An application of multiple device communication?

[evan]

Hi,We plan to establish a star network where more than 20 devices could communicate with 1 host mutually and no-interaction between devices with nrf51822 we are using now. We have searched the information about the multiple link network and found out there are several approaches that could be likely to be available but not sure the feasibility for each approach including Gazell , ESB , ANT, nRF OpenMesh and FruityMesh . According to the description of each approach, they all are able to provide the ability to establish a star network . So could you please give any special advice that which is the most suitable one for our application? Thanks.

[Hung Bui]

Hi Evan,

For your application Mesh protocol maybe a little bit overcomplicated. You should use mesh only if you do plan to expand your network, so you have node that can forward messages.

ANT would support star network with more than 20 nodes, out of the box. ANT provides frequency agility and encryption also. However you need to pay a small license to use ANT. And it won't work on nRF51822 won't be able to run ANT. You need nRF51422 or nRF52.

Gazell and ESB doesn't support 20 nodes out of the box (max 8 pipes). But you can use a common host address ( one pipe) and use the same address for all of the nodes. You then use 1 byte in the payload to identify each node.

ESB is simple and easy to use and modify if needed.

Gazell is a closed library and is designed not for using with more than a few nodes at the same time. In your case you need to use all the node in unsync mode and sync mode won't work if you share same address with more than one node.

Both ESB and Gazell (link layer) doesn't support encryption. Gazell pairing support encryption but not with multiple devices.

With considering all these options, I would suggest you to try ESB. If you are fine to move to nRF51422, you can try ANT.

[evan]

Thanks Hung for your advice. It is quite useful for us to make the decision. I think ESB is easy and simple to use and also could customized for specific application ,but compared to ANT it needs more effort to test the communication quality and also possibly faces to the issue of frequency adjustment for better sync performance. So maybe we need move to nRF51422 and try ANT to get starting this application. In terms of license for ANT , under ANT license website we found the hardware license and software license, if using nRF51422 do we need pay the hardware license then how to pay the license? And if we don't use ANT+ ,just using protocol stack to setup an ANT network, then is this stack available by NRF softdevice SDK ?

[Hung Bui]

Hi Evan,

If you use the nRF51422 the fee is already in the price of the hardware, you don't have to pay. Software license is only applied for the nRF52. You can download and use the ANT stack from our website. Examples for nRF51 ANT are available in our SDK until SDK v10. From SDK v11 we only have example for nRF52 and ANT.