Setting MIN MAX CONN_INTERVAL

RE: Setting MIN MAX CONN_INTERVAL

James Yu — Thu, 09 Jun 2016 15:24:44 GMT

The actual connection parameters would be decided by central in that case. In your on_ble_evt() handler you can look for the BLE_GAP_EVT_CONN_PARAM_UPDATE event. You can get the settings from the ble_evt_t struct: p_ble_evt->evt.gap_evt.params.conn_param_update

RE: Setting MIN MAX CONN_INTERVAL

Minh — Thu, 09 Jun 2016 04:33:48 GMT

Ah, I see. So do you what is real connection interval value if 3-rd condition is not satisfied ?

RE: Setting MIN MAX CONN_INTERVAL

James Yu — Thu, 09 Jun 2016 04:30:21 GMT

I think that's an typo, it should just be Interval Max, and slave latency should be a separate point.

RE: Setting MIN MAX CONN_INTERVAL

Minh — Thu, 09 Jun 2016 01:17:37 GMT

What is Interval Max Slave Latency ? is it same as Interval Max ? if yes, why do they call it Interval Max Slave Latency ?

RE: Setting MIN MAX CONN_INTERVAL

James Yu — Wed, 08 Jun 2016 20:18:05 GMT

Take a look at Apple's Bluetooth Design Guidelines: developer.apple.com/.../BluetoothDesignGuidelines.pdf

3.6 Connection Parameters
The accessory isresponsible for the connection parameters used for the Low Energy connection. The accessory
should request connection parameters appropriate for its use case by sending an L2CAP Connection Parameter
Update Request at the appropriate time. See the Bluetooth 4.0 specification, Volume 3, Part A, Section 4.20 for
details. The connection parameter request may be rejected if it does not comply with all of these rules:
● Interval Max * (Slave Latency + 1) ≤ 2 seconds
● Interval Min ≥ 20 ms
● Interval Min + 20 ms ≤ Interval Max Slave Latency ≤ 4
● connSupervisionTimeout ≤ 6 seconds
● Interval Max * (Slave Latency + 1) * 3 < connSupervisionTimeout

So if MIN_CONN_INTERVAL = MAX_CONN_INTERVAL, it could be rejected since it doesn't satisfy #3

RE: Setting MIN MAX CONN_INTERVAL

Anders Strand — Wed, 08 Jun 2016 15:09:30 GMT

Hi. The connection interval is in reality decided by the central device (the phone). The peripheral device can request a certain interval, but the central does not have to accept it. Do you have an extra nRF51 you can set up as an nRF sniffer and capture the connection event?