.. _efm32pg_stk3401a:

EFM32 Pearl Gecko Starter Kit
#############################

Overview
********

The EFM32 Pearl Gecko Starter Kit EFM32PG-STK3401A contains an MCU from the
EFM32PG family built on an ARM® Cortex®-M4F processor with excellent low
power capabilities.

.. figure:: ./efm32pg_stk3401a.jpg
   :width: 375px
   :align: center
   :alt: EFM32PG-SLSTK3401A

   EFM32PG-SLSTK3401A (image courtesy of Silicon Labs)

Hardware
********

- Advanced Energy Monitoring provides real-time information about the energy
  consumption of an application or prototype design.
- Ultra low power 128x128 pixel Memory-LCD
- 2 user buttons, 2 LEDs and 2 capacitive buttons
- Humidity and temperature sensor
- On-board Segger J-Link USB debugger

For more information about the EFM32PG SoC and EFM32PG-STK3401A board:

- `EFM32PG Website`_
- `EFM32PG1 Datasheet`_
- `EFM32PG1 Reference Manual`_
- `EFM32PG-STK3401A Website`_
- `EFM32PG-STK3401A User Guide`_

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

The efm32pg_stk3401a board configuration supports the following hardware features:

+-----------+------------+-------------------------------------+
| Interface | Controller | Driver/Component                    |
+===========+============+=====================================+
| MPU       | on-chip    | memory protection unit              |
+-----------+------------+-------------------------------------+
| NVIC      | on-chip    | nested vector interrupt controller  |
+-----------+------------+-------------------------------------+
| SYSTICK   | on-chip    | systick                             |
+-----------+------------+-------------------------------------+
| COUNTER   | on-chip    | rtcc                                |
+-----------+------------+-------------------------------------+
| FLASH     | on-chip    | flash memory                        |
+-----------+------------+-------------------------------------+
| GPIO      | on-chip    | gpio                                |
+-----------+------------+-------------------------------------+
| UART      | on-chip    | serial port-polling;                |
|           |            | serial port-interrupt               |
+-----------+------------+-------------------------------------+
| I2C       | on-chip    | i2c port-polling                    |
+-----------+------------+-------------------------------------+
| WATCHDOG  | on-chip    | watchdog                            |
+-----------+------------+-------------------------------------+

The default configuration can be found in the defconfig file:

	``boards/arm/efm32pg_stk3401a/efm32pg_stk3401a_defconfig``

Other hardware features are currently not supported by the port.

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

The EFM32PG1 SoC has five GPIO controllers (PORTA to PORTD and PORTF) and
all are enabled for the EFM32PG-STK3401A board.

In the following table, the column **Name** contains pin names. For example, PF4
means pin number 4 on PORTF, as used in the board's datasheets and manuals.

+-------+-------------+-------------------------------------+
| Name  | Function    | Usage                               |
+=======+=============+=====================================+
| PF4   | GPIO        | LED0                                |
+-------+-------------+-------------------------------------+
| PF5   | GPIO        | LED1                                |
+-------+-------------+-------------------------------------+
| PF6   | GPIO        | Push Button PB0                     |
+-------+-------------+-------------------------------------+
| PF7   | GPIO        | Push Button PB1                     |
+-------+-------------+-------------------------------------+
| PA5   | GPIO        | Board Controller Enable             |
|       |             | EFM_BC_EN                           |
+-------+-------------+-------------------------------------+
| PA0   | UART_TX     | UART TX Console VCOM_TX US0_TX #0   |
+-------+-------------+-------------------------------------+
| PA1   | UART_RX     | UART RX Console VCOM_RX US0_RX #0   |
+-------+-------------+-------------------------------------+
| PD10  | UART_TX     | EXP12_UART_TX LEU0_TX #18           |
+-------+-------------+-------------------------------------+
| PD11  | UART_RX     | EXP14_UART_RX LEU0_RX #18           |
+-------+-------------+-------------------------------------+
| PC10  | I2C_SDA     | ENV_I2C_SDA I2C0_SDA #15            |
+-------+-------------+-------------------------------------+
| PC11  | I2C_SCL     | ENV_I2C_SCL I2C0_SCL #15            |
+-------+-------------+-------------------------------------+


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

The EFM32PG SoC is configured to use the 40 MHz external oscillator on the
board.

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

The EFM32PG SoC has two USARTs and one Low Energy UART (LEUART).

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

.. note::
   Before using the kit the first time, you should update the J-Link firmware
   from `J-Link-Downloads`_

Flashing
========

The EFM32PG-STK3401A includes an `J-Link`_ serial and debug adaptor built into the
board. The adaptor provides:

- A USB connection to the host computer, which exposes a mass storage device and a
  USB serial port.
- A serial flash device, which implements the USB flash disk file storage.
- A physical UART connection which is relayed over interface USB serial port.

Flashing an application to EFM32PG-STK3401A
-------------------------------------------

The sample application :ref:`hello_world` is used for this example.
Build the Zephyr kernel and application:

.. zephyr-app-commands::
   :zephyr-app: samples/hello_world
   :board: efm32pg_stk3401a
   :goals: build

Connect the EFM32PG-STK3401A to your host computer using the USB port and you
should see a USB connection which exposes a mass storage device(STK3401A).
Copy the generated zephyr.bin to the STK3401A drive.

Use a USB-to-UART converter such as an FT232/CP2102 to connect to the UART on the
expansion header.

Open a serial terminal (minicom, putty, etc.) with the following settings:

- Speed: 115200
- Data: 8 bits
- Parity: None
- Stop bits: 1

Reset the board and you'll see the following message on the corresponding serial port
terminal session:

.. code-block:: console

   Hello World! arm


.. _EFM32PG-STK3401A Website:
   https://www.silabs.com/development-tools/mcu/32-bit/efm32pg1-starter-kit

.. _EFM32PG-STK3401A User Guide:
   https://www.silabs.com/documents/public/user-guides/ug154-stk3401-user-guide.pdf

.. _EFM32PG Website:
   https://www.silabs.com/products/mcu/32-bit/efm32-pearl-gecko

.. _EFM32PG1 Datasheet:
   https://www.silabs.com/documents/public/data-sheets/efm32pg1-datasheet.pdf

.. _EFM32PG1 Reference Manual:
   https://www.silabs.com/documents/public/reference-manuals/efm32pg1-rm.pdf

.. _J-Link:
   https://www.segger.com/jlink-debug-probes.html

.. _J-Link-Downloads:
   https://www.segger.com/downloads/jlink