Set radio range of node in ble mesh.

[Pooja]

I want to test the mesh network for that i have to set the radio range of node to minimum distance so that i'll able to test the relay node example. Will you please help me to set the minimum radio range for node programmatically or is it possible to set the radio range? 

[John]

I do not believe you can specify a range for the radio. However, you can control the transmit power of the radio and therefore have some control over the range of the radio transmissions. Take a look at sd_ble_gap_tx_power_set in the file ble_gap.h.

[Pooja]

Thanks for your response. I have used the same method sd_ble_gap_tx_power_set but i didn't get any required result.

[John]

Not sure what didn't work for you here. Did the function call return a error code, or was the range still too large for your test?

[Pooja]

It doesn't return any error code the range is still too large.

[John]

When we've run into these kind of problems in test one option was to further attenuate the signals by using copper mesh faraday material over the devices, or you can buy RF resistive foam relatively cheaply and make a cheap RF isolation chamber by gluing pieces together into a cube.

[tesc]

Hi,

Another option may be to simply cut the antenna cable or antenna itself. For development that should not be a problem, as long as you are happy with permanently decreasing the RF performance of the board. Also, if you use the DK you may try connecting to J1 either a bad antenna or just a cable.

For production testing you would have to decrease tx power, use a Faraday shield, or otherwise put the devices near out-of-reach. It is not possible to decrease tx power beyond the lowest setting provided through the APIs.

Regards,
Terje

[Pooja]

Thanks for your response

[Pooja]

At what distance radio range of single node reach in mesh network.

[tesc]

Hi,

You can send messages from any node in the network to any node in the network, as long as the number of hops to get between the nodes is less than the TTL. Maximum TTL is 127.

The range for direct communication between two nodes depends on many factors. It is similar to that of a beacon. I would say in most situations you will get a few tens of meters of range indoors, but again it depends. See this thread for more information: nRF52 and nRF51 (Beacon) Range.

Regards,
Terje

[Pooja]

Thanks tesc.