.. _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.jpg
     :align: center
     :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 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:
:zephyr_file:`boards/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:
   https://www.st.com/en/microcontrollers/stm32l072cz.html

.. _STM32L0x2 reference manual:
   https://www.st.com/resource/en/reference_manual/DM00108281.pdf