💬 The Sensor Network
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A theroetcical capacity using RFM 95 LoRa radios in 433 MHz ISM band:
Lora Config bandwith: 125 KHz.
ISM band 433.050 - 434.790 MHz.
Allows for these 5 "channels";- 433.125
- 433.400
- 433.650
- not used (ISM noise from commercial devices on 433.920 etc)
- 434.150
6 .434.400
7 .not used (local ham repeater), (yes its nice to check!)
Each GW can handle 254 RF Nodes
254 x 5 RF channels = 1270 sensor nodes in any one geographical location. (including repeated nodes)?
p -
A theroetcical capacity using RFM 95 LoRa radios in 433 MHz ISM band:
Lora Config bandwith: 125 KHz.
ISM band 433.050 - 434.790 MHz.
Allows for these 5 "channels";- 433.125
- 433.400
- 433.650
- not used (ISM noise from commercial devices on 433.920 etc)
- 434.150
6 .434.400
7 .not used (local ham repeater), (yes its nice to check!)
Each GW can handle 254 RF Nodes
254 x 5 RF channels = 1270 sensor nodes in any one geographical location. (including repeated nodes)?
p@cloolalang you can also vary the spreading factor (6 alternatives) and the coding rate (4 alternatives), yielding 24x1270= 30,480 nodes. There are other options as well (encryption, directed antennas and more) but what to do will vary in each use case. Theoretical calculations can be fun, but they do not represent the real world.
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@cloolalang you can also vary the spreading factor (6 alternatives) and the coding rate (4 alternatives), yielding 24x1270= 30,480 nodes. There are other options as well (encryption, directed antennas and more) but what to do will vary in each use case. Theoretical calculations can be fun, but they do not represent the real world.
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@mfalkvidd Hello, you can give an example of how to do this ? and if it is possible to perform on a Gateways ?
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@frydrik all nodes, including the gateway, on the same MySensors network need to use the same settings.
Documentation for settings: https://www.mysensors.org/apidocs/group__RFM95SettingGrpPub.html#gaedc32edc29ffd4ecc2c849e39010069e
@mfalkvidd Thanks for the answer, I want to create a network for reading electric meters in a city with a population of over 500,000 people, the limit of 254 nodes is too small, yes, I understand that you can create more Gateways to share them after different frequencies, the spreading factor, coding rate, and I understand according to this scheme that the point where there will be Gateways will consist of several Gateways each will have as ex. a different frequency and only the nodes will be connected to it with its frequency, you can look at the sketch drawn by me. It gets too complicated, can it be done in a single GW or with a reduced number of GW?
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@mfalkvidd Thanks for the answer, I want to create a network for reading electric meters in a city with a population of over 500,000 people, the limit of 254 nodes is too small, yes, I understand that you can create more Gateways to share them after different frequencies, the spreading factor, coding rate, and I understand according to this scheme that the point where there will be Gateways will consist of several Gateways each will have as ex. a different frequency and only the nodes will be connected to it with its frequency, you can look at the sketch drawn by me. It gets too complicated, can it be done in a single GW or with a reduced number of GW?
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These technologies are quite expensive to make, mysensors comes with some pretty cheap solutions, I think mysensors can be used in urban areas where the density of electric meters is quite high, especially in the panels where the meters are usually installed are grouped several as ex. 4 and more, for this panel you can mount a node that will read the indications of all meters, thus drastically reducing the number of nodes and the cost will be even more attractive to carry out this project, I thought that these nodes can be made on esp8266 + RFM95 to gain greater distances between Gateways nodes, in rural areas I will think about implementing LoraWan, for me it is quite complicated to clarify with this technology.
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These technologies are quite expensive to make, mysensors comes with some pretty cheap solutions, I think mysensors can be used in urban areas where the density of electric meters is quite high, especially in the panels where the meters are usually installed are grouped several as ex. 4 and more, for this panel you can mount a node that will read the indications of all meters, thus drastically reducing the number of nodes and the cost will be even more attractive to carry out this project, I thought that these nodes can be made on esp8266 + RFM95 to gain greater distances between Gateways nodes, in rural areas I will think about implementing LoraWan, for me it is quite complicated to clarify with this technology.
@frydrik LoRaWAN nodes can be made with esp8266 and rfm95. I have done so myself.
LoRaWAN gateways are slightly more expensive, but they are able to handle at least tens of thousands of nodes which is 100x more than a MySensors gateway, so the cost per node is much much lower than for MySensors.
