12 lead ecg system using nRF52832 - huge data loss when phone shake.

[Abhinav Cardea]

Dear experts.. we are trying to build a 12 lead ecg system which sends real time data to mobile phone for plotting using nRF52832. While most of the time it works ok, when we vigorously shake the phone, a huge data loss can be observed. the phone used here is Samsung with BLE 4.2.  I was wondering if that is a normal phenomenon? our sampling rate is 500 samples per second and roughly we are sending 11k byte per  sec.

[Simonr]

Hi

Have you seen this behavior from multiple phones, or just in this one specific Samsung phone? Could you please provide some more details on your test setup? It should not be a problem keeping a throughput of 11kBps per the BLE spec. or on the nRF side of things.

What Samsung phone is this? What Android version is it running? Are you using a specific app for the BLE communication on the phone side?

Are you using an nRF52 DK or custom design? How big is the packet loss you're seeing?

Best regards,

Simon

[Abhinav Cardea]

Hi Simon,

So we have been working to fix the issues and found some ways to optimise our codes and now the packet drops have drastically reduced. However, despite all efforts  we did notice 1-2 packet drops every 2-3 seconds. I was wondering if even that can be avoided to make it lossless transmission. Any thoughts on that?