MoTeC Global Forum

The Garmin unit that is spoken of in the excellent GPS Webinar is a 5Hz unit, before committing to buy is there a faster updating product available from any source that will be readable by the M800 for processing off car with I2? I do not have a Motec dash in this vehicle. Thanks.

I have the 10-Hz MoTeC unit which is upgradeable to 20-Hz, and it is WAAS enabled.
If you are doing anything where you "difference things" then higher speed is better.

And I believe that any GPS that outputs the standard NEMA info is understood over the RS232 or STC.
But you should try it.
I am using a STC because my RS232 is occupied.

I am thinking of upgrading my unit if you are interested in it.

Thanks for the reply, I may be interested in your GPS unit, how much would you be wanting for it, plus it would need sending to me here in the UK? Thanks. E-mail me direct if you prefer, I am at chris@chriswilson.tv Cheers.

Chris Wilson wrote:Thanks for the reply, I may be interested in your GPS unit, how much would you be wanting for it, plus it would need sending to me here in the UK? Thanks. E-mail me direct if you prefer, I am at chris@chriswilson.tv Cheers.

Email sent.
The big question is why GPS - which then goes towards answering what/which GPS.
The 20-Hz may not be as sensitive as the 5-Hz, but a lot of filtering might not help in a racecar.

Another question is why 20Hz ? and even 5Hz?
GPS alone is not precise and repetitive enough for "line" and "trajectory" analysis.

In i2, I use track mapping only to know where motor and driver "events" are located on the track.

The only advantage to use 5, 10 or 20Hz is when GPS speed is used in real time, for traction control as an example.

Angelo

Polux RSV wrote:Another question is why 20Hz ? and even 5Hz?
GPS alone is not precise and repetitive enough for "line" and "trajectory" analysis.

True

Polux RSV wrote:Another question is why 20Hz ? and even 5Hz?
GPS alone is not precise and repetitive enough for "line" and "trajectory" analysis.

In i2, I use track mapping only to know where motor and driver "events" are located on the track.

The only advantage to use 5, 10 or 20Hz is when GPS speed is used in real time, for traction control as an example.

Angelo

Precision, repeatability, and accuracy are not all the same.

It is all relative.
And it can be a relative measurement.
Accuracy and speed are independent to/of positional accuracy, and the same for acceleration.
A speedo works even when one is lost, and the rosary always hangs off of the rear view mirror at an angle when going around a turn - whether or not there is speedo.

If you can use the GPS for speed in the ECU in real-time, then how its it different in using the speed post-facto at 20-Hz?
And the acceleration can be derived from the position at a higher rate as well.