Point to multipoint Gazelle sensor project, help needed.

RE: Point to multipoint Gazelle sensor project, help needed.

Avi_H — Tue, 28 Mar 2017 19:53:11 GMT

Hello Hung and thank you for the reply. You are right about the time budget, I will reduce sensors or time. I will look into ESB

RE: Point to multipoint Gazelle sensor project, help needed.

Hung Bui — Fri, 24 Mar 2017 11:59:51 GMT

If your plan is to have more than 8 sensors then you have to go back to what you already doing, use one byte as extra address for the sensors.

It's important that you have to implement something to avoid collision. If 2 or more sensors transmitting at the same time it will cause interference (the same applies if you have less than 8 sensors and have different pipe for them).

Gazell was not made for multiple device (more than 2) connect simultaneously. I think you should consider to try ESB.

How could you expect to have up to 50 sensors which has 50ms interval ? If each occupies 1ms for communication, we already don't have enough time domain for all of them.

To avoid collision you would need much slower interval.

RE: Point to multipoint Gazelle sensor project, help needed.

Avi_H — Thu, 23 Mar 2017 21:27:56 GMT

Hello and thank you for the swift reply. I would like to use up to 50 sensors, what can be done in this case?

RE: Point to multipoint Gazelle sensor project, help needed.

Hung Bui — Tue, 21 Mar 2017 10:21:35 GMT

Hi Avi,

The Gazell host has 8 pipes each with different address. You don't need to use the first byte in the payload as the device id if you don't plan to have more than 8 sensors. Each of the sensor communicate with the host via its own "pipe" or address.

To setup the pipe address you can set the base 0 and base 1 and the prefix for each of the address. Please find the addressing policy in the nRF52 spec (BASE0, BASE1, and prefix). In gazell you can use nrf_gzll_set_base_address_0(), nrf_gzll_set_base_address_1() and nrf_gzll_set_address_prefix_byte() to setup the pipes.