TomTom GPS unit as tractor speedometer?

[Gittyup]

WAAS increases accuracy considerably for any GPS so equipped, assuming you can see the satellites. It is not limited to aircraft navigation. Standard GPS is about 30 feet absolute accuracy, sometimes a lot better sometimes worse. WAAS is about 10 feet accurate. GPS performs better for speed accuracy.

A simple speedometer is way cheaper and simpler.

 

[lhfarm]

Barry - I put a bike speedometer on my TC21D. It has a magnetic pick up on one rear tire. You'll need to find one that the wheel diameter can be programmed to something close to what is on your tractor. $10 or so.

I actually purchased a bike speedo a few years ago, but couldn't figure out how/where to mount the pick up. Do you have pictures of how you did the mount and where you placed the head unit?

Thanks,

 

[putt_putt_green]

The accuracy was specked to be within 10 meters of accuracy. Real life accuracy turned out much better than this, especially with 2 dimensional positioning.

Hijack On

My first job out of college was working on the GPS ground control system back in 1989.

I had a $15000 GPS receiver in my $500 Chevette on my first day of work. They let me drive around with it. Unfortunately I ran out of gas, luckily only about 1/10 mile from a gas station.

My last project there was helping do a WAAS prototype, which was intended to sell to the FAA for landing airplanes. I spent 2 weeks decoding the signals from a RS232 equipped GPS receiver while our company lawyers and the receivers lawyers went back and forth about selling the documentation on the RS232 signals. I got a fifth of Bacardi Black Rum delivered to my office for this by the project manager. This was at IBM, who would fire someone for having an empty beer bottle in their car. The receivers were hooked to computers and sat on top of the rooftops of various IBM buildings. Once in a while, you would have to call someone and have them reboot the computers. Fine memories.

There was this genius mathematician there who had figured out how to get the accuracy down to less than a centimeter. It had to do with figuring out where on the wave you picked up the GPS satellite signal. I don't know what ever came of this.

Hijack off

 

[Treemonkey1000]

Putt putt that sounds like a fun job. I work in a Metrology lab and we do that sort of accuracy verification for our job testing Frequency counters..The accuracy of these GPS and ease of use is very cool. Beats using a Map and compass out in the woods. Although I still have them along if I am going out into the woods...

 

[lhfarm]

A friend loaned me his high-end Garmin nuvi 750 to try. This unit has a dashboard screen with a large speedometer in the center. He had also given me the car mount witch has suction cup and I stuck it in the middle of the instrument cluster. I made a couple of trips up and down the field. Worked perfectly. It was reading in tenths of MPH. I just set the cruise and the speed didn't vary more than a couple of tenths.

I may just ask if I can keep this unit for my spray job . I was/am a little worried about it bouncing off in the field, but the holder didn't come off the glass easily. I'd still like to know if the TomTom (at half the price) has a similar feature.

 

[Rara Avis]

A friend loaned me his high-end Garmin nuvi 750 to try. This unit has a dashboard screen with a large speedometer in the center. He had also given me the car mount witch has suction cup and I stuck it in the middle of the instrument cluster. I made a couple of trips up and down the field. Worked perfectly. It was reading in tenths of MPH. I just set the cruise and the speed didn't vary more than a couple of tenths.

I may just ask if I can keep this unit for my spray job . I was/am a little worried about it bouncing off in the field, but the holder didn't come off the glass easily. I'd still like to know if the TomTom (at half the price) has a similar feature.

Use a Foam Marker when spraying...its easier...
http://www.hypropumps.com/FileAttachments/Spray/en-us/404-SalesSheet-FoamMarker.pdf

 

[lhfarm]

Use a Foam Marker when spraying...its easier...
http://www.hypropumps.com/FileAttachments/Spray/en-us/404-SalesSheet-FoamMarker.pdf

I used the sprayer yesterday. I'm going to wait for the results to start showing before I post my success rate. But a foam marker would have been nice.

Here is a pic of the borrowed GPS unit with the optional industrial strength mount.

 

[pitt_md]

I need a speedometer for my TC40DA while running my sprayer. That doesn't happen often and I'm trying to find a unit I can use on the road (in the car) and off (in my field/woods). I have friends who have TomTom units ( a One and model 720) and really like they street features/operation. Anyone using either model in the field?

Other suggestions for an on/off road device?

Thanks,

Garmin and other brands make hand held units compatible for your operation but they might not have all the nice things that a street pilot or TomTom will come with. I have both a hand held unit that I use for hunting and fishing and a street pilot. I use the hand held for tractor work.

 

[denmansoft]

With the number of satelittes available today most new GPS units will give a decent speed in a open field situation.
Remeber that if your are going to take it into the bush (heavy tree canopy) all this goes out the window. Especially when it rains!
Most of my work with GPS over the last 20 years is to test the limits of where it doesn't perform well.

The next thing we are going to hear is wanting to hook up navigation and control systems to drive the tractor. No thanks. I like my seat time.