.. _holyiot_yj16019:

Holyiot YJ-16019
################

Overview
********

The `Holyiot`_ YJ-16019 hardware provides support for the Nordic
Semiconductor nRF52832 ARM Cortex-M4 CPU and the following devices:

* CLOCK
* FLASH
* :abbr:`GPIO (General Purpose Input Output)`
* :abbr:`MPU (Memory Protection Unit)`
* :abbr:`NVIC (Nested Vectored Interrupt Controller)`
* :abbr:`PWM (Pulse Width Modulation)`
* RADIO (Bluetooth Low Energy)
* :abbr:`RTC (nRF RTC System Clock)`
* Segger RTT (RTT Console)
* :abbr:`WDT (Watchdog Timer)`

.. figure:: img/holyiot_yj16019_front.jpg
     :width: 375px
     :align: center
     :alt: Holyiot YJ-16019

     Holyiot YJ-16019 (Credit: Holyiot)

The board is equipped with one LED, one push button, and is powered by
a CR2032 coin cell. The `Nordic Semiconductor Infocenter`_
contains the processor's information and the datasheet.

Hardware
********

The nRF52832 of the Holyiot YJ-16019 is clocked by an external crystal
with a frequency of 32.768 kHz.

Supported Features
==================

The holyiot_yj16019 board configuration supports the following
hardware features:

+-----------+------------+----------------------+
| Interface | Controller | Driver/Component     |
+===========+============+======================+
| CLOCK     | on-chip    | clock_control        |
+-----------+------------+----------------------+
| FLASH     | on-chip    | flash                |
+-----------+------------+----------------------+
| GPIO      | on-chip    | gpio                 |
+-----------+------------+----------------------+
| MPU       | on-chip    | arch/arm             |
+-----------+------------+----------------------+
| NVIC      | on-chip    | arch/arm             |
+-----------+------------+----------------------+
| PWM       | on-chip    | pwm                  |
+-----------+------------+----------------------+
| RADIO     | on-chip    | Bluetooth            |
+-----------+------------+----------------------+
| RTC       | on-chip    | system clock         |
+-----------+------------+----------------------+
| RTT       | Segger     | console              |
+-----------+------------+----------------------+
| WDT       | on-chip    | watchdog             |
+-----------+------------+----------------------+

Other hardware features are not supported by the Zephyr kernel.

Connections and IOs
===================

LED and push button
-------------------

* Push button = P0.28
* LED = P0.29

Programming and Debugging
*************************

Applications for the ``holyiot_yj16019`` board configuration can be
built and flashed in the usual way (see :ref:`build_an_application`
and :ref:`application_run` for more details); however, an external
Segger J-Link is required since the board does not have any on-board
debug IC.

The following pins of the Segger J-Link must be connected to the following test
pads on the PCB (see image):

* VTref = VCC
* GND = GND
* SWDIO = SDO
* SWCLK = SCK

.. figure:: img/holyiot_yj16019_pcb.png
     :width: 390px
     :align: center
     :alt: Holyiot YJ-16019 PCB

     Holyiot YJ-16019 PCB (Credit: Holyiot)

Flashing
========

Follow the instructions in the :ref:`nordic_segger` page to install
and configure all the necessary software. Further information can be
found in :ref:`nordic_segger_flashing`. Then build and flash
applications as usual (see :ref:`build_an_application` and
:ref:`application_run` for more details).

Here is an example for the :ref:`blinky-sample` application.

.. zephyr-app-commands::
   :zephyr-app: samples/basic/blinky
   :board: holyiot_yj16019
   :goals: build flash

Debugging
=========

Refer to the :ref:`nordic_segger` page to learn about debugging Nordic
nRF52x-based boards with a Segger debugger.


Testing the LED and button on the Holyiot YJ-16019
**************************************************

There are 2 samples that allow you to test that the button and LED on
the board are working properly with Zephyr:

.. code-block:: console

   samples/basic/blinky
   samples/basic/button

You can build and flash the examples to make sure Zephyr is running
correctly on your board. The button and LED definitions can be found
in :zephyr_file:`boards/arm/holyiot_yj16019/holyiot_yj16019.dts`.

References
**********

.. target-notes::

.. _Holyiot: http://www.holyiot.com
.. _Nordic Semiconductor Infocenter: https://infocenter.nordicsemi.com