Quick connection parameters update

[Ziran]

Hello everyone,

I'm currently trying to change the connection parameters to be quick(100ms 0 slave latency) on a button press and after a timer timeout I go back to the low connection parameters.

I'm also sending a notification to an android application at the same time and then send back 2 characteristic ( LED toggle and a string for a LCD) .

It's working but it take quite a long time (10s) for my application to change the connection parameters so the 2 characteristic are not sent at quick connection parameters the first time but if I press a second time it's then updated and send it quickly.

Do you guys know a workaround this problem ?

[Knut Eldhuset]

Hi,

The Bluetooth spec says that the master should allow a minimum of 6 connection events before the new connection parameters are applied. This could easily amount to 10s, depending on the old connection interval.

You could try using a short connection interval and increasing slave latency to send the notifications more quickly. This would also conserve power.

BR

[Ziran]

Thks for the reply ^^ My "low" connection parameters are 1s for the max interval connection and 3 slave latency . How high could I go for the Slave latency for maximum current economy ?

[Ziran]

i have some other problems now. The first one is that when I change the connection parameters (Smartphone one to my quick ones then quick to slow) I can't change it anymore by calling ble_conn_params_change_conn_params. i do this with a timer that is called each time in BLE_GAP_EVT_CONN_PARAM_UPDATE

the second one is that when I call the change from Quick to slow in the Master control Panel I can see that it's doing 2 same request within 20ms gap and both are accepted(weird).

And the last one is that if after the connection and FIRST_CONN_PARAMS_UPDATE_DELAY is passed I can't change the connection parameters anymore.

for the last one I tought to solve the problem by sending connection parameter update when it's connected .

[Knut Eldhuset]

What do you mean when you say that you can't change the connection parameters? Do you mean that you do the API call successfully, but nothing happens, or do you get an error code from the API call? Please check that you don't get an error code when trying to change parameters.

[Ziran]

In the Log window in the Master Control Panel their is nothing . It's like the call is not done.

[08:44:27.8]Received Connection Parameter Update Request

[08:44:27.8]ConnectionParameterUpdateResponse sent with ACCEPTED response

[08:44:27.8]Connection Parameters Update sent. ConnInterval:100.0ms, SlaveLatency:0, SupervisionTimeout:600.0ms

[08:44:28.3]Received a HandleValueNotification on handle 000E with value 01

[08:44:28.7]Received a HandleValueNotification on handle 000E with value 00

[08:44:38.4] Received Connection Parameter Update Request

[08:44:38.4] ConnectionParameterUpdateResponse sent with ACCEPTED response

[08:44:38.4] Connection Parameters Update sent. ConnInterval:100.0ms, SlaveLatency:0, SupervisionTimeout:600.0ms

[08:44:56.5]Received a HandleValueNotification on handle 000E with value 01

[08:44:56.9] Received a HandleValueNotification on handle 000E with value 00

[Ziran]

So this morning it's worse than yesterday. It's not even sending the good parameters the second time to go back to slow connection parameters . And I've also seen that the button change is called 2 time when pushed and realeased , I don't know why.