DFU buttonless get correct handle for notify but not for write

[Ron]

Hallo

Im trying to get the system into DFU mode from a PC application (not the Nordic connect)

The DFU works perfectly with the Connect application and nordic tools

Im developping a PC GUI and Im able to control all other services,

However when trying to implement the Enter bootloader command I have a problem

it does get the 'enable notifications' correctly with handle 0x19 (which equal to the CCCD Handle)

but when sending a write command it receives it with a 0x18 handle for some reason,

aren't the handle the same ?

for my PC software Im using pygatt and both subscribe (for notification enable) and write use the same uuid - 8e400001-f315-4f60-9fb8-838830daea50

Would appreciate any inputs here

Thanks!

 

[Sigurd]

Hi,

- 8e400001-f315-4f60-9fb8-838830daea50

That does not seem to be correct. Looking at this page, it should be 0x8EC90001-F315-4F60-9FB8-838830DAEA50.

If you are creating your PC application with javascript, you might want to take a look at this repo.

[Ron]

Hi Siguard,
Thanks for your answer,

regarding the UUID, Im using sdk12 so maybe it's different but this is what I have on the ble_dfu.h :#define BLE_DFU_BASE_UUID {{0x50, 0xEA, 0xDA, 0x30, 0x88, 0x83, 0xB8, 0x9F, 0x60, 0x4F, 0x15, 0xF3, 0x00, 0x00, 0x40, 0x8E}} /**< Used vendor specific UUID. */

see also : https://devzone.nordicsemi.com/f/nordic-q-a/17580/implementing-buttonless-dfu-w-sdk12

I couldn't find an equivalent explanation for sdk12 on infocenter,

anyway how would the handle be different between enable notifications and write ?

Thanks again and have a great day

[Sigurd]

Hi,

Yes, the UUID seems to have changed from SDK 12 to SDK 13.

Ron said:

anyway how would the handle be different between enable notifications and write ?

it does get the 'enable notifications' correctly with handle 0x19 (which equal to the CCCD Handle)

but when sending a write command it receives it with a 0x18 handle for some reason,

aren't the handle the same ?

No, the handles are different, so that is as expected. Enable the notification(CCCD handle), and then write 1 to the DFU control point to enter DFU mode.

[Ron]

Hi,

This is what I use for enable notifications and it works :

device.subscribe('8e400001-f315-4f60-9fb8-838830daea50', callback=BlueGigaThread.dfu_event_handler)

and this is what I use for writing :
device.char_write('8e400001-f315-4f60-9fb8-838830daea50',bytearray([1]))
I use the same UUID as I understand that's ok, anyway it doesn't work 

the same synatx worked for other services, but as I say here it arrived with a slightly different handle ..
Any ideas ?
Thanks !

[Sigurd]

Ron said:

it doesn't work

Could you explain what happens when you do this? 

You have programmed the bootloader as well, right?

Ron said:

here it arrived with a slightly different handle

So the write fails ?

If you know the handle, could you try char_write_handle() instead ?

Is wait_for_response set to true or false?