Running a first test

Before you start developing, program and run a precompiled application on your development kit to ensure that the kit functions as expected and the communication between your computer and development kit works.

1. Download the Heart Rate Monitor (HRM) demo application from nRF52840 DK Downloads, nRF52833 DK Downloads, or nRF52 DK Downloads and extract it into a folder of your choice.
2. Power up the development kit:
   1. Connect one end of a micro-USB 2.0 cable to the Universal Serial Bus (USB) connector on the kit and the other end to one of your PC's USB host ports.
   2. Slide the power switch to ON.
   
   Observe that LED1 starts blinking.
3. Open a file explorer and confirm that the development kit has appeared as a removable drive named JLINK.
   On Windows, you should see a pop-up window similar to this:

   
4. Copy the HEX file that you downloaded to the JLINK drive.
   The development kit will now restart and run the application. Note that while restarting, the JLINK drive will be disconnected.
5. Download and install the Nordic nRF Toolbox app from Google Play or App Store.
6. Open nRF Toolbox.
   Note: Enable Bluetooth® if prompted.
7. Tap HRM.
8. Tap Connect.
9. Select Nordic_HRS.
   A simulated heart rate and battery charge percentage is displayed.