.. _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 using the default flash and debug
mechanisms.

.. note::
   pyOCD added support for KW41Z after support for this board was added to
   Zephyr, so you may need to 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 in the environment before
programming and debugging.

With these mechanisms, applications for the ``frdm_kw41z`` board
configuration can be built and debugged in the usual way (see
:ref:`build_an_application` and :ref:`application_run` for more
details).

Flashing
========

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

Debugging
=========

This example uses the :ref:`hello_world` sample with the
:ref:`nxp_opensda_jlink` tools. Run the following 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.

.. zephyr-app-commands::
   :zephyr-app: samples/hello_world
   :board: frdm_kw41z
   :goals: 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