track telemetry - data radio

[kb1gtt]

How much current does the device consume? This can be measured on with a multimeter.

I would generally keep the 232 GND and power GND as separate conductors.

232 on pretty much any wire is going to be fine. I would suggest twisted pair, but also for a 50ft run, it's not critical.

[stefanst]

I did something similar just running CAT5E. used one twisted pair for RS232 signaling, two pairs for power and power gnd and the last twisted pair carried signal GND and a warning light. I think I ran 57,600 baud and it ran well across my old house- coincidentally approx. 50'. Of course, since I'm always wearing a tinfoil hat and am just slightly paranoid, I did implement a checksum protocol to check for errors and allow re-transmit of bad packets.

[kb1gtt]

RJ45 breakout boards make this easier to use as well. Basically use a purchased cable and use short wires to make the custom connections. They cost about $2.50 on ebay.

http://www.ebay.com/itm/like/301671470706

[stefanst]

There's an article on Hackaday where somebody uses 433MHz telemetry equipment to beam internet at distances over 1km. The secret sauce seem to be in the protocol he's implementing. There may be some clues how to implement correction for errors here....
http://hackaday.com/2017/06/20/long-range-wireless-internet/

[AndreyB]

I have these baby 900 MHz magnetic base antennas with 10 ft cable and plain threaded connection between the whip and magnetic base. Under the round plastic sticket on the botton there is exposed metal which is connected to the outside of the connector and a magnet. http://www.ebay.com/itm/3-Pack-10-ft-900-MHz-5-dBi-Mag-Antenna-with-Magnetic-Base-SMA-Male-Connector-/351831450090 I guess I cannot shorten the cable really? Do we see any options with shorter cable?

Also have http://www.ebay.com/itm/SMA-Female-To-RP-SMA-Male-connect-SMA-to-RP-SMA-RF-Connector-Adapter-USA-/111516107525 so male cable and male radio are connected to each other.

I also have weldable (clean?) 22GA and plated 26GA sheet metal for raised GND plane. Open question how big plate and how to mount this plate on the round vertical 1.25" mast. Do not want to make it too big since it would decapitatete someone once I stumble over it. Round or square? Square would be easier to make

On the car I guess the roof would be the GND plane?

[kb1gtt]

What's the gab between the holes on the modem? I suspect you can simply attach that to the pole with some U bolts similar to these.
https://www.mcmaster.com/#3201t19/=18exy8t

I suggest the modem at the top of the pole, with 232 cable running down to the laptop. Use an atenna similar to the below. Keep in mind the signficant losses of RF in the 10 ft run of coax, even though this atenna has less gain, it gets out more watts of RF because it doesn't loose the energy in the coax. However more imporant, it would hear the car better as that also does not get attunated by the coax.
http://www.ebay.com/itm/900MHz-2100MHz-5dBi-Omni-Antenna-Tilt-swivel-SMA-male-plug-for-wireless-router-/151097037133?hash=item232e15d14d:g:APIAAOSwGzlTxQFJ

If you put the mag mount on a plate, you can mount it with a pipe flange adapter like this.
https://www.mcmaster.com/#4881k215/=18exz8a

[AndreyB]

Accesorry catalog http://www.mouser.com/catalog/645/cad/16.pdf probably tells me that I've got 1/2 Wave Wireless Transceiver Antenna 2 dBi Indoor Antenna http://www.mouser.com/search/ProductDetail.aspx?R=0virtualkey0virtualkey0600-00024

[kb1gtt]

On a prior page of this thread, I show that a 10ft length of cable which is higher quality than what you have has an attenuation of about 3.5db. So even if you get a 5db antenna on a 10ft length of cable, your overall db gain is 1.5db. As well keep in mind to get the increased db, that antenna is simply focusing the RF energy into a kind of torus, such that more energy goes out the side, instead of up and down. If this torus is to flat, you may not get energy down at ground level where the car is located. The OEM antenna is pretty close to Omnidirectional. You would be better off with your native 2db gain antenna with the modem on top of a pole. I would think 10ft in the air is good enough, 20ft might be better, but might also be just as good as 10ft. If you have metal garages at 10ft tall which get in the way, than getting taller than those garages is probably a good thing.

