Davis CarChip EX

I saw this thing on TechTV and couldn't resist.

First, the Davis website:

http://www.davisnet.com/drive/products/carchip.asp

Essentially, on practically all cars produced after 1996 there is something called the OBD2 socket hiding just under your dashboard. Here's the install on my Lexus RX300

There are some exceptions and they are listed at the website above.

OBD2 stands for 2nd generation On Board Diagnostics.

Davis sells the CarChip. This device plugs into the socket and records all kinds of interesting information. The CarChip comes with software that allows you to download the data recorded into the chip during driving sessions. That software also provides views of that data in various ways (summaries, tables and plots).

I've exported the data and dumped it into Excel.

Here are a few graphs of my first ride with the CarChip. I drove approximately 24 miles into town. During that drive:

Here's a graph of the speeds recorded every 5 seconds by the CarChip. When I look at this graph I can easily see different roads I drive on during the trip to town. Of course, during a long trip it might be a bit confusing without a reference to where you were at a particular time but ... it's still interesting information.

Here's my engine working. The blue line is a recording every 5 seconds of the number of RPMs my engine was generating. The red line is the percentage the throttle was depressed.

Blue line, the coolant temp, red the battery voltage, once again recorded every 5 seconds.

I purchased the EX version of the chip. Look at their website for details on just what the standard and EX versions of the chip will record. You may only want the standard data.

I can't wait to see how this works out when I go on a long trip. Should be interesting.

A Few Gripes

You'll need a serial port to interface the chip to your computer. Time to move on to USB I think? Also, and this is the pits, you need to supply the chip with 9 volts of juice to power it while connected to the computer. It's ungainly. However, Davis provides all you need. They include a custom serial cable that includes an input for power from the AC/DC power adaptor they also provide.

Some Praise

I got the software installed and had the chip connected and running without reading the manual. After actually reading the manual, I managed to configure the chip for the parameters I wanted to record and set the time into the chip in a matter of minutes. So, you won't be spending too much time scratching your head wondering what to do. It's all pretty straight forward.