NRF8001 module connection problem

RE: NRF8001 module connection problem

tilitililili — Thu, 14 Jul 2016 08:17:32 GMT

I've discovered a lot of interesting things =) I provided experiments with two boards - my own (let's call it board_1) and dev. board (board_2), which I've bought. 1.board_2 shows the same performance with shunt capacitor mounted or removed. The level is (-60 - -100 dbm) and the range is 0 - 200 cm. 2.board_1 shows the same characteristics as board_2 with antenna disconnected (!) - C12 removed. 3.With shunt capacitor removed (on board_1) I get a zone (10cm - 100cm), where board cannot be discovered by the application. But the level in 0cm-10cm zone is -20 dbm. 4.With C43 mounted board_1 works worse. 5.Seems like board_1 works better with shunt inductor instead of shunt capacitor. I haven't tested it fully yet. So, seems like the problem is not in my board - it's in board_2... Board_1 shows better range. The only problem is zone 10cm-100cm, I don't understand why the signal disappears.

RE: NRF8001 module connection problem

Øyvind Karlsen — Thu, 14 Jul 2016 05:52:58 GMT

If it performs the same when mounted or removed, that's a bad sign. Please submit a ticket to MyPage to get in touch with our RF engineers for assistance with RF tuning.

RE: NRF8001 module connection problem

tilitililili — Wed, 13 Jul 2016 15:47:41 GMT

There is nothing special in this room, no metal walls etc. Just a simple room. The board was tested in different places and the results were the same. Unfortunately, there is no equipment to measure the SWR ( I tried some experiments with C43 - when it is mounted the behavior is the same as if it is removed...

RE: NRF8001 module connection problem

Øyvind Karlsen — Wed, 13 Jul 2016 10:45:16 GMT

OK. Is there anything particular about the room you are measuring in (metal walls etc)?

For antenna matching you use a shunt capacitor, C43. Are you sure that the antenna resonates so that C43 is the only needed component in the Pi network? (If you are not sure, check the antenna SWR with C43 removed has a minimum for the desired frequency)

RE: NRF8001 module connection problem

tilitililili — Wed, 13 Jul 2016 10:37:32 GMT

Sorry, I don't understand what setup do you mean... To measure the range I just follow these steps:

Launch android application
Try to discover the board
Put the phone in another place
Repeat step 2.

RE: NRF8001 module connection problem

Øyvind Karlsen — Wed, 13 Jul 2016 10:27:31 GMT

I meant pictures of the range measurement setup

RE: NRF8001 module connection problem

tilitililili — Wed, 13 Jul 2016 09:33:06 GMT

schematic - drive.google.com/.../view

Did you mean it?..

C43 isn't mounted and C3, C4 are 15 pF in current version.

RE: NRF8001 module connection problem

Øyvind Karlsen — Wed, 13 Jul 2016 05:59:55 GMT

I meant the physical setup

RE: NRF8001 module connection problem

tilitililili — Tue, 12 Jul 2016 19:00:04 GMT

Here are the images of the NRFgo studio settings - drive.google.com/.../view drive.google.com/.../view

But the settings are the same for both boards, and one of them works perfect...

RE: NRF8001 module connection problem

Øyvind Karlsen — Mon, 11 Jul 2016 06:31:19 GMT

Could you provide some images of your test setup?

RE: NRF8001 module connection problem

tilitililili — Fri, 08 Jul 2016 13:45:58 GMT

Yes, of course. I placed it between 26 and 29 - AVDD line.

RE: NRF8001 module connection problem

Øyvind Karlsen — Fri, 08 Jul 2016 13:26:29 GMT

Yes I meant 29, sorry. Was that were you added the wire?

RE: NRF8001 module connection problem

tilitililili — Fri, 08 Jul 2016 10:50:42 GMT

I've tried to add an external wire, but nothing changed...

RE: NRF8001 module connection problem

tilitililili — Fri, 08 Jul 2016 10:35:12 GMT

28 is XC1 pin (external crystal). Maybe you talk about 26 and 29? I thought these pins are connected inside the chip... Aren't they?

RE: NRF8001 module connection problem

Øyvind Karlsen — Fri, 08 Jul 2016 07:57:30 GMT

Hi,

You are missing a connection to AVDD on pin 26, try soldering a short wire from pin 26 to pin 28 and see if that helps.

RE: NRF8001 module connection problem

tilitililili — Thu, 07 Jul 2016 18:39:28 GMT

I have only one board and the development board with NRF8001 module (MOD-nRF8001). The development board works fine...

In 0-10 cm - RSSI = -25-35 Beyond 100 cm - near -80-90

RE: NRF8001 module connection problem

Øyvind Karlsen — Wed, 06 Jul 2016 10:45:28 GMT

Does the same thing happen to all the boards or just the one?

What kind of RSSI values are you seeing in 0-10 cm and beyond 100 cm?

RE: NRF8001 module connection problem

tilitililili — Wed, 06 Jul 2016 09:43:58 GMT

Pin 15 is unconnected, and this "track' is a part of the ground polygon.

RE: NRF8001 module connection problem

Øyvind Karlsen — Wed, 06 Jul 2016 09:31:06 GMT

Is there any reason that the track to pin 15 is cut?

What environment are you seeing this in?

RE: NRF8001 module connection problem

tilitililili — Wed, 06 Jul 2016 09:14:28 GMT

Here is the layout screenshot - drive.google.com/open I'm testing the connection with NRF control panel application on my phone.

RE: NRF8001 module connection problem

Øyvind Karlsen — Wed, 06 Jul 2016 08:37:05 GMT

Hi,

How are you testing this?

Could you submit your layout?