# 25,465 questions

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## "The 64 MHz crystal oscillator (HFXO) is controlled by a 32 MHz external crystal"- How it works ?

In the nRF52 datasheets there is a statement: "The 64 MHz crystal oscillator (HFXO) is controlled by a 32 MHz external crystal"

Is the crystal somehow oscillating at 2nd harmonic ? is there a frequency doubler?

How much is the oscillation ... (more)

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## Device crashes when debug flags are turned on

I am writing firmware for a BLE Nano device using the Nordic SDK 8.1. I was having problems where my device would suddenly stop printing to UART and stop trying to bond with ble peripherals also. It seems like ... (more)

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## nrf52832 of UART problem

i am using uart of nrf52832. the SDK is nRF5_SDK_12.3.0_d7731ad. the uart is app_uart .when i was testing the uart sending and receing .i find that the uart is stoping where
while (!nrf_uart_event_check(p_instance->reg.p_uart, NRF_UART_EVENT_TXDRDY)) in ...
(more)

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## RTT Stability

Hi

How stable is the RTT module and how trustworthy is it?

It is marked as unstable and I do not get any messages from the modules.

I use:

• #define NRF_LOG_BACKEND_RTT_ENABLED 1
• #define NRF_LOG_ENABLED 1
• #define NRF_SDH_BLE_LOG_ENABLED 1
• #define NRF_SDH_LOG_ENABLED ...
(more)

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## HardFault with GPIOTE & SD

Hi!

I am getting a HardFault when I try to read a GATTs value inside a GPIOTE ISR handler.

I already tried setting the ISR priority to low as suggested in various posts.

Here is my code:

#include "app_settings.h ...
(more)

5
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## adding a service to existing sdk example code

Hello, I am trying to add "experimental_ble_app_blinky" extra service into "ble_app_hids_keyboard" code. Is that possible?

11
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## fds problems sdk14

I'm migrating from sdk13 to sdk14 with work app. Can't solve one weird problem. When my app start first time I initialize some data with saving by fds library to flash. There were no any problem to do ... (more)

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## Calculate time until next RTC Interrupt

Greetings -

I am using (the slightly out-dated) 12.3 SDK with a nRF52840. I'm also using s132 as my softdevice.

As I've been slowly reducing my RTC interrupt frequency to cut down on power consumption, I have a ... (more)

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## Is there a way of capturing 8 GPIOs and transfer data to easydma

Simultaneously, as a way of a parallel bus, using an extra one as a input clock, and save the byte in easydma, without CPU intervention?

Either in the nRF52832 or nRF52840?

Thanks!

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## EVENT_ADDRES and EVENT_END timing on coded phy

Hi,

The tx/rx sequence diagrams don't explain when EVENT_ADDRESS and EVENT_END are triggered when using coded phy:

• there are CI and TERM1 fields between address and S0 so EVENT_ADDRESS is generated directly after address or directly before S0 ...
(more)

18
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## UART interrupt event handling on SDK14.0.0

Hi

I have an application where I cannot use the FIFO buffers (HW or SW). Therefore I need an interrupt for each received byte. If I try to use the uart driver (nrf_drv_uart.c) I have problems enabling the RXDRDY ... (more)

76
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## nRF52832 NRF_ERROR_BUSY from nrf_drv_twi_tx()

i used aplication twi_sensor form nRF5_SDK_12.3.0_d7731ad and i use s132.i conected mpu9060 every time get error on my terminl NRF_ERROR_BUSY.There is exemle of codemain.c and scren from terminal d324ssa42d3434234.png what i do wrong ... (more)

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## Programming an nrf52832 board with ST link V2 and keil issue

Hello,

I've been trying to program my nrf52832 board with an st link v2 dongle or an st32 disco board with no luck with eclipse(Didn't find a dedicated tut for using all) and found keil to maybe ... (more)

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## Can I combine beacon code and HID keyboard code?

I need an application that always advertise the beacon information, such as RSSI and Major and Minor value. At the same time I would like to transmit HID keyboard code. Is it possible to combine these two code? I read ... (more)

11
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## HID Mouse test app for iOS?

Am building a HID Mouse device, starting with the nRF52-DK as hardware target and the BLE peripheral HID mouse sample app. Builds, loads and runs, apparently fine (i.e., can see target advertising with LightBlue app on an iPhone 6S ... (more)

18
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1

## SDK 14 Makefile.common missing

I am trying to compile the blinky example in the SDK 14.

I am getting this error:

makefile:111: ../../../../../../components/toolchain/gcc/Makefile.common: No such file or directory

this directory is actually empty. I remember in SDK 11 this ... (more)

55
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## Application file encryption (.bin)

Hello we would like to upload to the cloud the nrfutil generated zip package, however we are worried about the application file security. As far as we know, nrfutils takes the unencrypted .hex file and generates signature in order to ... (more)

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## how to enter "power down" mode in nrf52832

Hello,

I was using the nrf24LE1 where i used hal_nrf_set_power_mode() to set the radios' power down mode. Options are power-up and power-down. This is when i was using the HAL_NRF library.

