Converting BLE_peripheral UART example to support 4 peripheral connections

[A sudheer Kumar]

Hi All,

I modified ble_peripheral UART example to support 4 peripheral links instead of one by referring the bel_app_multiperipheral example, I am able to connect four mobiles(central devices) to it and sending (from central devices ) some strings successfully to peripheral.

now question is how to replay from peripheral to all central devices? actually I tried with below function to send the strings from peripheral to central devices

void vfnSendSensorResponsOnBle(uint8_t *ptr, uint32_t len)
{
         uint8_t uIndex = 0;
         uint32_t err_code = 0;
    

         for (uint32_t i = 0; i < NRF_SDH_BLE_PERIPHERAL_LINK_COUNT; i++)
         {
              if (m_qwr[i].conn_handle != BLE_CONN_HANDLE_INVALID)
              {
                     NRF_LOG_DEBUG("Ready to send data over BLE NUS");

                    do
                   {
                        if(len>20)
                           len=19;

                       err_code = ble_nus_data_send(&m_nus, ptr, (uint16_t *)&len, m_qwr[i].conn_handle/*m_conn_handle*/);
                       if ((err_code != NRF_ERROR_INVALID_STATE) &&
                          (err_code != NRF_ERROR_RESOURCES) &&
                          (err_code != NRF_ERROR_NOT_FOUND))
                          {
                               APP_ERROR_CHECK(err_code);
                          }

                   } while (err_code == NRF_ERROR_RESOURCES);
              }
         }
}

with the above function able to send strings from peripheral to central when one central device is connected. when I tried the same with more than once central connections, peripheral device getting restarted.

Here I am not getting what causing for it, I think  need to modify above function. 

Please let me know what are the things need to be change or any example for reference other than  bel_app_multiperipheral.

Thanks in Advance

Regards,

Sudheer 

[Susheel Nuguru]

I believe there was some requests similar to this before in devzone. Have you tried to search for them here?

In the nutshell, it is possible, but need some changes to the ble_nus module. You need to make changes to the Nordic UART service data structures to handle multi instance connections. At the moment, it is a single connection only module (out of the box)

[A sudheer Kumar]

Hi Susheel,

Thanks for your reply, 

I searched in Devzone, but didn't get any related links regarding my issue. If you have any, please share us.

 You need to make changes to the Nordic UART service data structures to handle multi instance connections. At the moment, it is a single connection only module (out of the box)

 what are the changes need do, which example will help me to solve this issue 

Regards,

Sudheer

[Susheel Nuguru]

If you are looking for a NUS central that can support multiple peripherals, you can try to look at this github project.

[A sudheer Kumar]

thanks for the example,

Actually I am looking for NUS peripheral that can support multiple centrals 

[Susheel Nuguru]

I might have done this as a hobby project few years back but unfortunately I cannot find traces of it.

It is definitely possible to modify the example and ble_nus module to handle multiple connections with central, and could be done in a week effort. But unfortunately, I cannot help with the code, sorry.

[A sudheer Kumar]

thanks for your reply