.. _frdm_kw41z:

NXP FRDM-KW41Z
##############

Overview
********

The FRDM-KW41Z is a development kit enabled by the Kinetis |reg| W series
KW41Z/31Z/21Z (KW41Z) family built on ARM |reg| Cortex |reg|-M0+ processor with
integrated 2.4 GHz transceiver supporting Bluetooth |reg| Smart/Bluetooth
|reg| Low Energy
(BLE) v4.2, Generic FSK, IEEE |reg| 802.15.4 and Thread.

The FRDM-KW41Z kit contains two Freedom boards that can be used as a
development board or a shield to connect to a host processor. The FRDM-KW41Z is
form-factor compatible with the Arduino |trade| R3 pin layout for more expansion
options.

The FRDM-KW41Z highly-sensitive, optimized 2.4 GHz radio features a PCB
F-antenna which can be bypassed to test via SMA connection, multiple power
supply options, push/capacitive touch buttons, switches, LEDs and integrated
sensors.

.. image:: frdm_kw41z.jpg
   :width: 720px
   :align: center
   :alt: FRDM-KW41Z

Hardware
********

- Can be configured as Host or Shield for connection to Host Processor
- Supports all DC-DC configurations (Buck, Boost, Bypass)
- PCB inverted F-type antenna
- SMA RF Connector
- RF regulatory certified
- Serial Flash for OTA firmware upgrades
- On board NXP FXOS8700CQ digital sensor, 3D Accelerometer ( |plusminus| 2g/
  |plusminus| 4g/ |plusminus| 8g) + 3D
  Magnetometer
- OpenSDA and JTAG debug

For more information about the KW41Z SoC and FRDM-KW41Z board:

- `KW41Z Website`_
- `KW41Z Datasheet`_
- `KW41Z Reference Manual`_
- `FRDM-KW41Z Website`_
- `FRDM-KW41Z User Guide`_
- `FRDM-KW41Z Schematics`_

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

The frdm_kw41z board configuration supports the following hardware features:

+-----------+------------+-------------------------------------+
| Interface | Controller | Driver/Component                    |
+===========+============+=====================================+
| NVIC      | on-chip    | nested vector interrupt controller  |
+-----------+------------+-------------------------------------+
| SYSTICK   | on-chip    | systick                             |
+-----------+------------+-------------------------------------+
| PINMUX    | on-chip    | pinmux                              |
+-----------+------------+-------------------------------------+
| GPIO      | on-chip    | gpio                                |
+-----------+------------+-------------------------------------+
| I2C       | on-chip    | i2c                                 |
+-----------+------------+-------------------------------------+
| ADC       | on-chip    | adc                                 |
+-----------+------------+-------------------------------------+
| UART      | on-chip    | serial port-polling;                |
|           |            | serial port-interrupt               |
+-----------+------------+-------------------------------------+
| FLASH     | on-chip    | soc flash                           |
+-----------+------------+-------------------------------------+
| SENSOR    | off-chip   | fxos8700 polling:                   |
|           |            | fxos8700 trigger                    |
+-----------+------------+-------------------------------------+

The default configuration can be found in the defconfig file:

	``boards/arm/frdm_kw41z/frdm_kw41z_defconfig``

Other hardware features are not currently supported by the port.

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

The KW41Z SoC has three pairs of pinmux/gpio controllers, but only two are
currently enabled (PORTA/GPIOA and PORTC/GPIOC) for the FRDM-KW41Z board.

+-------+-------------+---------------------------+
| Name  | Function    | Usage                     |
+=======+=============+===========================+
| PTC1  | GPIO        | Red LED / FXOS8700 INT1   |
+-------+-------------+---------------------------+
| PTA19 | GPIO        | Green LED                 |
+-------+-------------+---------------------------+
| PTA18 | GPIO        | Blue LED                  |
+-------+-------------+---------------------------+
| PTB2  | ADC         | ADC0 channel 3            |
+-------+-------------+---------------------------+
| PTC2  | I2C1_SCL    | I2C / FXOS8700            |
+-------+-------------+---------------------------+
| PTC3  | I2C1_SDA    | I2C / FXOS8700            |
+-------+-------------+---------------------------+
| PTC4  | GPIO        | SW3                       |
+-------+-------------+---------------------------+
| PTC5  | GPIO        | SW4                       |
+-------+-------------+---------------------------+
| PTC6  | LPUART0_RX  | UART Console              |
+-------+-------------+---------------------------+
| PTC7  | LPUART0_TX  | UART Console              |
+-------+-------------+---------------------------+

