how to connect to nRF5340 from smart phone?

[woff]

Hello ,I just buy nRF5340 pdk and look at user guide https://infocenter.nordicsemi.com/pdf/getting_started_NCS_nRF53.pdf.
I installed nRF Connect in my PC, and flash HEART HEX to nRF5340.
I installed Nordic nRF Toolbox app in my smart phone for Android OS,
but my phone can't scan nRF5340 PDK devices.
My phone is samsung A8 and HTC U11+ for Android 7.1 .
Please help me, thank you.

[woff]

Where is bliky example.

Please give me URL.

Thank you.

[Nikosant03]

Download the latest SDK.

www.nordicsemi.com/.../Download

Then navigate to examples -> ble_peripherals -> blinky example

infocenter.nordicsemi.com/.../ble_sdk_app_blinky.html

[woff]

I do that, and write nRF5SDK17009d13099\nRF5_SDK_17.0.0_9d13099\components\softdevice\s112\hex

to nRF5340.

But I have problem.

My nRF5340 have logs (

INFO Model: NRF5340_xxAA_ENGA.
2020-08-16T15:06:41.202Z ERROR Error when getting device info: Error: Error: Error occured when open device long term. Errorcode: CouldNotOpenDevice (0x4)
Lowlevel error: INVALID_OPERATION (fffffffe)

2020-08-16T15:06:41.208Z ERROR Error when closing nrfjprog: Error: Error occured when close opened device. Errorcode: CouldNotOpenDevice (0x4)
Lowlevel error: INVALID_OPERATION (fffffffe)

).

I can't write hex to nRF5340 anytime.

How to reset or clear my nRF5340?

help me , thank you.

[woff]

I try to connect reset and Vdd pin. 

I reset com port data.

but it have logs(

2020-08-16T15:34:19.768Z ERROR Error when closing nrfjprog: Error: Error occured when close opened device. Errorcode: CouldNotResetDevice (0x5)
Lowlevel error: CANNOT_CONNECT (fffffff5)

2020-08-16T15:34:19.768Z INFO Model: NRF5340_xxAA_ENGA.
2020-08-16T15:34:19.771Z ERROR Error when getting device info: Error: Error: Error occured when open device long term. Errorcode: CouldNotOpenDevice (0x4)
Lowlevel error: INVALID_OPERATION (fffffffe)

2020-08-16T15:34:19.773Z ERROR Error when closing nrfjprog: Error: Error occured when close opened device. Errorcode: CouldNotOpenDevice (0x4)

)

How to do?

Help me, thank you

[woff]

2020-08-16T15:41:47.896Z INFO Using nrfjprog to communicate with target
2020-08-16T15:41:47.899Z ERROR Could not fetch memory size of target devkit: Error: Error occured when get library info. Errorcode: CouldNotOpenDevice (0x4)
Lowlevel error: INVALID_OPERATION (fffffffe)

[Nikosant03]

I recommend you to follow the Running a first test and Programming an application of Getting started with nRF Connect SDK (nRF53 Series)

Also try to flash your pdk with an example that does not require softdevice.

[woff]

I try to Running a first test and Programming an application of Getting started with nRF Connect SDK (nRF53 Series) many time.

But I can't flash hex to nRF5340 anytime now.

Because I flash wrong hex before.

help me

[Nikosant03]

You're using the programmer (from nRF Connect for Desktop) to flash your board isn't it? Did you try the "Erase all" and then the "Read" to verify that the memory is empty? 

Did you try an example that do not require softdevice?

Also check this post