how to change CC2541 connection period ?

Hi,

The snapshot is not view able in the browser. But generally the connection period consists of the following activities - wakeup, pre processing & packetization of data, RF Rx and Tx. , Post Processing and required event handling, powering down of different domains to prepare to sleep.

Normally the wake up time, RF Rx and Tx time and Power down time are similar except if there are more packets to sent or receive.

The pre and post processing time can vary depending upon the operations you do in the system. So with longer connection interval, the pre and post operations times can vary little bit, but not very significantly(unless you do a lot of processing of data).

Regards,
Arun

Hi Arun,

Thanks for your reply.

Sorry about the snapshot but it shows the connection period as 3.8ms. If I configure the connection parameters in a different way then it goes up to 2.9ms which is a huge difference from my product perspective.

Hence it appears to me that increasing the connection interval also increases the BLE scan interval automatically at link later. I tried to set the following parameters to check if that can change the scan interval but it did not help me.

TGAP_GEN_DISC_SCAN_INT
TGAP_GEN_DISC_SCAN_WIND
TGAP_LIM_DISC_SCAN_INT
TGAP_LIM_DISC_SCAN_WIND
TGAP_CONN_EST_INT_MIN
TGAP_CONN_EST_INT_MAX
TGAP_CONN_EST_MIN_CE_LEN
TGAP_CONN_EST_MAX_CE_LEN

Please let me know if you need further clarification.

Regards,
Vivek

Hi,

Even while the application has not data to send, the Event period can be more than 2.5 ms. And at what value of connection interval do you see such changes? Are you doing any processing of data transfer during these connection events?

Regards,
Arun

Hi,

If I set connection parameters as, min connection interval = 32, maximum connection interval = 48 and slave latency = 0 then connection period is around 3 ms.

But if i change these parameters either by increasing the slave latency or connection intervals so as to get an effective connection interval of 2 secs then the connection period is around 3.7ms or even more.

I am not sending any data, those are just empty connection PDUs.

Regards,

Vivek

Hi,

Even if you are not sending any actual data, Empty connection PDUs will be sent. And because of such long connection interval, the device might process some pending task all at one go, but there should be not much difference in pre and post processing time like you have mentioned. We will have a look at this will get abck to you. I assume youa re using the simpleBLEperipheral example.

Regards,

Arun

Hi,

To be honest, I am not sure what is it that is taking the extra time. It could be the processing time as you said or link layer scanning for more time. But it would be of great help to find out any sort of settings that can reduce the interval.

I am using Keyfob with peripheral configuration.

Regards,
Vivek