Arturo182 Serpente

Overview

The Serpente is a very small low-cost development and prototyping board equipped with 4MiB flash storage, a PWM enabled RGB led and 6 I/O pins. The board comes with 3 different USB connector options: USB Type-C plug, USB Type-C socket and USB Type-A plug.

Hardware

  • ATSAMD21E18A ARM Cortex-M0+ processor at 48 MHz

  • 256 KiB flash memory and 32 KiB of RAM

  • Extra 4MiB SPI flash memory

  • RGB User LED

  • Reset button

  • Native USB port

Supported Features

The Serpente board configuration supports the following hardware features:

Interface

Controller

Driver/Component

NVIC

on-chip

nested vector interrupt controller

Flash

on-chip

Can be used with LittleFS to store files

SYSTICK

on-chip

systick

WDT

on-chip

Watchdog

GPIO

on-chip

I/O ports

PWM

on-chip

Pulse Width Modulation

USART

on-chip

Serial ports

SPI

on-chip

Serial Peripheral Interface ports

USB

on-chip

USB device

Other hardware features are not currently supported by Zephyr.

The default configuration can be found in the Kconfig file boards/others/serpente/serpente_defconfig.

Connections and IOs

The Serpente documentation [1] has detailed information about the board including pinouts [2] and the schematic [3].

System Clock

The SAMD21 MCU is configured to use the 8MHz internal oscillator with the on-chip PLL generating the 48 MHz system clock.

USB Device Port

The SAMD21 MCU has a USB device port that can be used to communicate with a host PC. See the USB device support sample applications for more, such as the USB CDC-ACM sample which prints “Hello World!” to the host PC.

Programming and Debugging

The Serpente ships the BOSSA compatible UF2 bootloader. The bootloader can be entered by quickly tapping the reset button twice.

Flashing

  1. Build the Zephyr kernel and the Blinky sample application:

    west build -b serpente samples/basic/blinky

  2. Connect the Serpente to your host computer using USB

  3. Tap the reset button twice quickly to enter bootloader mode

  4. Flash the image:

    west build -b serpente samples/basic/blinky
west flash

    You should see the User LED blink.

References