connect inteval time is fixed

[Carey]

i use  the BLE uart example in SDK11.0  to test.  I delete the UART hardware init and just use the BLE send data to phone every 500ms.  I found whatever i set the MIN_CONN_INTERVAL and MAX_CONN_INTERVAL,  the connet interval seems fixed is 50ms.  

I added code to read the connet interval as below:

• static void on_ble_evt(ble_evt_t * p_ble_evt)
  {
  uint32_t err_code;
  
  switch (p_ble_evt->header.evt_id)
  {
  case BLE_GAP_EVT_CONNECTED:

  m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
  
  min_interval=p_ble_evt->evt.gap_evt.params.connected.conn_params.min_conn_interval;
  max_interval=p_ble_evt->evt.gap_evt.params.connected.conn_params.max_conn_interval;

  I have read the connected interval data like this, both of the min_interval and max_interval is 39 (0x27),  despite i set the MIN_CONN_INTERVAL is 350ms, MAX_CONN_INTERVAL is 450ms  ,  

  why?  i want to change the connect inteval ,  How to do is right?

[Einar Thorsrud]

Hi,

The connection interval is set by the central when it connects. The peripheral can request a different connection interval (min and max). How do you do that? The SDK include a Connection Parameters module to help with this, and you can for instance refer to the HRS example to see how it is used.