Hello,
Lately we've had some problems with DFU using the NRF connect app.
The device we are using is a nrf52832 running Zephyr 2.6 with MCUBoot 1.8
When we set the following parameters, DFU works fine. The speeds are around 2.6kb/s
CONFIG_BT_L2CAP_TX_MTU=256
CONFIG_BT_BUF_ACL_RX_SIZE=256
If we change these parameters to
CONFIG_BT_L2CAP_TX_MTU=521
CONFIG_BT_BUF_ACL_RX_SIZE=521
(>400 also has the same issue)
the firmware gets uploaded with a speed of about 5kb/s. Once the firmware is sent, and the device reboots to verify the images we get an error that says: "mcuboot swap type none."
from the log in the nrfconnect app we can see that the new firmware image is present, but does not get selected.
This issue does not happen on Iphone since the Iphone automatically negotiates a lower MTU.
This essentially means I have to limit the max MTU of the firmware for the bootloader to work. Are there any workarounds or solutions so that we can use the max DFU?
Kind regards,
Jeroen