Now I am migrating functionality to the nrf52832 in ... (more)

11
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nRF52832 SDK14.0

Hi, how can I protect the bootloader from being overwritten? Ideally, I would never be updating the bootloader so it will be a permanent part of the device. How can I make sure nothing can overwrite/erase ... (more)

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## Issue using NRF_DRV_TWI_XFER_DESC_TXRX TWI master driver

At the very end of this post from Nordic Info center I am doing the exact example at the very end.

http://infocenter.nordicsemi.com/inde...

This is the start to do a transmit read transaction ===>

nrf_drv_twi_xfer_desc_t xfer = NRF_DRV_TWI_XFER_DESC_TXRX(addr ... (more)

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## Fstorage - fs_erase causes connection failure

Hello,

I'm encountering a very strange problem while attempting to run an fstorage fs_erase operation on my peripheral device when the central is connected. This is on a nRF52832, SDK 12.1.0, SoftDevice S132 v3.0.0 and ... (more)

1k
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## Programming external/custom NRF52832 board using NRF52-DK

Hi All,

We are trying to flash our custom NRF52832 board using NRF52-DK+nrf studio. With the same setup that's suggested by https://devzone.nordicsemi.com/questi...

However, from the nrf studio, we can never see the external board ... (more)

15
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## how to arm cross compile pc-ble-driver

Hi all,

I would like to know how to cross compile the pc-ble-driver-py for arm target. Do you please have a prooceding tutorial for this activity?

Thanks in advance and best regards,

33
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## Usage of Nordic Semiconductors proprietary UART service for commercial products

As stated in the topic. We use BLE to simulate UART. As for now, we have defined our own UUIDs but there would be more straight forward to use the well defined and used one by Nordic. However, is it ... (more)

38
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## light control mesh example not working

I'm trying to set up a ble mesh with 3 servers and 1 client on an nrf52 PCA10040 dev kit. Upon debugging, I'm getting an error that says: '64, APP_ERROR: C:\Users\sesa463145\Desktop\BLE\nrf5_SDK_for_Mesh_v0.9.2-Alpha ... (more)

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## Application compiles with no errors but still dosen't work?

I am building a Bluetooth Mesh application based on the Mesh Beacon Example, i have written a custom Makefile and got it compiling with no errors.

But when Flashing the nRF51422 with the program, nothing happens. If I build the ... (more)

18
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1

## uECC.h no such file or directory even after proper installation of microecc library

Hi, I have installed Software backend (micro-ecc) as given in: https://infocenter.nordicsemi.com/ind...

Compiled example: experimental/ble_app_multirole_lesc --> compilation is successful here.

Now i am want to include and use microecc library in my own example, I have modified ... (more)

36
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## SDK 14 buttonless dfu not building with gcc

I'm using SDK 14 and trying to build the ble_app_buttonless_dfu example. I'm using Linux environment, so gcc for building. When I try to build the example I'm getting an error as below,

Compiling file: ble_dfu_unbonded.c
/tmp ...
(more)

28
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Hi, (I'm a computer scientist, please be kind)

In the below attached image, I have collected the data outdoors (so no signal reflection or signal fading) from a single BLE beacon at two different pre-set power levels. I see ... (more)

28
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## Printf on 52840 causes Hard Fault in _Balloc

Hey there,

I'm using the nRF52840 and have all sorts of problems trying to using dynamic memory allocation. I'm trying to develop on an example project from ./examples/ble_peripheral/ble_app_uart. Firstly I had to modify the project because ... (more)

#### Statistics

• Total users: 24452
• Latest user: Sven Nealey
• Resolved questions: 10451
• Total questions: 25466

## Recent blog posts

• ### 6 Things to Know about Bluetooth Beacons

Posted 2017-09-22 08:27:00 by Rose Martin
• ### Creating a Keil project for a Bluetooth Mesh example

Posted 2017-09-19 12:08:11 by Kristian Skordal
• ### Using millis() like in Arduino.

Posted 2017-09-18 11:58:04 by schef
• ### Flashing nRF5x firmware using any dumb terminal program via standard serial COM port

Posted 2017-09-18 03:53:40 by Nguyen Hoan Hoang
• ### How to Debug the nRF52 Interrupts — Useful Tips

Posted 2017-09-13 15:15:22 by Yaniv Nis

## Recent questions

• ### Device crashes when debug flags are turned on

Posted 2017-09-24 04:09:33 by tyler
• ### nrf52832 of UART problem

Posted 2017-09-24 04:05:27 by lenli
• ### RTT Stability

Posted 2017-09-24 03:28:49 by Yatekii
• ### HardFault with GPIOTE & SD

Posted 2017-09-24 03:18:09 by Yatekii
• ### adding a service to existing sdk example code

Posted 2017-09-24 02:45:24 by alikob