Multi packets in SDK 7.2.0 bootloader

[Gili Elias]

Hi, We are doing DFU updates through a nrf51422 dongle (data passing from UART to BLE), using our own code, based on the multilink central example.

The DFU peripherals are nrf51822, s110 7.0.0, SDK 7.2.0. The central unit is nrf51422 dongle, s130 3.0.0, SDK 12.2.0.

We are trying to achieve maximum throughput by using multiple packets per connection interval (@ 7.5 ms interval). It works fine when using a single packet and even two packets per interval, but when increasing to 3 or more, packets seem to get lost, even though TX_COMPLETE event is triggered.

Based on the peripheral SD and SDK, are they suppose to support such throughput?

EDIT: I can't seem to find a way to attach the sniffer trace file. The form allows me to select a file, but doesn't seem to do anything with the file I choose.

Try this link.

This is a trace with a 12 packet notifiaction and 4 packets per connection interval (connection interval set at ~18sec). I stopped it brutally at the middle since it was very slow. The 4 sec breaks are the time we wait for a notification on the central side.

[Gili Elias]

Hi Hung, Thanks for the reply. We used the S130 that came with SDK12.2. You are right, it is 2.0.1. My mistake.

Packet notification was at 100 packets, which didn't work. I've managed to get 4 packets per interval when I set the notification to 4 packets as well, but this slows the throughput (it's takes 2 intervals for 4 writes and a notification).

Does the packet notification indicate that X packets were just received or does it also indicate that they were written to flash?

Is there a way to increase the DFU buffer size?

I'm trying to run a sniffer trace using a PCA10000, but it doesn't seem to work (no data incoming to wireshark). I noticed the sniffer app is pretty old and not maintained. Is it possible it doesn't work with the latest JLink drivers (6.12j)?