# 19,842 questions

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## nrf connect indicate subscribe

When I connect to my firmware after cycling Bluetooth on iOS, I am able to subscribe to my Characteristic Indications without any issues. The nRF connect app receives all my my value indications.

After disconnecting, subscribing a second time doesn ... (more)

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## Buttonless DFU - Transfer Succeeds, but no BLE device available after

I'm working the the NRf52 dev board and SDK12.2. I was able to successfully load the standard DFU example and then use the NRF Toolbox on an android to load the example HR zip file to the device ... (more)

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## Problem on dfu_init

I have two boards, one is official demo board, the other I make PCB board.

I down the open-mesh source code form github.sdk version is 8.1,open mesh stack version is 0.8.7

Question, official board I ... (more)

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## can i program nrf51822 bt module using uart

Hi,

I am facing some problem with openocd and stlink connection.

I saw some dve. boards having USB<->serial converter on board for programming (i guess).

So, i got following board.

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## flash nrf51822 using openocd giving error

Hi, I have install openocd on ubuntu. but i after running next line

openocd -f interface/stlink-v2.cfg cfg -f target/nrf51_stlink.tcl


i got these error.

Runtime Error: embedded:startup.tcl:47: Can't find target/nrf51_stlink.tcl
in ...
(more)

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## Radio can not work inside timeslot handler

I'm trying to transmit a radio signal inside time slot handler, the code is like:

  switch (signal_type)
{
}


However, the code is stopped inside the "while(.)" loop ... (more)

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## Change GAP parameters dynamically over a short period

Hi,

I need to be able to change the GAP parameters of my connection for only a short period of time to save battery life but have high throughput when I need it. My firmware will only need to send ... (more)

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## nRF Connect IOS 8.4.1

I'm working with nrf52832 dev board. I used nRF Connect app for IOS but my phone run on IOS8.4.1, so i can't get it from apple appstore. Someone can help me by give version that i ... (more)

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## nRF52840 USB power ???

Could someone explain how to power the nRF52840 via USB?

Looking at the schematics, and also reading the "objective" spec, I can see that VBUS is connected to the USB input bus voltage, and this voltage seems to be used ... (more)

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## One RX and Three TX system with NRF24L01+

This system does not work if I enable the third Pipe (Pipe2) . The system is working without any problem as one RX and two TX (Pipe0 and Pipe1). The problem on enabling Pipe2. According to the data sheet the Pipe2 ... (more)

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## nRFDK Shield Detect

I am considering build some of my own shields to interface with the nRF52DK for the 832 and 840. I am curious how I should use header P5 with the shield detect pin. Should my shield pull this pin low?

Thanks, Darren

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## GPIOTE interrupt count

Hi

I am using nRF51822 (pca10001).I am unable to discover my device. I used the ble_app_template_s130_pca10028 as my base and added the code for gpiote handler as following.

static void gpiote_event_handler(nrf_drv_gpiote_pin_t pin, nrf_gpiote_polarity_t action)

{

int32_t count = 0;
count ...
(more)

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## Problems with BLE Mesh Example

Good day, I tried the BLE Mesh Example located: https://devzone.nordicsemi.com/blogs/...

... and for some reason it is not working for me. I posted a comment where the example is posted, but I have not heard back after ... (more)

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## Eclipse CDT debug and NVIC registers

I'm using Eclipse CDT for debugging according to the tutorial on this site. I've installed the device pack and I do see the nRF52 peripherals in the debug view. However all the general ARM Cortex-M4 peripherals are missing ... (more)

23
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## Precision of TIMER1

Hi there,

I'm using nrf51822 timer1 as the timer for some time-critical task, and I'd like to ask two questions about it:

1. What's the precision of Timer1 if the internal 256K clock is used?

2. If some instructions ...

(more)

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## ADC / PPI: SDK v11.0.0 works but v12.2.0 does not

I was building my own custom application that connects a nrf_drv_timer to an ADC start trigger using PPI on an nRF51822 and I could not get it to work. I asked a previous question about it here. This is a ... (more)

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## Gazell host with multiple devices

I'm new to Gazell, so please excuse the simplicity of my question, but I just seem to be missing something.

I have an application where I will be using one host with two devices. When the host receives a ... (more)

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Hi. Faced with a strange situation. Example. All look good when I read code area:

void ex1 (void)
{
uint32_t i,word;

{
NRF_LOG_INFO("addr %x, word %x ...
(more)

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## NRF52 development kit does not power up

Hello,

I have been using the development kit for more than a month when after one flashing, the LED 5 on the board started blinking at one second intervals and the board froze. After unplugging from the USB and plugging ... (more)

46
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## Full sdk_config.h somewhere?

