get the min connection interval with 8 sensors

[DavidC]

Hello community,

I did a central device which is connecting with 8 slaves and this slaves are sending every time 8 bytes when they are connected. My set up is the following:

#define MIN_CONNECTION_INTERVAL	MSEC_TO_UNITS(10, UNIT_1_25_MS)	 
#define MAX_CONNECTION_INTERVAL	MSEC_TO_UNITS(16, UNIT_1_25_MS)	
#define SLAVE_LATENCY			0							
#define SUPERVISION_TIMEOUT		MSEC_TO_UNITS(200, UNIT_10_MS)	

But with a timestamp I am getting a connection with each sensor of 30 ms, Also I read on the specification of Nordicm the minimum interval is 20 ms with 8 slaves. How can I do that?

my ble is a NRF 52832 with a SDK 13 version 4.1. and s132

Thanks in advance

[Petter Myhre]

I'm not sure why you get 15 ms, but try to set MIN_CONNECTION_INTERVAL = MAX_CONNECTION_INTERVAL = MSEC_TO_UNITS(16, UNIT_1_25_MS) Then you should get a connection interval of 20 ms, and then you should check the the peripheral isn't requesting to change it. If you are not getting a BLE_GAP_EVT_CONN_PARAM_UPDATE event, you are good.

What do you mean by "these sensors are sending in every package 8 bytes in a connection interval of 30 ms"? The connection interval is independent of how often you send data. Are you using a timer to send one package every 30 ms? How are you sending the data? Notifications? How are you timestamping?

Does it work with only one connection? I would try to get one working first, before scaling to 8.