Hi dialog,
I come across a problem and wish to have some suggestion about it
I am sending some data to Android phone, but I found out some of the phone cannot receive whole 100Hz of data(huawei P20), result in only having about 80Hz even it have BT4.2.
I use a BLE sniffer tool to sniffer the communication between the phone and DA14681 and only sending a counting number to check discontinuity.
I notice it is not because the phone didn't receive the packet, is DA14681 didn't send the packet continuously, DA14681 will send out the counting number like 1, 2, 4, 5, 7, 8, 9, etc., but this effect will not happen in other Android phone that can receive full 100Hz.
Because I still not very familiar with BLE protocol, is there are any thing I can do about it or minimize this effect? Thank you :)
Hi andoridfm2013,
Could you please try to describe what you are meaning with “100Hz of data” ? Sorry, but I am not able to understand you question, so can you please try to clarify it?
Thanks, PM_Dialog
Hi,
I am sending some data using notify to the phone at 100Hz, which mean 100 packet per second, or 100 notify per second
Hi andoridfm2013,
This depends on the implementation of your application. Can you please let me know which example of the SDK you are using and provide me more details about your application?
Thanks, PM_Dialog
hi,
I am using pxp_reporter example to start, I am read a IMU data using i2C BUS, then send the acc, gyro reading along with some meta data, total about 18 byte to phone by notify at 100Hz, the 100Hz is provide by timer run senddata() function.
The meta data will include a serial number of each packet which is counting upward.
and the problem is some huawei phone always missing some of the packet, upon checking using BLE packet sniffer, DA14681 just skip some of the packet and go missing,
it feels like the phone didn't ACK quick enough so that the DA14681 can send packet continuously then skip some of the packet because timer is keep pushing packet to send out, but I not sure do the notify have ACK at all? so would like to have some insight about this problem, thank you.
Hi andoridfm2013,
If a packet is missing, you will get an invalid crc and then the missing packet will be re-transmitted. As I am able to understand from your description, this issue might be from the side of the phone. Didi you try to use another mobile phone?
Thanks, PM_Dialog