Any RFM95 user reports?

mihai.aldea

Indeed, I see LoRa as an option for either experimenting, or as a solid alternative where there's no other option. Because at the end of the day, those who'll require a reliable transport layer will not resort to the open bands but use 2G/3G modems or even radio modems or satellite uplinks. While the LoRaWAN users will have to cope with the drastic FAP limitations, or use point-to-point systems for setups that allows no alternative, like I do.

alexsh1

@gohan true, but there are applications where Lora is more appropriate. High Altitude Ballooning is one of them

gohan

I am talking for more ground level needs :D

alexsh1

@gohan in a highly populated area Lora is better from my perspective. However, as already mentioned the cost is high (GW - €300, node - €55+ etc). Plus one is expected to develop

alexsh1

This is a moteino Lora node.
I understand the battery consumption is not an issue, but again I have not measured the current.

mihai.aldea

@alexsh1 said in Any RFM95 user reports?:

@gohan in a highly populated area Lora is better from my perspective. However, as already mentioned the cost is high (GW - €300, node - €55+ etc). Plus one is expected to develop

And why is that? Dense population = likely more users = frequent gw congestions.

alexsh1

@mihai.aldea

When I said Lora I'm referring to LoraWAN, which is not the same thing.

2G requires more power to transmit than LoraWAN
LoRaWAN is optimized for uplink (from the node to a server). For downlink there is 8 times less bandwidth available. This means it is designed to received info from sensors
A gateway can receive on 8 channels at the same time

All that said, the ideal use case for LoRaWAN is:

Simple sensors that need to transmit infrequently
Missing 5-85% of data at times is okay
Little ability to control this device
No ability to update device firmware over-the-air
Deployed in the dozens to hundreds

Some Automatic Meter Reading is a great example of a good use case for LoRaWAN. For meters that update the reading, say once per hour, it does not matter if some readings are missed, as long as some make it through.

Finally, places like Amsterdam were completely covered by LoraWAN in just two weeks. There is no chance for the city of this size to be covered by 2G in such a short time.

alexsh1

Couple of graphs:

alexsh1

And this has truely shocked me:

The ballon covered the distance 325km and was still some budget left in the receiver.

mfalkvidd

Regarding the cost, I have built prototype nodes on Wemos D1 Mini + RFM96 using these clones and wire antennas:
http://www.ebay.com/itm/231784606792
https://www.aliexpress.com/item/D1-mini-Mini-NodeMcu-4M-bytes-Lua-WIFI-Internet-of-Things-development-board-based-ESP8266-by/32662942091.html

alexsh1

@mfalkvidd when it comes to a loraWAN GW the cost is different - the DIY GW is going to set you off by €200+.

Rfm95/96 are cheap, but there are cheap for a reason. RN2483 is more expensive but it is loraWAN compliant.

mfalkvidd

@alexsh1 yes, absolutely. But is a private lorawan gw really relevant in a home automation scenario?

alexsh1

@mfalkvidd That's a loaded question. The same as NB-IOT, I think Lora may be used under certain circumstances in home automation though it is not designed for it.

For example, a friend of mine has got a summer house in a remote location. No internet and very weak 3G/2G signal. However, there is a loraWAN signal (it is in Holland). Of course, a good GSM antenna may help here. Or loraWAN can be used to send a message "all is OK with your house" once an hour. Is this home automation? Yes it is.

Like like yourself, I'm using Wemos D1 mini + rfm95 as a single channel GW and a few sensors just to tinker with this new technology and try to find the right application

mihai.aldea

Well, I'm glad that the posting got some traction and some very interesting ideas were shared. While the bits and pieces of information were all out there, your argument helped drawing some conclusions.

LoRa is NOT an option for HA. alexsh1 explained one scenario and I'm actually using LoRa (not LoRaWAN) in my building, but both cases make use of LoRa only because it's a new cool technology. @alexsh1 your friend could properly cover his home with 2G/3G signal either for free, by asking the provider to improve the coverage in that area, or by buying a GSM repeater. And I could ask a neighbor to share his WiFi connection so an ESP8266 module could do the job.
The protocol addresses very specific segments where a great urban coverage is required and for that to happen no node should exceed a radio power of over 100mW.
There is another case where everything was traded off for the sake of range, the ham radio JT65 protocol. I was able to successfully transmit a signal from Romania to Brazil using 5W RF power and a 1m diameter magnetic loop antenna. It's great for long distance, narrow bandwidth (200Hz wide channel), low power but it sends data at a "whooping" speed of 13 characters per 50 sec, during which it draws about 1.8A from a 12V battery (21.6Wh).
My original idea of LoRa <-> RFM69/RF24 is not feasible unless, some serious downsampling is involved, as buffering the raw data before sending it out is really useless because LoRa doesn't have a serious overhead that would be addressed by concatenating larger chunks of data in a single packets.

So at the end of the day, it really leaves us with a couple of applicable scenarios when taking public LoRaWAN meshes into consideration. Smart meters and perhaps security devices which only have to send a daily keepalive ping and if ever needed, tripped sensor alerts, provided that they would be immune to jammers. I'm not taking into consideration the close range stations where a daily 30s air time would suffice, because this defeats the purpose of LongRange. Other than that I see no real use of LoRaWAN, but feel free to share your ideas, perhaps I'm missing something.

And after apparently trashing both LoRa and LoRaWAN I will only say that I can barely wait to get myself a LoRaWAN gateway and set it up in my area :grin: :grin: :grin:

MikeR

Does anyone here have any code examples of the defines etc to get an RFM95 module (sx1278) to work in mysensors? cant find it in the API page. Many thanks to someone who can help

gohan

Look into myconfig.h, there are some in there

mfalkvidd

https://www.mysensors.org/apidocs-beta/group__RFM95SettingGrpPub.html might be useful

MikeR

@gohan Thank you, the one place i didnt look that i should have looked first

MikeR

@mfalkvidd Thank you, looks like that will help me as well.

Have had a bit of a tinker and still not getting the transport to initialise.

#define MY_DEBUG
#define MY_DEBUG_VERBOSE_RFM95

#define MY_RADIO_RFM95
#define RFM95_434MHZ
#define MY_RFM95_MODEM_CONFIGRUATION RFM95_BW125CR48SF4096
#define MY_GATEWAY_SERIAL


// Enable inclusion mode
#define MY_INCLUSION_MODE_FEATURE
#define MY_INCLUSION_MODE_DURATION 60
#define MY_DEFAULT_LED_BLINK_PERIOD 300


#include <MySensors.h>

void setup()
{
	}

void presentation()
{
	}

void loop()
{
	}```

Thats what i have for the gateway and this is the response

0;255;3;0;9;MCO:BGN:INIT GW,CP=RLNGA--,VER=2.1.1
0;255;3;0;9;TSM:INIT
0;255;3;0;9;TSF:WUR:MS=0
0;255;3;0;9;RFM95:INIT
0;255;3;0;9;!TSM:INIT:TSP FAIL
0;255;3;0;9;TSM:FAIL:CNT=1
0;255;3;0;9;TSM:FAIL:PDT```

Anyone able to assist? is the code right and its a hardware issue or is there more that needs to be in the code?

gohan

Double check for wrong wiring or a loose connection

Any RFM95 user reports?

99

11.7k

11.2k

113.0k