Hello,
i have built an rc boat that takes advantage of lora technology for the communication with the base. I am using the bsfrance lora 32u4 II module. It has an SX1276 lora modulator and transmits at +13 dbm with lora mode by default with the use of arduino RF95 library. So the descreption of the module and other users stated that it can reach a range of 1 km (maybe more). I have tested my boat on a lake with nothing between me and the boat to affect the connection and the rssi was -85 just at 100 meters away just by exchaning char bytes with the onboard system! Thats way shorter than 1 km. Should i change smth on the board? i dont understand.
Hard to say without pictures and schematics of your exact setup.
A few things come to mind:
- location of antenna
- material your boat is made of
- interference, perhaps your boat motor
Have you tested the module before installation in your boat? What range are you getting then?
That is plenty of signal, and your one-off experiment is not a valid range test. Expect an connection as low as -110 dBm or so.
If you want to know the actual range to expect, do a serious test.
the radio guy mantra: solve RF problems with antennas.
the rubber duck is half of an antenna. the other half is the ground plane. if you don't have a ground plane the ground leads on your board are your ground plane
short and simple: you need a sheet metal disc or a cone, 1/4 wavelength diameter, 90 degree angle to the antenna, connected to ground ( board ground, not earth ground ). this acts like the other half of your antenna
if you are running 915 mHz - 33 cm band, you need a 33 cm / 4 = 83 mm =3.25" ground plane on both antennas for optimum results. bigger is fine, it does not have to be round
for vast amounts of detail use these search terms: vertical dipole, Marconi dipole, ground plane, at any amateur radio antenna site
a high gain antenna on either end benefits both ends. standard rubber duck dipoles have 2.14 dbi gain ( there is no short and simple explanation of dbI ). the maximum legal LoRa antenna in the USA is 8dbi. an 8 dbi base station antenna should give you 6 db more on both ends of the link. this should give you 4 times the range
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My understanding is that the data rate has an effect on the usable range. Is there some way to use a lower data rate?
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