GPS based speedometer

[He Man]

Is there such a device designed soley for the purpose of monitoring your speed via GPS that i can use?

My speedo was never really accurate and since its half ass dead now, i need to get the sensor replaced, i figure id just leave it dead and go for a GPS based one so atleast if im passing a cop at indicated 80mph, i know im not passing him at 70. Cause im either shitting my pants and im going to speed up to get to the next exit if i see lights, or im just going to keep going cause im only 5mph over.

[hackers2r]

If you have an iPhone and want to figure out a mounting solution, there's a pretty slick app called v-cockpit that has a really nice info display with day and night modes.

[He Man]

i rather get a speeding ticket than an iphone.

[battlecry]

If you wait long enough, the insurance lobby and the DoT will force you to get one so they can use it to check on YOU.

[dennisd]

How about one of the bicycle speedometers.  They use a little stick on magnet and pick up and they are even programmable.  I've thought about adding one to my M1100 so I don't have to always compute how fast I'm actually going.

[somegirl]

How about one of the bicycle speedometers.  They use a little stick on magnet and pick up and they are even programmable.  I've thought about adding one to my M1100 so I don't have to always compute how fast I'm actually going.

The wired bicycle speedometers are pretty good (at least up to ~50 mph) but the wireless ones are notoriously subject to interference.  I once was going 85 mph while waiting at a stoplight near a train station, and apparently I go 0 mph with my little bicycle headlight on.

[Ohmic]

This is funny. I went through the same thing. I tried doing something about it.
A couple of months ago i placed a TomTom on the bike. All in all it turn out to be pretty much useless in sunlight as the LCD got drowned out by stray light. Especially if you had on polarized sunglasses or if your visor was also polarized.  I've long removed the device from the bike! A failed attempt that was.



I have yet to give up. I started work on a circuit based on the SiRF-Star GPS chipset. The circuit send pulses to your stock or third party speedometer such as the Motogadget or simple bicycle speedometer.  In effect your speedometer will read these pulses just like it would your normal stock reed sensor. It will also allow you to tune the output frequency based on the OD of your wheels along with a constant multiplier for the number of reed sensors(1-5). Some bikes have more then one sensor pickup. The output will be just that of the stock sensor, either 2wire reed type or 3wire open-collector type, but based on GPS signal and whatever wheel size configuration the user programs for the third party speedometer is tuned to accept. Simple!

Cool thing about this, is I can pull such information as heading to name a few. Maybe i'll make my own speedometer display with integrated heading information.

The prototype circuit went for a test ride with me in the truck hooked up to a frequency counter. The frequency did lock on to my truck's ground speed. The Analog portion of the circuit is proven. Don't know when i'll finish the alpha unit to install on the bike. Just need time to layout the board and design a package for it.

Pros:
- One less wire on the bike. No need for the stock wheel sensor. Cruiser ppl will love it!
- Great for muddy environment such as dirt bikes and quads that don't come with any speed sensors.
Cons:
- $$$

Not sure if i'll bring this to market. I'll have to see how the design function in real life application and what demands are for them. If you're interested in being a lab rat, let me know. I usually make 3-6 prototypes of anything i make.

[He Man]

i dont mind being a lab rat if i can get a discount on the final version if its not to expensive. :p

I live in NYC, and im notorious for getting my bike into shit, so i dont know if im your best candiate as a test rabbit since you might end up having to fix them several times over. 

But it will be nice to test it around buildings, RF and UHF interference, Bumps and potholes, rain, sometimes being knocked over, possibly restaurant grease...

[Ohmic]

NYC? Sure. You maybe very well be the perfect test subject. For tests and pre-production I charge for the raw material costs. It will be well below retail. ~$50-$75 to help me offset some of the R&D cost and tester to take ownership. The most expensive part is the GPS chipset. ~$35.

The only interference issue i see is if someone has a metal tank. In which case the module will need to be place either under the seat, or tank if plastic.
There maybe an option/need for either an external active or passive antenna for folks in a major city cores who are surrounded by skyscrapers or mounting issues in the bike.
All these design parameters will need to be tested. When i tested the prototype circuit it was done out in the open country with a passive antenna and the circuit placed on my truck's dashboard. Almost the perfect environment and same as where all the current car GPS modules are placed. Installing in a motorcycle will be another matter. Like i said, if it comes to it, I'll just design it an active antenna to boost the incoming GPS signals. Not a big deal. Just will cost more to manufacture. Nonetheless it will be a cool little project.

[TobyDanger]

I recently read about a similar project...

http://www.janspace.com/b2evolution/arduino.php/2010/06/26/scooterputer

[He Man]

let me know when you have one that is ready to be tested!

[WarrenJ]

My speedo is wildly inaccurate so I use my Garmin 60 CSX GPS clamped to the handlebar.  It has one page that shows distance traveled, current speed and moving time in large easy to see numbers.  Batteries last 2-3 weeks running an hour or so a day.  Not a cool solution, but pretty functional.

[Some Dude]

Have you looked at anything like This

[victor441]

The wired bicycle speedometers are pretty good (at least up to ~50 mph) but the wireless ones are notoriously subject to interference.  I once was going 85 mph while waiting at a stoplight near a train station, and apparently I go 0 mph with my little bicycle headlight on.

Sigma brand bike computers work fine well into triple digit speeds and are inexpensive....but as you said wired is the way to go, the wireless units don't work well on a MC

[4DoorSi]

i rather get a speeding ticket than an iphone.

A man after my own heart....

Just remember, what i don't, droid does.  There are several free droid apps with speedometers.  The display is a little hard to see in full daylight though.