LapRF Personal Race Timing System

Just like the title says, the LapRF is a personal race timing system recently released from Immerison RC. We had the pleasure to test-drive this product for a while and provide feedback on it’s operation and software development portion as well.

LapRF with External Antenna

Expect little and be surprised

Since this is a “Personal Race Timing System” it was designed to measure the precise┬átiming of the laps of a single racing quad. In that this device excels and it provides much more. When we received this “puck” as everybody call it, the software was still in development stage, however on the first try we managed to hook it up and connect it to our iPhone or iPad, pick up the Bluetooth connection and read/save settings to it. In a matter of seconds it was operational.

How it works:

The LapRF has a single 5.8Ghz receiver inside armed with a clever firmware to measure the RSSI (receiver signal strength indicator) value when a transmitter is near by. You can see a visual presentation of this if you switch to the “Diagnostics” page and if you bring your racing quad closer to the LapRF the line measuring your signal strength should increase and as you move it further away should decrease in length. If you plan to measure more than one racers with the LapRF, then the single receiver will be listening half time to one pilot, the other half to the other pilots frequency. Since it has to switch between frequencies to listen to both, this decreases the reception speed, and accuracy. The more pilots you add, the less your gate speed should be to get accurate readings.

Testing and racing:

The first test of tossing a racing quad or a small transmitter above it registered the time right away as it was enable for racing or practice. Then a more thorough test followed where we put the LapRF puck inside of a racing gate and started measuring laps as we passed through the gate. This was all indoors, and the distance from the puck to the phone was only a few feet. To our surprise, 2 and later even 3 quads were timed perfectly, of course within the limitations of the speeds advertised on the setup page. The Babyhawks we were flying had to make a 180 degree turn before passing through the gate on the below video which slowed down the gate speed considerably:

Armed with the successful results from the above test, we took the LapRF puck outside for some further testing. In order to increase the range of the Bluetooth and stay at a safe range from the racing gate and track, it is better to have sufficient range to keep the phone/tablet around the flying stations, while the timing gate is 30-50ft away from you.

Upgrading the Bluetooth antenna:

To upgrade the Bluetooth range we used items similar the following kit:

LapRF Bluetooth upgrade kitand here is the video of the procedure:

After he antenna was upgraded we headed outside to test the range on the newly upgraded LapRF Bluetooth antenna.

Range testing:

I personally do not really trust the Bluetooth standard. I have tried many Bluetooth headsets for different phones and my general opinion is that if it has to pass through your body, the signal degrades with 50% and the other party can’t hear you good any more. However I was pleasantly surprised on the range results of the upgraded LapRF. I have to specify here that in my tests I used a 7dbi 2.4Ghz antenna specifically designed for WiFi routers. Using a lower gain antenna will somewhat diminish your results, but even with a 2.15dbi antenna like in the upgrade kit above should be able to give you a good 50-100ft range. So here, watch the video I posted about my range tests:

As you can see, I had perfect Bluetooth communication from 147ft away, about 55 meters, which I think it is pretty awesome, compared to my very expensive Bluetooth headset which often does not pass through my body.

With all this I am very pleased with the LapRF, and while I am not a racer, now every time I can I get my buddies to come over with their Babyhawks so we can race together and have lots of fun.

You can purchase the LapRF and upgrade kit from out website, by clicking on the following link: http://www.nghobbies.com/cart/index.php?main_page=index&cPath=207_340