Very low power consumption wireless module + high range

Hello,

I am trying to build a Wireless Sensor Network for reading temperatures in a huge area. The modules will be based on batteries. I want to use a very low power consumption wireless module capable or transmitting + receiving data at 1000 meters maximum. The wireless module should also support broadcast. Can you suggest me a wireless module with the above specifications?

Thank you…

What do you mean by "broadcast"?

And (separate question) do you want the sensors to send their data to a single "master" or do they each need to send data to all the other sensors?

Does your figure of 1000m represent the radius of a circle with the master at the centre? If not, a diagram of the location of the sensors with approximate distance measurements would be useful.

Will there be obstructions (such as trees or buildings) between a sensor and the master?

How often will the data need to be sent and about how much data (how many bytes) will there be in a data message?

...R

Robin2: What do you mean by "broadcast"?

And (separate question) do you want the sensors to send their data to a single "master" or do they each need to send data to all the other sensors?

Does your figure of 1000m represent the radius of a circle with the master at the centre? If not, a diagram of the location of the sensors with approximate distance measurements would be useful.

Will there be obstructions (such as trees or buildings) between a sensor and the master?

How often will the data need to be sent and about how much data (how many bytes) will there be in a data message?

...R

I mean that all the nodes can send data to the center node (aggregator). No, not to each other. 1000 m is the maximum distance form the center node, like radius, yes. They will be set inside a forest, with trees between the center node and the sensor nodes. Data every 2 seconds.

Thank you...

Transmitting wireless data within a forest will be a challenge.

I suggest you investigate LoRa. I have no personal experience but I believe it is capable of very long range.

...R

Does the LoRa support mesh, and broadcast (anyone to anyone)? If someone knows...? Thank you

alex5678:
Data every 2 seconds.

Thats a lot of data.

Do the duty cycle restrictions in your part of the World allow you to do that ?

srnet: Thats a lot of data.

Do the duty cycle restrictions in your part of the World allow you to do that ?

I do not know. But I do no think there is a problem, I have never heard something about that...

Thank you

Well, I can see it as a problem, depneidng

alex5678: I do not know. But I do no think there is a problem, I have never heard something about that...

It would be an idea to check ...............

Ok, I checked it. No problem.

Does the LoRa support mesh, and broadcast (anyone to anyone)? If someone knows...?

Thank you...

Very low power and high range are possible with very good antennas. Are you working on that area, also?

Paul

I am electronics hobbyist...

What antennas should I use? Don't these antennas consume more current?

Thank you

alex5678: Does the LoRa support mesh, and broadcast (anyone to anyone)? If someone knows...?

If all the devices are within range of the master why would you need a mesh?

If every device sends data every 2 seconds what is the maximum number of devices that can be used without the transmissions overlapping and messages being corrupted? The answer depends on how long each transmission takes and whether they are all coordinated by the master.

...R

Robin2: If all the devices are within range of the master why would you need a mesh?

If every device sends data every 2 seconds what is the maximum number of devices that can be used without the transmissions overlapping and messages being corrupted? The answer depends on how long each transmission takes and whether they are all coordinated by the master.

...R

Ok, suppose I cover greater area and I use 4 masters. I want these 4 masters to communicate to each other.

Ok, that's definitely a problem, how do I fix this overlapping? I believe I should use mesh in this problem, so that each node broadcasts a flag, before sending to the master?

What type of batteries are you looking at using.? Battery powered radios which are always powered up are power hungry, especially the receivers. Transmitting every 2 seconds wont help either. Also frequencies above 400 Mhz get absorbed by trees, especially if the leaves are wet.

alex5678: Ok, suppose I cover greater area and I use 4 masters. I want these 4 masters to communicate to each other.

Worry about that later.

Ok, that's definitely a problem, how do I fix this overlapping? I believe I should use mesh in this problem, so that each node broadcasts a flag, before sending to the master?

Think about it. Sending a flag will increase (maybe double) the amount of wireless traffic. How is that going to help?

Before going any further you need to get some facts.

  • How long (how many bytes) will be in each data message
  • How long (in millisecs) will it take to transmit that message (which depends on the radio data rate)
  • How many sensors will be linked with a single master

and some general information

  • Why is it necessary to collect data every 2 seconds?

...R

Robin2: Worry about that later. Think about it. Sending a flag will increase (maybe double) the amount of wireless traffic. How is that going to help?

Before going any further you need to get some facts.

  • How long (how many bytes) will be in each data message
  • How long (in millisecs) will it take to transmit that message (which depends on the radio data rate)
  • How many sensors will be linked with a single master

and some general information

  • Why is it necessary to collect data every 2 seconds?

...R

I need real time sensing, that's why 2 secs. As I saw from the datasheet, it consumes 100mA Tx and 30mA Rx, which is near the solution of Xbees Zigbees I am using now, which consumes Tx:120mA and Rx:30mA. Is there any other module, apart from LoRa that can give me lower consumption?

Thanx...

900Mhz or 2.4Ghz (Zigbee, LoRa, Nrf24) might prove useless in a forest. 433Mhz (or lower) seems more suitable. The HC-12 (~433Mhz) does 1-2km in the open, but that might reduce to 100m in a dense forest. Leo..

alex5678:
I need real time sensing, that’s why 2 secs.

Real-time is not in itself an explanation for any particular interval

Why don’t you tell us what you are trying to create. Someone may have some good ideas that will help you.

…R

Wawa: 900Mhz or 2.4Ghz (Zigbee, LoRa, Nrf24) might prove useless in a forest. 433Mhz (or lower) seems more suitable. The HC-12 (~433Mhz) does 1-2km in the open, but that might reduce to 100m in a dense forest. Leo..

Ok, so I can use more nodes to be more close, due to the range of the HC-12. Does HC-12 support broadcast or mesh networks?

A HC-12 is just wireless serial, with options to change channel, transmit power, sleep, etc. Up to you to implement it all in software.

I would try a pair of each of the technologies in the environment where you are going to use them, before committing to a large mesh network. Leo..