System Clock
============

The KW41Z SoC is configured to use the 32 MHz external oscillator on the board
with the on-chip FLL to generate a 40 MHz system clock.

Serial Port
===========

The KW41Z SoC has one UART, which is used for the console.

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

The FRDM-KW41Z includes the :ref:`nxp_opensda` serial and debug adapter built
into the board to provide debugging, flash programming, and serial
communication over USB.

To use the pyOCD tools with OpenSDA, follow the instructions in the
:ref:`nxp_opensda_pyocd` page using the `DAPLink FRDM-KW41Z Firmware`_. The
pyOCD tools are not the default for this board, therefore it is necessary to
set ``OPENSDA_FW=daplink`` explicitly when you invoke ``make flash`` or ``make
debug``.

.. note::
   pyOCD added support for KW41Z recently and has not yet tagged a release,
   therefore you must build pyOCD from source based on the current master
   branch (f21d43d).

To use the Segger J-Link tools with OpenSDA, follow the instructions in the
:ref:`nxp_opensda_jlink` page using the `Segger J-Link OpenSDA V2.1 Firmware`_.
The Segger J-Link tools are the default for this board, therefore it is not
necessary to set ``OPENSDA_FW=jlink`` explicitly when you invoke ``make
debug``.

Flashing
========

The Segger J-Link firmware does not support command line flashing, therefore
the ``make flash`` build target is not supported.

Debugging
=========

This example uses the :ref:`hello_world` sample with the
:ref:`nxp_opensda_jlink` tools. Use the ``make debug`` build target to build
your Zephyr application, invoke the J-Link GDB server, attach a GDB client, and
program your Zephyr application to flash. It will leave you at a gdb prompt.

.. code-block:: console

   $ cd <zephyr_root_path>
   $ . zephyr-env.sh
   $ cd samples/hello_world/
   $ make BOARD=frdm_kw41z DEBUG_SCRIPT=jlink.sh debug


.. _FRDM-KW41Z Website:
   http://www.nxp.com/products/microcontrollers-and-processors/more-processors/application-specific-mcus-mpus/bluetooth-low-energy-ble/nxp-freedom-development-kit-for-kinetis-kw41z-31z-21z-mcus:FRDM-KW41Z

.. _FRDM-KW41Z User Guide:
   http://www.nxp.com/assets/documents/data/en/user-guides/FRDMKW41ZUG.pdf

.. _FRDM-KW41Z Schematics:
   http://www.nxp.com/assets/downloads/data/en/schematics/FRDM-KW41Z-SCH.pdf

.. _KW41Z Website:
   http://www.nxp.com/products/microcontrollers-and-processors/arm-processors/kinetis-cortex-m-mcus/w-series-wireless-m0-plus-m4/kinetis-kw41z-2.4-ghz-dual-mode-ble-and-802.15.4-wireless-radio-microcontroller-mcu-based-on-arm-cortex-m0-plus-core:KW41Z

.. _KW41Z Datasheet:
   http://www.nxp.com/assets/documents/data/en/data-sheets/MKW41Z512.pdf

.. _KW41Z Reference Manual:
   http://www.nxp.com/assets/documents/data/en/reference-manuals/MKW41Z512RM.pdf

.. _DAPLink FRDM-KW41Z Firmware:
   http://www.nxp.com/assets/downloads/data/en/reference-applications/OpenSDAv2.2_DAPLink_frdmkw41z_rev0241.zip

.. _Segger J-Link OpenSDA V2.1 Firmware:
   https://www.segger.com/downloads/jlink/OpenSDA_V2_1.bin