Hi-Kick Racing: Racechrono - Reasonably priced datalogger (GPS Lap Timer and Data Logger )

I have been timing my laps and analyzing my driving and car tuning through a GPS data logger. There are so many options out there, ranging from an enthusiast level logger such as the Performance box, to full-fledged expandable professional solutions like the Race-Technology DL-1. Prices range from 400 dollars to many thousands of dollars. Some of these products are very solid and capable. Others are kind of crap. For example, MaxQdata sells a product called "TraQr." It is priced at nearly 300 dollars. As far as I know, the unit is nothing more than an off the shelf GPS logger that is available for much less. In fact, if I recall correctly, the MaxQ unit even looks similar to an off the shelf unit with a different logo on it. And there are those units out there where you can pay a hundred dollars or more than this solution I am about to propose, for simplicity (usually these are standalone units) and a bit of added capability.

My advice is this. Do some research before you plop down cash on any data logger. A lot of research. I wouldn't have found out about this solution if I hadn't done so.

I have been running a 5hz data logger for about a year now. Recently, I switched over to a 10hz logger. Some of the things I can do with this rig are as follows: lap timing, lateral and longitutional acceleration (G-forces), lap comparison with a lap from any session, traveled route. If I spent a bit more money and had an OBD-II car, I can do even more.

So what is the cost of all this? As low as 80 dollars to a maximum of 120 dollars. Yes and it is reliable. Yes it is light weight. Yes, it can be a live timer. Yes, there is a lot of community support. All possible thanks to these guys:

(Image is a link)

Racechrono is a very capable, free, data analysis and lap timer software. It is being constantly updated and best of all, it is free! It supports Windows Mobile and Symbian operating systems on phones. Of course, there is also version for your personal computer. I won't go too much into details, but I have some screen shots on the bottom. You can also read about it on the RaceChrono website.

Items needed
So what do you need for live timing and data logging? There are several different ways to do this, but this is probably the most cost effective way.

1. A Smartphone or a PDA

Samsung Blackjack. Old, but gets the job done.

You need a smartphone that either runs on Windows Mobile 5.0+ or Nokia S60 2d ed.+ with bluetooth support. This part can be really cheap. My first phone for this rig was an old Samsung Blackjack. It cost me 50 dollars for a good condition used phone with several chargers, car chargers, extra battery, and audio output adaptor. Slim, light, got the job done. But If you are going to run the 10hz GPS receiver, I recommend a phone that runs on Symbian. This is because the 10hz receiver seems to have some issues logging at 10hz unless you set the baudrate manually through the Racechrono software, and this trick doesn't work on Windows Mobile phones. I currently run a Nokia 5340. It feels like it works much better with RaceChrono. Having a large, touch screen makes it a lot easier to use in the cockpit. I also recommend a phone with SD card support. I hate using cables to upload data. I used this website to look up phone specifications: Phonescoop

2. GPS Receiver
There are many options out there. I recommend the QSTARZ BT-Q818X for 5hz, and QSTARZ BT-Q818XT for 10hz. This is because these units are cheap and hassle free. Other units need to be set to 5hz through special software on your computer. These units have an external switch that selects the rate (Off-1hz-10hz). The price differences between the X and XT model is very small; just go ahead and get the 10hz model. If not, you have an option of getting other bluetooth receiver-only models (like the ones I mentioned) or getting one that internally logs. There is no point on getting the latter unless you want to manually export the NMEA data and upload it to your device later.

Qstarz BT-Q818XT

Note: when you shop for the receivers, do some research to find out if the update rates are actually what they claim to be. Often times they are 3-4hz units that interpolates internally to 5hz, or it updates at a certain rate but its ability to log it doesn't match the update rate. There may be other issues as well. The units I recommended work just fine.

3. Securing the receiver
I used to use blue painter's tape. I got tired of that so I went out and bought heavy duty velcro from wal-mart. The adhesive is can be very strong, and so is the velcro. One patch at about 22mm diameter is plenty enough to hold it in place. I used two. Minor problem is that the rubber backing on the BT-Q818XT doesn't work with the adhesive. I simply peeled the backing off using my finger nail. Its tough but it will come off.

Setup
1. Download the Racechrono file from the website
2. Download it to your phone. I used my SD card to do this.
3. Run the file using your phone's file explorer application.
4. In the RaceChrono menu, go to Settings -> GPS Receiver -> Baudrate and set the baudrate to 115200.

How to record a track
1. Start a new session. Write your session title, Driver, and then go into the Track option.
2. Select on "Create new" and write a track name.
3. Select "start" on the bottom left.
4. Drive a full lap. Don't forget to do a outlap, warm up, and a cool-down lap!

How to set start/finish line
There are two ways to do this. In-car, and after your laps. Don't do the in-car method. It is stupid and you will get off your line as you lose concentration. After you do your laps, park your car at the pits. Make sure your session is paused: if not, click on "pause" at the bottom. Browse traps -> add new -> start/finish line. Either use the directional buttons or if you have a touch screen, drag the screen left and right. You can zoom in for more accuracy. Hit "OK" at the place you want. If you are doing an autocross walk, you can set start and finish seperately as well.

How to set splits
Follow the same procedure above, except if you already have a track plotted out, you don't have to have the timer running (resume session). Add splits as desired.

Live timing
Very simple, as you start the session just hit "start" or "resume" and then hit "switch to live timer." If your phone has an accelerometer, it will recognize the position of the phone by itself and orient the display landscape or portrait. If not, you can go into the menu and set it up manually.

Overall impression
I really like it. My old 5hz unit would (probably through interpolation) match the Performance box times when I ran them together. The 10hz unit must be even more accurate. The 10hz logger is apparently an actual native 10hz that really logs at that rate. Amazing for the price! The Racechrono software is very capable and very complete; it is just as good as high-end systems are. Furthermore, you can expand it with a bluetooth OBD2 reader and log even more parameters. You can find out how to at the Racechrono website. Racechrono for your PC can import and export data to many different formats, including format that is compatible with Racelogic and other data analysis software. This adds so much versatility to this system. And it is so affordable. If you are a professional team that needs to log shock position at 100hz, have steering and brake position sensors, and need 20hz+ GPS log rate, this unit is obviously not for you. But if you are an enthusiast, club racer, or autocrosser, this system will carry you a long way.

Teaser

Also free, made using 5hz data.

BT-Q818XT can be found at amazon for a good price. Phones can be found on ebay, newegg, etc.

Various photos, screen shots. Last photo courtesey of RaceChrono. Click for bigger picture.