ARM Board

Revision 1 of the ARM development board

The goal is to have a small, cheap, and powerful development board that supports USB for easy programming, at low parts costs (current estimate < $5). This allows us to use the board for all silly purposes where spending >$20 for an Arduino is just too much. The board is like the Teensy, just with an ARM microcontroller instead.

Quick links

• Project sources
• NUC homepage
• Reference Manual
• ARMv6 Architecture Manual (requires registration)

Detailed Description

The board uses a Nuvoton NUC120 48-pin microcontroller which has an ARM Cortex-M0 CPU 32-bit CPU core.

Features:

• up to 50MHz
• 32KKB-128KKB program flash, 4KKB-16KKB RAM, 4KKB data flash, 4KKB boot loader flash
• 2 UART, 1 SPI, 2 I2C, USB, 1 analog comparator, 4 PWM, 8 12-bit ADC channels

The board contains:

• USB A connector on board outline
• optional Mini-USB receptacle
• USB header connector for direct wire connections (e.g. inside PC)
• optional voltage regulator for external voltage (up to 13V)
• optional LiPo battery charger IC for battery operation
• LiPo charger can be driven from a solar panel
• SWD debug/programming header
• reset button
• 1 LED for binary debug/information display

Project roadmap

Hardware design

In beta state. Version 1 boards have been fabbed and need to be tested and assembled

Errata/changes required for next version:

• probably a problem with 3.3V circuit operation and battery: PMOS gate only gets pulled up to 3.3V, but likely needs the full battery voltage. Replacing PMOS with SOT-323 footprint might help routing.

Toolchain

Proprietary windows software is available, but we'd like to have complete support with free software tools.

What works

• gcc/binutils/gdb support ARM Cortex-M0

In progress

Bus Blaster can speak SWD with KT firmware; use UrJTAG git as root to flash (interface=1). TODO: test SWD connection to target.

What needs work

• Programming/Debugging: OpenOCD supposedly supports SWD. Needs to be confirmed what works.
• Need bootloader and programming software. Proprietary from Nuvoton available
• Tool library?

Programming envionment

• Maple IDE by LeafLabs is a port of the Arduino IDE for ARM
• LeafLabs command-line toolchain might apply in parts, or at least inspire
• summon arm toolchain builds an ARM toolchain

Umbrellas

Eric says: Expansion boards will be called umbrellas.

possible umbrellas:

• sdcard umbrella
• rf umbrella (6LoWPAN/802.15.4?)
• stepper motor umbrella
• lcd umbrella
• microphone umbrella
• speaker umbrella (with small amp)
• power umbrella (bigger voltage regulator)

Example projects

• OTP generator (yubikey-like)
• Your idea here

People involved

Simon