boards: arm: Add Dragino NBSN95 NB-IoT node

# Dragino NBSN95 NB-IoT Sensor Node board configuration

# Copyright (c) 2021 Next Big Thing AG

# SPDX-License-Identifier: Apache-2.0

config BOARD_DRAGINO_NBSN95

	bool "Dragino NBSN95 Sensor Node"

	depends on SOC_STM32L072XX

# Dragino NBSN95 NB-IoT Sensor Node board configuration

# Copyright (c) 2021 Next Big Thing AG

# SPDX-License-Identifier: Apache-2.0

if BOARD_DRAGINO_NBSN95

config BOARD

	default "dragino_nbsn95"

endif # BOARD_DRAGINO_NBSN95

# SPDX-License-Identifier: Apache-2.0

board_runner_args(jlink "--device=STM32L072CZ" "--speed=4000")

include(${ZEPHYR_BASE}/boards/common/openocd.board.cmake)

include(${ZEPHYR_BASE}/boards/common/jlink.board.cmake)

.. _dragino_nbsn95_board:

Dragino NBSN95 NB-IoT Sensor Node

#################################

Overview

********

The Dragino NBSN95 NB-IoT Sensor Node for IoT allows users to develop

applications with NB-IoT connectivity via the Quectel BC95-G.

Dragino NBSN95 enables a wide diversity of applications by exploiting

low-power communication, ARM |reg| Cortex |reg|-M0 core-based

STM32L0 Series features.

This kit provides:

- STM32L072CZ MCU

- Quectel BC95-G NB-IoT

- Expansion connectors:

        - PMOD

- Li/SOCI2 Unchargable Battery

- GPIOs exposed via screw terminals on the carrier board

- Housing

.. image:: img/dragino_nbsn95.png

     :width: 531px

     :align: center

     :height: 354px

     :alt: Dragino NBSN95

More information about the board can be found at the `Dragino NBSN95 website`_.

Hardware

********

The STM32L072CZ SoC provides the following hardware IPs:

- Ultra-low-power (down to 0.29 µA Standby mode and 93 uA/MHz run mode)

- Core: ARM |reg| 32-bit Cortex |reg|-M0+ CPU, frequency up to 32 MHz

- Clock Sources:

        - 1 to 32 MHz crystal oscillator

        - 32 kHz crystal oscillator for RTC (LSE)

        - Internal 16 MHz factory-trimmed RC ( |plusminus| 1%)

        - Internal low-power 37 kHz RC ( |plusminus| 5%)

        - Internal multispeed low-power 65 kHz to 4.2 MHz RC

- RTC with HW calendar, alarms and calibration

- Up to 24 capacitive sensing channels: support touchkey, linear and rotary touch sensors

- 11x timers:

        - 2x 16-bit with up to 4 channels

        - 2x 16-bit with up to 2 channels

        - 1x 16-bit ultra-low-power timer

        - 1x SysTick

        - 1x RTC

        - 2x 16-bit basic for DAC

        - 2x watchdogs (independent/window)

- Up to 84 fast I/Os, most 5 V-tolerant.

- Memories

        - Up to 192 KB Flash, 2 banks read-while-write, proprietary code readout protection

        - Up to 20 KB of SRAM

        - External memory interface for static memories supporting SRAM, PSRAM, NOR and NAND memories

- Rich analog peripherals (independent supply)

        - 1x 12-bit ADC 1.14 MSPS

        - 2x 12-bit DAC

        - 2x ultra-low-power comparators

- 11x communication interfaces

        - USB OTG 2.0 full-speed, LPM and BCD

        - 3x I2C FM+(1 Mbit/s), SMBus/PMBus

        - 4x USARTs (ISO 7816, LIN, IrDA, modem)

        - 6x SPIs (4x SPIs with the Quad SPI)

- 7-channel DMA controller

- True random number generator

- CRC calculation unit, 96-bit unique ID

- Development support: serial wire debug (SWD), JTAG, Embedded Trace Macrocell |trade|

More information about STM32L072CZ can be found here:

        - `STM32L072CZ on www.st.com`_

        - `STM32L0x2 reference manual`_

Supported Features

==================

The Zephyr Dragino NBSN95 Board board configuration supports the following hardware features:

+-----------+------------+-------------------------------------+

| Interface | Controller | Driver/Component                    |

+===========+============+=====================================+

| UART      | on-chip    | serial port-polling;                |

|           |            | serial port-interrupt               |

+-----------+------------+-------------------------------------+

| PINMUX    | on-chip    | pinmux                              |

+-----------+------------+-------------------------------------+

| GPIO      | on-chip    | gpio                                |

+-----------+------------+-------------------------------------+

Other hardware features are not yet supported on this Zephyr port.

The default configuration can be found in the defconfig file:

	``boards/arm/dragino_nbsn95/dragino_nbsn95_defconfig``

Connections and IOs

===================

Dragino NBSN95 Board has GPIO controllers. These controllers are responsible for pin muxing,

input/output, pull-up, etc.

Available pins:

---------------

For detailed information about available pins please refer to `Dragino NBSN95 website`_.

Default Zephyr Peripheral Mapping:

----------------------------------

- UART_1_TX : PB6

- UART_1_RX : PB7

- UART_2_TX : PA2

- UART_2_RX : PA3

System Clock

------------

Dragino NBSN95 System Clock is at 32MHz,

Serial Port

-----------

Dragino NBSN95 board has 2 U(S)ARTs. The Zephyr console output is assigned to UART1.

Default settings are 115200 8N1.

Programming and Debugging

*************************

Applications for the ``dragino_nbsn95`` board configuration can be built and

flashed in the usual way (see :ref:`build_an_application` and

:ref:`application_run` for more details).

Flashing

========

Dragino NBSN95  board requires an external debugger.

Flashing an application to Dragino NBSN95

-----------------------------------------

Here is an example for the :ref:`hello_world` application.

Connect the Dragino NBSN95 to a STLinkV2 to your host computer using the USB port, then

run a serial host program to connect with your board. For example:

.. code-block:: console

   $ minicom -D /dev/ttyACM0

Then build and flash the application:

.. zephyr-app-commands::

   :zephyr-app: samples/hello_world

   :board: dragino_nbsn95

   :goals: build flash

You should see the following message on the console:

.. code-block:: console

   $ Hello World! dragino_nbsn95

Debugging

=========

You can debug an application in the usual way.  Here is an example for the

:ref:`hello_world` application.

.. zephyr-app-commands::

   :zephyr-app: samples/hello_world

   :board: dragino_nbsn95

   :maybe-skip-config:

   :goals: debug

.. _Dragino NBSN95 website:

   https://www.dragino.com/products/nb-iot/item/163-nbsn95.html

.. _STM32L072CZ on www.st.com:

   http://www.st.com/en/microcontrollers/stm32l072cz.html

.. _STM32L0x2 reference manual:

   http://www.st.com/resource/en/reference_manual/DM00108281.pdf