BC68 CoAP Block1/2 OPTIONS


the AT+QCOAPOPTION command allows setting of several different CoAP options. We need to use the Block1 and Block2 options in order to support CoAP block-wise transfers in upstream (Block1) and downstream (Block2) directions.
We cannot find the proper way to set values for NUM, M and SZX fields of option value (see https://tools.ietf.org/html/rfc7959). It seems that only NUM field is taken from AT+QCOAPOPTION option value, but M bit always stay to 0 (no more blocks) and SZX field always stay to 5 (Block size 512 bytes).

How can I set all fields (NUM,M,SZX) of Block1/2 options using the AT command AT+QCOAPOPTION?

The BC68 Firmware Release Notes for the R01A10 firmware says that
“Added new feature for AT+QCOAPOPTION command to support setting the custom option.”
But the AT command manual isn’t updated with such change.
How we can set CoAP custom option using AT+QCOAPOPTION command on R01A10 firmware?

Hi Paolo
The current latest firmware block1/2 does not support very well and may not meet your current requirements.
The size is fixed at 512, and the more is fixed at 0, so no change is supported.

Hi Abner,
do you plan to fix these restrictions that make block1/2 options useless on BC68?
I think that the best way may be to use raw values from AT+QCOAPOPTION without hadling separated fields like NUM, M and SZX. Left block1/2 option binary filelds encoding to host application and put raw values from user command to block1/2 options value keeping in mind that the option size may be from 1 to 3 bytes based on its value.

Do you think it’s possible to do?

It seems that CoAP Options on receive side dont work properly, please check my recent post BC68 missing CoAP OPTIONS in response URC

Hi Paolo
currently, there is no schedule to solve this problem.

Thanks Abner

it seems that BC68 CoAP stack isn’t ready for a real and professional usage…
We will work to integrate libcoap to work on top of UDP stack