I guess the first thing is to get it working better on the pole, and to see if it will stand up, or fall over, sway in the wind, etc. This can be easily done with duct tape, and putting the pole in your back yard.

If it starts working well in this configuration, I would suggest putting it into an enclosure for weather / sun protection. Something like the below might work. You would have to poke the antenna through a hole, and you would have to some how seal that hole, such that rain doesn't get into the top of the enclosure and down into the electronics.
https://www.automationdirect.com/adc/Shopping/Catalog/Enclosures_-z-_Subpanels_-z-_Thermal_Management_-z-_Lighting/Enclosures/Polycarbonate_Enclosures/P6063

See below strain relief which can be used on a 5mm to 10mm diameter. Is the antenna over 5mm and below 10mm?
https://www.automationdirect.com/adc/Shopping/Catalog/Wiring_Solutions/Cable_Glands_-_Plastic/PG_Thread/BMX-13-W

Also you could use this strain relief to mount the box to the pole. Basically put the pole inside the box, through one hole, then this clamps down on the pole such that it doesn't fall off and weather doesn't get in etc.
https://www.automationdirect.com/adc/Shopping/Catalog/Wiring_Solutions/Cable_Glands_-_Plastic/PG_Thread/BMX-18-W

You could get this all into one nice connector if you used an RJ45 bulkhead connector like this
http://www.ebay.com/itm/Cat6-RJ45-Shielded-Industrial-Panelmount-Jack/301949752047?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D41376%26meid%3Dd5e5733a8a3d4ecd8cd256aaebe4d9e1%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D172347051705

[AndreyB]

20ft pole (forgot to take a picture while assembled) on a tripod with default antenna in my backyard. Little problem is that the building is taller than 20ft

Very little improvement. At some location further away than before car would transmit test text to raised base station, but similar test traffic would not go from raised radio to car radio. Tried default antenna and the eBay antenna with 7 db / 10ft cable / magnet to the roof.

Will place order for the white antenna. Need to think where can I test all this without too many buildings around. Oh, there is a nice cemetery close by!

[AndreyB]

Getting ready for a field trip this weekend. Any predictions which (if any) combination would cover one mile?

Left to right:

white 900MHz/2100MHz 5dBi Omni 3G Antenna Tilt and swivel SMA for wireless router

rubber ducky with yellow tag 900MHz 915MHz 5dBi Omni GSM Antenna Tilt-swivel RP-SMA for UAV FPV Drone Router

OEM 1/2 Wave Wireless Transceiver Antenna 2 dBi Indoor Antenna

900 MHz 5 dBi Mag Antenna with Magnetic Base SMA Male Connector now with replacement 5ft cable

[kb1gtt]

I think OEM will be best. What is the setup? Is the pole going to be mounted with router and OEM antenna on top, and RS232 cable running down the pole? Is the car going to have the router mounted to the roof in a weather tight box?

[stefanst]

How about LORAWAN? New record (a little cheaty) set at 702km.

https://hackaday.com/2017/09/11/the-things-network-sets-702-km-distance-record-for-lorawan/

[NoellEagan]

Hi...i am a new user here. As per my knowledge there are some purpose-built telemetry system as well, but as far as I understand they don't send that much data.Yet another option is getting a set of video transmitter and receiver, and an OSD chip on the transmitting part, so that you can overlay muliple values ontop the video. On the reveiving part you might need some decoding software.

pcb assembly

[Abricos]

for a long distance over 20 kilometers wi-fi antenna...
as I understand the range of the signal depends on the amplifier ... with the same antenna ...
information in Russian but you can see the photo and
have an idea

[video]https://youtu.be/3zHXu2EXVEc[/video]
http://www.lan23.ru/wifi/fa20PCB/fa20-wi-fi.htm