GPS on Field Tracker

Sorry if this has been covered already.

I'm helping with a semi professional early teenage football team, and I was looking at possibly buying a kit of GPS trackers for field position monitoring and recording. Unfortunately, the cost of these system is way way beyond my budget.

I was therefore wondering if it was possibly to design a system with the Picaxe kit. Trying to keep it relatively simply as my experience of programming is limited (especially for the front end system).

The ideal system would record players positions over 90 minutes, then be downloaded and displayed on a simple football pitch image. I would plan to make 11 kits, 1 for each player.

Any help / suggestions would be hugely appriciated.

Thanks
Rusty

It should be possible. Assuming longitude and latitude can each be stored as 16-bit, that's 4 bytes per entry so, sampling every second, that would allow 136 minutes of storage in a 32KB I2C EEPROM.

Thanks Hippy.

Are there ready assembled modules I can buy for the GPS side of things, cause I really wouldn't have the skill to design a full GPS circuit.

There's the ublox max-6 GPS breakout board which has a serial output so can be easily interfaced to X2 PICAXE -

http://www.picaxestore.com/index.php/en_gb/gps010.html

Hi,

There should be a reasonable choice of available GPS modules with an integrated "patch" antenna, that put out the standard "NMEA" serial data "sentences" at a fairly low baud rate. "Parsing" (decoding) these data strings is slightly complicated by the non-fixed-width numerical data fields, but you should be able to find PICaxe code on the forum, which can also supply "timestamp" data, so no RTC would be required.

However, don't overestimate the GPS positional accuracy, probably about 5 metres unless special techniques are used. Also, the "post-processing" and display won't be trivial; Latitude and Longitude angles don't correlate to the same horizontal distances (except at the equator) and the football pitch is unlikely to run exactly East-West or North-South, so a fair bit of trigonometry might be needed.

Cheers, Alan.

Be careful if you decide to buy a ublox NEO-M6 of a certain auction website - lots of fakes about.

I was caught out recently, it was sold as a ublox NEO-6, when I tried to re-configure to provide ublox binary messages, the commands were rejected.

Turns out it was a fake !!, based on a Hangzhou ZhongKe Microelectronics CO. AT6558 with a ublox lable on the metal shield.

Of course, I only found that out when I removed the shield, so couldn't really send it back.
It wasn't expensive anyway, so not really that bothered, just meant I had to buy another (bought a NEO-M8 this time).

Neil.

The more modern Ublox GPS, the 8 in particular do use a lot less power than the Ublox 6.

The modern Ubloxes GPSs will run from 2 x AAA Energizer Lithiums, these stay at 1.5V for a large part of their life, no regulator required in this setup. Normal AAA alkalines quickly go down to 1.2V each which is too low really, so you need 3 and then need a regulator so you dont overvoltage the GPS.

The 8M is far superior to the 6's & 7's I think.

Had 5 x 6's and 1 x 8 at one point, on the 8M, aquistion times were far quicker, HDOP, VDOP & PDOP was far better, also can track GLONASS EGNOS & GPS all at the same time.
Now I have 5 x 8's and 1 x 6.

Neil.

I use GPS modules with custom drones (not with PicAxe though), and even the $100-$200 modules, when connected to 12 satellites, may give you only as good as 3m accuracy. Every now and then I get less than 1m accuracy, but don't count on it. I can usually tolerate landing within 5-10 feet of where I took off so it works for me. If you are looking for precise positioning, down to the centimeter-level accuracy, read into using RTK GPS. It's expensive, but you pay for higher accuracy.