MCP and phone visibility

[Ondrej Meca]

Hi,

We are developing weareble with nrf52832 and already made 6 test modules. Everythink works fine except 1 module. This wonderful piece is visible only on PC Win 10 (MCP or our custom testing app). But thats all, this device is not visible to phones or any other (Apple not tested). All modules are identical.

Any suggestions ?

Thanks for help. Ondřej Meca

[endnode]

Ahoj Ondřeji,

Have you tried some radio sniffer (e.g. Nordic sniffer on nRF51 or 52 DK?) These devices are typically well inert to any caching or filtering issues so they see all (or nothing if really broken). Otherwise hard to say what could confuse Android phones so they would miss your broadcasts but MCP on Windows sees it. If you can afford it the reset network setting on test phones (this is easier on iOS devices - although there it wipes all network setting including WiFi and other - while on Android it might depend on HW manufacturer and Android versions/customs, typically wiping data and cache from "BT Share" process is good start).

Cheers Jan

[Ondrej Meca]

Hi, thanks for quick response.

I tried visibility of that device on new phones that they were not used and device is still not visible.

Also I tried to sniff something. I dont see any difference. Here are results.

Visible device.

Invisbile device

[endnode]

But you have "LE Limited Discoverable Mode: true" in AD Flags element, couldn't that be a problem? To be honest I never use this mode and even BT SIG specification suggests that any GAP Central should report these packets as received to higher layers I wouldn't be surprised.

[FormerMember]

It could be that the carrier frequency is not correct, that it is a little off of what is normally. Do you have a spectrum analyzer available? If so, you could disconnect the antenna and connect to the spectrum analyzer instead, program the radio_test example to the chip, and measure the center frequency for a given channel.

The load capacitors of the 16 MHz crystal affects the center frequency, you could for example double check that the mounted capacitors are the correct ones. The formula in section "Crystal and load capacitors", can be used to calculate appropriate value for the capacitors.