Deafult Tx Power changed to 0dBm in DTM library since SDK10

RE: Deafult Tx Power changed to 0dBm in DTM library since SDK10

endnode — Fri, 15 Apr 2016 14:42:31 GMT

Hi Hung Bui,

Thanks for the effort, good to know that Nordic at least did it on purpose not by mistake;) I've changed in our code as well as fixing vendor specific commands for actual setting of TXPOWER register during DTM. Still would be better to keep our code in-line with Nordic SDK (because all manual merging during each SDK migration is time consuming) but that's life.

Cheers Jan

RE: Deafult Tx Power changed to 0dBm in DTM library since SDK10

Hung Bui — Fri, 15 Apr 2016 14:21:01 GMT

Hi again Jan,

I understand that the command is from the host to the controller. But in the end, the DTM is to verifiy of the functionalities of a product. I don't see the point of testing something that the product doesn't offer. I just double checked with one of our hardware guys and he said we changed it to 0dBm not by accident and don't think we will change it back to 4dBm.

But as mentioned, you can easy change it back to 4dBm if you like.

RE: Deafult Tx Power changed to 0dBm in DTM library since SDK10

endnode — Fri, 15 Apr 2016 13:04:05 GMT

Hi Hung Bui,

Well this is HCI layer specification, it explicitly speaks about "Controller" and there is really no sign of the application at this stage so it's hard to imagine this interpretation. What if is general multi-app HW and stack being tested/certified? I believe purpose of DTM is quite different then certification of device capabilities in the limits of intended application...

Cheers Jan

RE: Deafult Tx Power changed to 0dBm in DTM library since SDK10

Hung Bui — Fri, 15 Apr 2016 12:52:32 GMT

Hi Jan,

Thanks for pointing out.

I believe it's the maximum output power that the application plans to use. It's not the maximum the radio are capable but the maximum that will be used. Same applied for the frequencies, the radio can operate outside of 2480MHz but we don't have to test that.

We see most of customers don't use +4dBm for transmission and I assume that's the reason we changed the default DEFAULT_TX_POWER. You, of course, can switch it back to +4dBm

RE: Deafult Tx Power changed to 0dBm in DTM library since SDK10

endnode — Fri, 15 Apr 2016 11:57:36 GMT

Hi Hang Bui,

I've updated the question because I cannot put attachment to the comment.

Thanks Jan

RE: Deafult Tx Power changed to 0dBm in DTM library since SDK10

Hung Bui — Fri, 15 Apr 2016 10:45:53 GMT

Hi Jan,

Could you point me into the place in BT Core spec that requires maximum output power when doing DTM ? I actually couldn't find it.