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Topic: HC12 Range Issue (Read 180 times) previous topic - next topic

chandu_csg

Hi all,

      I'm using HC12 modules to create wireless transmission of sensor data. According to datasheet it provided 1.8KM in open space(FU4 mode). I tried all possible combination the max distance i get is about 210meters(without data loss) and 260meters(with data loss).Still not tested in complete open ground.

              The other thing i observed is I'm getting almost same distance in FU3(4800baud rate) and in FU4 mode(1200baud rate). Changing antenna from spring to SMA also dosn't making any difference.

Few things i need to know,
1)What Max HC12 transceiver range can be obtained in FU4 mode and FU3 Mode without any data loss!?
2)Do i making any mistake in doing testing like type of antenna, delay between data transmission(i'm giving 1s) or the place of testing(i tested in Residential Area) !?

srnet

#1
Jan 22, 2019, 12:16 pm Last Edit: Jan 22, 2019, 12:18 pm by srnet
The distance between good line of sight (hilltop to hilltop for instance) and what you get on the ground (in a residential\urban area can be very significant. So the distance your getting might be normal.

The spring antennas are fairly inefficient, so a proper antenna should make quite a differance, a 17cm bit of wire for 434Mhz ought to be significantly better.

SMA is a socket type, its meaningless to use it to describe what type of antenna you have, an antenna with an SMA plug\socket on it could be any old bit of junk.

This might provide some pointers;

Reception Distances at UHF my 1000:1 rule

  
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chandu_csg

Thank you for your Suggestion,it cleared most of my doubts.I will do range test using 17cm wire antenna and am really curious to see the Results.

Thanks and Regards,
Chandan.

srnet

I have tested FSK style tranceivers similar to the HC12 extensivly in the urban area by me, where there are houses in the way between TX and RX.

The range I get at ground level with handhelds, for data packets @ 1000bps @ 100mW would be around 300m maximum.

The same setup was good for 40km between hilltops.

Such are the very large distance differences between urban areas and good line of sight.
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

chandu_csg

Thank you once again for your suggestion, i tried with 17cm antenna and i got 50meters more than previous result. Need to check on Hill top.

I have few questions,
1)40Km which you got is using Arduino or any Development KIT!?
2)Is there any module other than HC12 where i can get long range communication using Arduino!?

Thanks And regards,
Chandan

srnet

Quote
1)40Km which you got is using Arduino or any Development KIT!?
The processor used was in that case a PICAXE. The processor used has no affect at all on the sensitivity and distances of the RF device of course.

Quote
2)Is there any module other than HC12 where i can get long range communication using Arduino!?
Indeed there is. I repeated the 40km hilltop test with LoRa devices a couple of years later, they covered the same distance with a mere 3mW versus the 100mW needed by the FSK device.

The current one way record for a LoRa device is 702km;

Record 702km

If anyone can spare me £25,000 it would fund a small satellite launch, and I estimate you could receive LoRa packets on a Arduino UNO based handheld receiver at 2000km+.
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

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