Tomu

Overview

Tomu is a tiny open-hardware board that fits inside a USB Type-A port. It is based on the Silicon Labs EFM32HG309F64 (Happy Gecko), an ARM Cortex-M0+ microcontroller running at up to 24 MHz with 64 KB of flash and 8 KB of SRAM.

Supported Features

The tomu board supports the hardware features listed below.

on-chip / on-board
Feature integrated in the SoC / present on the board.
2 / 2
Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files.
vnd,foo
Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.

tomu/efm32hg309f64 target

Type

Location

Description

Compatible

CPU

on-chip

ARM Cortex-M0+ CPU1

arm,cortex-m0+

Flash controller

on-chip

Silicon Labs Gecko flash controller1

silabs,gecko-flash-controller

GPIO & Headers

on-chip

Silicon Labs Series 0-2 GPIO Peripheral1

silabs,gecko-gpio

on-chip

Silicon Labs Series 0-2 GPIO Port24

silabs,gecko-gpio-port

I2C

on-chip

Silicon Labs Series 0-2 I2C1

silabs,gecko-i2c

Interrupt controller

on-chip

ARMv6-M NVIC (Nested Vectored Interrupt Controller) controller1

arm,v6m-nvic

LED

on-board

Group of GPIO-controlled LEDs1

gpio-leds

MTD

on-chip

Flash node1

soc-nv-flash

Pin control

on-chip

Silabs Gecko Pin Controller1

silabs,gecko-pinctrl

Serial controller

on-chip

Gecko USART2

silabs,gecko-usart

on-chip

Gecko LEUART1

silabs,gecko-leuart

SRAM

on-chip

Generic on-chip SRAM1

mmio-sram

Timer

on-chip

ARMv6-M System Tick1

arm,armv6m-systick

Watchdog

on-chip

Silicon Labs Series 0-2 WDOG1

silabs,gecko-wdog

Programming and Debugging

The tomu board supports the runners and associated west commands listed below.

flash debug
dfu-util ✅ (default)

The Tomu ships with the Toboot [1] USB DFU bootloader. No external programmer is needed; flashing is done over USB using dfu-util.

Flashing

  1. Insert the Tomu into a USB port. The board should enter DFU bootloader mode automatically (red and green LEDs blinking interchangeably).

  2. Build and flash an application:

    # From the root of the zephyr repository
    west build -b tomu samples/basic/blinky
    west flash
    

References