Using SDK v12.2.0. Starting a new project with Segger Embedded Studio, I have to assemble an sdk_config.h file. For example when using GPIOTE I first need to find an example project that uses it and extract the ... (more)

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## Linker Error Undefined reference to 'something'

I am trying to get nRF52832 working with Segger Embedded Studio. All the examples happily compile and load and run on the board.

But, I want to write my own basic hello world from scratch. So I got the most ... (more)

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## How to log data in Hexadecimal format over nRF Toolbox(UART) android application

Hi,

I'm working on accelerometer + BLE application. My current configurations are nrf51822 and LIS3dh accelerometer chip, Protocol TWI, Softdevice 110, BLE service type is ble_nus_init_t, Android application is UART sub app in nRF Toolbox. At this stage, I can ... (more)

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## Blink questio what are those file do.

Hello, I am new to NRF. and actually i dont have other MCU experience, beside adrduino. my question is not about BLE/BLE+, it's more about how to use NRF5283 in keil question.

I did comple the blynk example ... (more)

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## NRF24L01+ one RX and two or more TX

I am working one one star network system with NRF24L01+. I got success with one pair (Single TX and Single RX) on communicating. But I could not get any positive result for three TX and one RX. I read may ... (more)

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## GPIO interrupt with Proximitty example

Dear Nordic Team,

Thanks for supporting.

currently i am try to interface MMA8453 accelerator with ble proximitty example .Already i have interfaced peripheral example code its working good. But in ble proximitty example code not work because i want to ... (more)

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## app_twi with EasyDMA

Hi, I want to control a g-sensor by nRF52832 via i2c.

I am using an example( nRF5_SDK_12.2.0\examples\ble_peripheral\ble_app_uart\pca10040\s132\arm4) and I add the app_twi into the project.

In the sdk_config.h, I set TWI0_ENABLED ... (more)

69
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## How to debug example pwm_driver? I tried to build debug version make debug but there is no "debug" in make. [closed]

Dear Nordic Engineer,

I need to work on nRF52, my Macbook Air has OSX Yosemite 10.10.5 - I can run "make" or "nrfjprog" only if I copied libjlinkarm.dylib into the same folder that I execute the make or ... (more)

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## 1.4mA in sleep on custom board

We have a custom board using the ISP130301 BLE module (containing a nRF51822, 16MHz xtal, 32kHz xtal). Our apps work fine (gcc, SDK6, S110v7) except for high system on idle power. We are measuring about 1.4mA in sleep using ... (more)

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## NRF52 no emulator connected

I've been through the tutorial of connecting the NRD52 board to my PC, but my PC isnt recognizing it at all. No pop up for any usb devices. I've tried different cables and about 7 different computers, some ... (more)

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## fds.c: m_op_queue.rp uninitialized

i don't see where the command queue index, m_op_queue.rp, is initialized.

when queue_process is called, the following line blows up:

fds_op_t   * const p_op = &m_op_queue.op[m_op_queue.rp];


this occurs when using peer manager and a new device bonds ... (more)

#### Statistics

• Total users: 16310
• Latest user: boon
• Resolved questions: 8512
• Total questions: 19842

## Recent blog posts

• ### nRF52840 long range demo

Posted 2017-02-14 12:46:03 by Ole Bauck
• ### Setup and Running the OpenMesh DFU on the nRF52 DK v2.0

Posted 2017-02-06 22:33:25 by martindavidb
• ### New NFC feature on nRF52 Series: Read/write capable Type 4 Tag NFC library in nRF5 SDK.

Posted 2017-02-02 10:31:31 by Pär H
• ### Simple Application-level Authentication

Posted 2017-01-30 12:34:01 by Daniel Veilleux
• ### WIZnet's BLE to TCP Gateway

Posted 2017-02-01 01:12:03 by Mason Lee

## Recent questions

• ### nrf connect indicate subscribe

Posted 2017-02-20 03:43:55 by Jackson
• ### Buttonless DFU - Transfer Succeeds, but no BLE device available after

Posted 2017-02-20 02:53:04 by TFETT
• ### can i program nrf51822 bt module using uart

Posted 2017-02-19 12:15:29 by phob
• ### Radio can not work inside timeslot handler

Posted 2017-02-19 11:48:10 by JiachengWang
• ### nRF52840 USB power ???

Posted 2017-02-19 11:20:18 by Roger Clark