side, and what looks to be the wireless radio on the other side.

We can lookup the IMEI given, on any number of IMEI databases to get some more information about it: https://www.imei.info/?imei=354421076447994

![imei-lookup](https://i.imgur.com/wNkVUOH.png)

The IMEI lookup tells us the manufacturer is U-BLOX  and the model is "SARA-U260", so armed with this information we can consult the datasheet to learn more about it.

https://www.digchip.com/datasheets/download_datasheet.php?id=8846450&part-number=SARA-U260-00S

It looks to be a standard, run-of-the-mill HSPA/GSM modem, not unlike what you would find in cell phones several years ago. The antenna connectors - ANT 801 and 802 - are housed on the other side of the board.

### Middle layer

Here's the top view of the middle layer.

![2-top](https://i.imgur.com/URKworu.jpg)

This piece is labelled "OBD IO board". This piece has a QR sticker with a marking underneath.

Here's the bottom view of the middle layer.

![2-bottom](https://i.imgur.com/fXpsnzl.jpg)

A lot of small parts, but sadly nothing really identifiable unfortunately.

### Top layer

Here's the top view of the top layer.

![3-top](https://i.imgur.com/wN6tFhY.jpg)

This part is labelled "OBD main", but doesn't seem to offer much else in terms of information. There's a QR code, but the ID on it differs from the piece we saw in the middle layer only by one character (A vs B), meaning the sticker was probably only used during the assembly process. 

Here's a closeup of it.

![qr-code](https://i.imgur.com/W8FYCBO.png)


Here's the bottom view of the top layer.

![3-bottom](https://i.imgur.com/60n5Mr3.jpg)

One thing we see right away is that this part contains our flash chip -- a Macronix MX25L1606EZNI-12G.

According to Digikey, this is a 16 MB Flash SPI chip. https://www.digikey.com/en/products/detail/macronix/MX25L1606EZNI-12G/2744758

 There's a couple of other parts on this side of the board, but the etching on them has been rubbed off to the point where it's basically illegible.