Connection stability with S130

[Marius Heil]

Hello,

has anyone done some good testing on the connection quality between multiple nRF51 chipsets running on the S130 SoftDevice? (Using all four connections, 3 as Central, 1 as Peripheral) Given an environment with very low interferance and a timeout of 6 seconds with a connection interval of 100ms, can the SoftDevice stay in connection for multiple months? I am currently experiencing connection losses at a rather high frequency (about 2-3 per day) and I am wondering wether this is a bug that I introduced somewhere in my code. At times, I receive the BLE_GATTC_EVT_TIMEOUT event which basically forces me to close the connection. But I am wondering why this happens, because both sides process the BLE events quickly.

I guess that Nordic has done quite a bit of testing on connection stability, would you share these results?

Thanks, Marius

Edit: I am initializing the SoftDevice with NRF_CLOCK_LFCLKSRC_XTAL_20_PPM, maybe that is part of the issue, I am currently investigating this.

[Marius Heil]

Hello, thank you. I am currently going over all SoftDevice calls and I am checking my error handling. When I am done, I will have to see if the behaviour remains the same.

I am using S130 v1.0 production, I am using some GAT procedures to build connections, but afterwards, I am using only GATT writes to communicate and connection losses should not occur. I am indeed using scatternets, but I do not have loops. Drift should therefore be carried through the tree.

My current test was only using 8 devices, so I do not think that they chose the same hopping scheme, which is picked randomly as I think?

I will have a look for the NRF_ERROR_BUSY as you propose, but I'll have to understand some of these errors a little better before I handle them, so I will open another Question.

Thank you