Hi
I’m just starting out with a LoRa node and am finding it difficult to connect to a Gateway. I should be about 500m from one, but only when I am withing 30m of it can I get a connection (join).
Will changing the antenna make any difference?
Currently I amusing a Molex ISM868/915 (1052620001)
Any help appreciated.
Regards,
Lou
My experience is that this antenna works OK when glued to ABS material.
A “real” GP-antenna is better than this one.
[quote=“LouThings, post:1, topic:36640”]
I’m just starting out with a LoRa node and am finding it difficult to connect to a Gateway. I should be about 500m from one, but only when I am withing 30m of it can I get a connection [/quote]
PCB antennas like that will not be as effective as a more conventional wire antenna.
However if the range is as low as 30m, either the antenna you are using is faulty, or there is another problem.
Incidently, if your quoting a bit of hardware, its good idea to provide a link to devices datasheet, you probably know it, and if you provide it everyone is saved the time of searching for it.
What sorts of RSSI are you getting for the uplink packets (either data or join request) at various ranges?
It’s tempting to wonder if your antenna isn’t actually connected
Unless you have evidence from other nodes to compare against, the problem could be at either the node or gateway end.
There are also three distinct output pins on common LoRa chips, so if software operates the chip in a way inconsistent with the board the chip is on, you could end up with the antenna effectively not connected. It’s also possible to try to operate a board built for 868 MHz on 915 MHz or the reverse, in which case the chip will work (as it is the same) but the surrounding RF networks will be wrong for the frequency of operation.
You should be able to get several kilometers line of sight with just a correct length wire antenna, ie 1/4 wave monopole against a ground or a 1/2 wave dipole.
Thanks for the tip; in future I’ll include a link to the HW.
Hi
I’m getting the following RSSI from my home location (approx 500m):
RX[freq=869.5,sf=12,bw=125,rssi=-113,snr=-20.00,len=37]
After moving to about 30m I get the following:
RX[freq=868.1,sf=8,bw=125,rssi=-113,snr=-7.75,len=33]
If that is at 30m from the gateway, either the gateway has a serious problem, or you node does not have a working antenna.
As well as providing a link to the antenna in use, its possible that revealing which LoRa node you are using would be helpful to the forum also.
Hi
Sorry for omitting the links to the parts in question (an obvious newby error ;-))
The link for the antenna I am using is: https://www.molex.com/molex/products/part-detail/antennas/1052620001
And the node I am running is a Miromico FMLR-61-U-RSS3-4M based on a SX1261 with a Renesas S3A6 mcu: https://miromico.ch/portfolio/fmlr-module-renesas/?lang=en
Whats the power consumption of the node when transmitting at 14dBm ?
The SX1261 can use a DCDC converter on the TX side (the SX1262 cannot) and this ough to cut power consumption in half, very useful for battery powered nodes. The SX1261 on that module does appear to have the required inductor …
Hi the current consumption when transmitting at 14dBm is 25,5mA @ 3V
RX mode is 4,6mA
Sleep mode is 1,4uA
Wow, the SX1261 is the future.
Equivalent figures for other devices @ 14dBm are;
SX1276 transmitting at 14dBm is 45mA @3.3V, RX mode is 16mA.
SX1262 transmitting at 14dBm is 55mA @3.3V, RX mode is 11mA.
SX1268 transmitting at 14dBm is 48mA @3.3V, RX mode is 10mA.
Thats with a ATmega328P that has an idle current of circa 4mA, sleep mode 2.5uA.