Extra packet retransmission

Yuri Cherniakov

I have modified the HOGP demo to send mouse notifications to the android OS on my smartphone.

While sending periodic notifications that move the mouse back and forth, every once in a while i get a deviation to the right or left.

It seems that the smartphone ignores one of the messages or receives it twice.

Using the TI packet sniffer i found out this happens after there is an attempt to send a packet and the ACKstatus is not 'OK'.

This can be observed in the attached screen shot of the TI packet sniffer as captured during one of the test.

Also, i attached a log file that might help understand the problem.

4403.HOGP Log 10-04-16 (1).psd

over 8 years ago

0 Zahid Haq over 8 years ago

TI__Mastermind 25035 points

Are you in a noisy environment, if there is other RF activity, it could be that packets are retransmitted if packets are not received in the correct order.

Best wishes

0 Vihang Parmar over 8 years ago

TI__Mastermind 29250 points

Yuri,

The log attached does not have all the samples up to P.nbr. = 7401 that you have highlighted in the screenshot above. Can you please verify that the screenshot is from the same log file?

Best regards,
Vihang

0 Yuri Cherniakov over 8 years ago in reply to Vihang Parmar

Expert 1740 points

Hello!

Thank you for your responses,

Zahid,

The enviroment of the tests is not noisy at all, in fact the only transmission is done by the BT, therefore,

i think this is not the reason.

Vihang,

I will create new sniffer and log files to make sure that they match and post them here.

Thank you,

0 Yuri Cherniakov over 8 years ago in reply to Yuri Cherniakov

Expert 1740 points

Hello Vihang,

As promised here are :

1. new img of the packet sniffer

2. packet sniffer file.

3. logger file

all created at the same experiment.

As can be seen in the image there are two notifications of the same value sent to the android phone.

0 Yuri Cherniakov over 8 years ago in reply to Yuri Cherniakov

Expert 1740 points

Here are the rest of the files.sNIF LOG data.rar

0 Eyal Lahat over 8 years ago in reply to Yuri Cherniakov

Prodigy 100 points

Hi Vihang,

Any ideas with this issues?

Thanks,
Eyal.

0 Vihang Parmar over 8 years ago in reply to Eyal Lahat

TI__Mastermind 29250 points

Hi Eyal, Yuri,

Do you have access to a Bluetooth protocol analyzer with the packet sniffer (Something like FTE or Ellisys)? The TI BLE packet sniffer is good at sniffing and showing the packet data but not much helpful when analyzing different layers of Bluetooth protocols to debug this kind of issue. It would be best to use the protocol analyzer here.

Best regards,
Vihang

P.S. In the latest logs, I am not able to see the same L2CAP data in the saved psd file as you have in the screenshot. I guess something has gone wrong while saving the logs.

0 Yuri Cherniakov over 8 years ago in reply to Vihang Parmar

Expert 1740 points

Hi Vihang,

Unfortunately, i do not have access to these analyzers but i can try and get it.
are there any free ones you know of?

Regarding the logs, This time i recorded the logs at the same time like the packets.
I can do it again if the current logs are not helpful. Do you have any advise regarding the log records?

0 Vihang Parmar over 8 years ago in reply to Yuri Cherniakov

TI__Mastermind 29250 points

Hi Yuri,

Unfortunately, I am not aware of a free HW for bluetooth protocol sniffer.

Regarding the FW logs from TI logger utility, I would like to recommend the following 2 items for the next FW logs.

- Can you start recording logs before the system initializes? This way, the logs include the CC256x initialization commands and everything after it.
- The previous logs had HCI/LMP viewer option enabled, but the BT logger 1 data was not recorded. Can you check both of these options in the settings before recording the next log?

Thanks,
Vihang

0 Yuri Cherniakov over 8 years ago in reply to Vihang Parmar

Expert 1740 points

Hi,

No problem, I will do as you say.

I will have the new logs for you by the end of tomorrow.

0 Yuri Cherniakov over 8 years ago in reply to Yuri Cherniakov

Expert 1740 points

Hello Vihang!

Unfortunately, I haven't had a chance to log the events yet,

I will post the new log as soon as possible,

Yuri.

0 Yuri Cherniakov over 8 years ago in reply to Vihang Parmar

Expert 1740 points

Hello Vihang!

Here is the new log that includes the information you have requested.

This is mouse movement from left to right every 55 milliseconds. i have stopped the logger as soon as i saw serious deviation from the original points

where the mouse appeared. New Log for TI Forum.rar

Bluetooth®︎

Bluetooth forum

Extra packet retransmission