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the problem is that I can't find code examples for LoraWan nodes so I can start this project on LoraWan, first I created my own LoraWan gateways on TTGO LoRa32 SX1276 OLED, and on another module TTGO LoRa32 SX1276 OLED a test node as in the video on youtube https://www.youtube.com/watch?v=T40a51TAMDI&t=401s
something works but the number of messages that reach the gate are very small in 24 hours I can receive 5-6, the problem I think I miss a gateways with one channel, and the node transmits randomly on that 8 channels, in addition I do not understand how to combine a sketch that reads the pulses from a meter with the loraWan library, I can't find examples of how to do it, that's why I was enchanted by the mysensors community, it's simple to create a node to understand how it works,
in mysensors I found what I needed + it is a receptive community, if you have experience with LoraWan please guide me how to start creating these nodes, I found how to build a local LoRaWAN® Network Server, and unfortunately here I stopped -
the problem is that I can't find code examples for LoraWan nodes so I can start this project on LoraWan, first I created my own LoraWan gateways on TTGO LoRa32 SX1276 OLED, and on another module TTGO LoRa32 SX1276 OLED a test node as in the video on youtube https://www.youtube.com/watch?v=T40a51TAMDI&t=401s
something works but the number of messages that reach the gate are very small in 24 hours I can receive 5-6, the problem I think I miss a gateways with one channel, and the node transmits randomly on that 8 channels, in addition I do not understand how to combine a sketch that reads the pulses from a meter with the loraWan library, I can't find examples of how to do it, that's why I was enchanted by the mysensors community, it's simple to create a node to understand how it works,
in mysensors I found what I needed + it is a receptive community, if you have experience with LoraWan please guide me how to start creating these nodes, I found how to build a local LoRaWAN® Network Server, and unfortunately here I stopped -
@frydrik I have multiple years of experience with LoRaWAN, but transferring that experience from one person to another in a forum thread is not possible.
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@frydrik I have multiple years of experience with LoRaWAN, but transferring that experience from one person to another in a forum thread is not possible.
@mfalkvidd Hi, I have a question regarding the numbering of nodes, as I understood, 254 can be connected to a Gateway, if I configure a node of these 254 as a repeater then at this node they will connect in theory another 254, the question is how the handle can define this number of nodes?
#define MY_NODE_ID ------ does it work in the range from 1 -254? -
@mfalkvidd Hi, I have a question regarding the numbering of nodes, as I understood, 254 can be connected to a Gateway, if I configure a node of these 254 as a repeater then at this node they will connect in theory another 254, the question is how the handle can define this number of nodes?
#define MY_NODE_ID ------ does it work in the range from 1 -254? -
@frydrik yes MY_NODE_ID can be between 1 and 254. No, repeaters will not allow you to add more nodes to the same MySensors network.
@mfalkvidd thanks for the answer, but I have another question, why can't the number of nodes be increased to more than 254? Is it a hardware limitation or can these values be changed inside libraries?
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@mfalkvidd thanks for the answer, but I have another question, why can't the number of nodes be increased to more than 254? Is it a hardware limitation or can these values be changed inside libraries?
@frydrik Don't forget that each node can have up to 255 sensors and you can have multiple networks. So 3 gateways running 3 networks could have 193,548 sensors. Wouldn't that be enough? If not just add another gateway.
If you used every channel on an nrf24l01+ you could have 254x254x128 sensors = 8,258,048!
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@mfalkvidd thanks for the answer, but I have another question, why can't the number of nodes be increased to more than 254? Is it a hardware limitation or can these values be changed inside libraries?
@frydrik said in 💬 The Sensor Network:
@mfalkvidd thanks for the answer, but I have another question, why can't the number of nodes be increased to more than 254? Is it a hardware limitation or can these values be changed inside libraries?
Because the MySensors library is designed that way, and because sending larger addresses will mean that messages must be shorter that what's currently supported.
But MySensors is open source - anyone with enough skills, time and motivation can change it.
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@frydrik Don't forget that each node can have up to 255 sensors and you can have multiple networks. So 3 gateways running 3 networks could have 193,548 sensors. Wouldn't that be enough? If not just add another gateway.
If you used every channel on an nrf24l01+ you could have 254x254x128 sensors = 8,258,048!
@skywatch thanks for the answer, I understand that 254 nodes can be connected to a Gateway, and 255 sensors can be connected to each node, the question is how to apply this for reading electric meters where their number is considerably higher than 254, as with a node to read as ex. at least 20 meters?
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@skywatch thanks for the answer, I understand that 254 nodes can be connected to a Gateway, and 255 sensors can be connected to each node, the question is how to apply this for reading electric meters where their number is considerably higher than 254, as with a node to read as ex. at least 20 meters?
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@skywatch thanks for the answer, I understand that 254 nodes can be connected to a Gateway, and 255 sensors can be connected to each node, the question is how to apply this for reading electric meters where their number is considerably higher than 254, as with a node to read as ex. at least 20 meters?
@frydrik For a population of 500,000, say 200,000 customers, you are into commercial scale data gathering such as EON etc might deploy, a principal driver for the power companies fitting smart meters.
I would have to guess in a city of the size you mention, smart meters are already in place...
