In addition to the Arduino team’s Arduino DUE (32-bit ARM based Arduino) rumoured to be released at next week’s Maker Faire …
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
FEZ Panda II
Description: The 72Mhz FEZ Panda II runs .NET Micro Framework, allowing users to program and debug FEZ Panda using Microsoft’s free Visual C# Express. Applications are loaded over USB cable (or serial) with full featured debugging capabilities, such as stepping in code or inspecting variables.
FEZ Panda II is an enhanced version of FEZ Pandawith On-board microSD socket, Real Time Clock, and an easily accessible 40-pin female header that exposes the extra IOs.
FEZ Panda II also includes JTAG access for those who wish to use their own firmware instead of NETMF. Using an Arduino-form-factor, you can use just about any Arduino shield. In addition, many libraries are already included like FAT file system, networking, threading, USB Client, UART, SPI, I2C, GPIO, PWM, ADC, DAC and many more.
The FEZ Panda II includes a USB cable
https://www.sparkfun.com/products/10749
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Netduino Plus
Description: The Netduino Plus is an open source electronics platform using the .NET Micro Framework. The board features a 32-bit microcontroller and a rich development environment, making it a perfect solution for engineers and hobbyists alike.
https://www.mindkits.co.nz/store/development-platforms/dotNET/netduino-plus
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
BugBlat
Bugblat has an entry level development platform for the ARM Cortex M processor in the popular Arduino format and pinout.
The Cortino is USB powered and controlled, so all you need to get started on ARM Cortex development is a Cortino, a USB cable, and a compiler.
The Cortex processor drives the link at 3Mbit/s. As a result you can control the reset mode of the Cortex, rewrite its Flash memory, and drive its serial debug port.
The on-board MCU is an STM32 32-bit ARM Cortex with 32kbyte to 512kbyte program flash, 6kbyte to 64kbyte RAM, up to five USARTs, three SPI, two I2C, six 16-bit timer/counters, three multi-input 12bit ADCs, one 2-channel 12bit DAC, a multi-channel DMA controller, two watchdogs, 5V tolerant I/O, and up to 72MHz operation.
The Arduino format adds multiple expansion headers with 3.3V and 5V available, extends the built-in USB debug interface with an ARM 2×10 pin JTAG connector, and adds flexible reset circuitry and programmable LEDs. The Cortino will operate in both stand-alone mode and as a USB peripheral.
https://www.electronicsweekly.com/products/2008/12/19/20642/bugblat-cortino-cortex-m3-development-system.htm
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Kinetis-L
As Eben Upton has often said, Arduino and Raspberry Pi don’t really compete significantly because they’re so different (maybe just 10% overlap). They should instead be regarded as complementary. When the rather meagre hardware interfacing of the Pi is not enough for your project, combining an Arduino with your Pi will often provide a very effective mix of extensive low-level interfacing and high-level programmability.
However, traditional Arduino boards are based on 8-bit microcontrollers, and although these are perfect for a huge range of applications, there are times when it is desireable to use an ARM microcontroller when interfacing with the Pi’s ARM1176, and not only for ARM symmetry. Some things are simply easier to do with a 32-bit processor, and if processing speed matters in your application then an ARM microcontroller will almost always leave the 8-bit micro way behind.
Unfortunately your options become somewhat limited if you want to use an ARM microcontroller board yet still want to enjoy the ability to use Arduino “shields”, the many hundreds of daughterboards that can plug into an Arduino board’s headers and which make Arduino such a singularly impressive ecosystem. Although the Arduino organization will soon be releasing their own ARM-based Arduino Due using an Atmel SAM3X8E device (a Cortex-M3), it’s not officially out yet (despite having been sighted on flickr), and not many third parties have tackled this empty spot in the market.
The best known are probably the Maple from LeafLabs https://leaflabs.com/devices/maple/ , and the Olimexino-STM32 from Olimex https://www.olimex.com/dev/olimexino-stm32.html which offers quite a lot more and yet is cheaper (£16.96 from Farnell). Both are based on an ARM Cortex-M3 from ST, and offer a degree of Arduino header compatibility.
Well, this area is about to be given an interesting shakeup, courtesy of yet another ARM licensee, Freescale. Their Kinetis KL25Z Freedom Board is now on pre-order at Element 14:
- https://www.element14.com/community/community/knode/dev_platforms_kits/element14_dev_kits/kinetis_kl2_freedom_board
- https://uk.farnell.com/freescale-semiconductor/kl25z128vlk/board-kinetis-l-series-kl25z/dp/2115294?COM=freedompage_knode ,
and you really can’t go wrong at its board price of £8.10 + Arduino header form factor . 
Admittedly the Kinetis KL25Z’s KL2 microcontroller is a Cortex-M0 which is the little brother of the Cortex-M3, but for hardware interfacing that will often be more than ample and is still a huge step up from the 8-bit AVR. What’s more, it’s highly likely to undercut the price of Arduino’s about-to-be-released Arduino Due, so things may get quite interesting in this market niche.
[Added note: the Kinetis KL25Z board uses uses a Cortex-M0+, not M0 — see post 16, https://www.element14.com/community/message/54650#54650 ]
For expanding the Pi (and the BeagleBone too) into the Arduino niche, the Kinetis KL25Z looks extremely good to me. Admittedly, it won’t provide anything like the power of an STM32F4-Discoveryboard which uses a Cortex-M4 https://uk.farnell.com/stmicroelectronics/stm32f4discovery/board-eval-stm32f4-discovery/dp/2009276?Ntt=STM32F4-Discovery , and at £9.96 from Farnell this Discovery is the very clear price-performance leader. However, the Kinetis KL25Z has the Arduino form factor, and that may make all the difference. YMMV !!
Very interesting times ahead! 
And just in case that isn’t tempting enough, ST’s Discovery range has a Cortex-M0 version, the STM32F0-Discovery https://uk.farnell.com/stmicroelectronics/stm32f0discovery/eval-board-cortex-m0-stm32f0/dp/2096251?Ntt=STM32F0-Discovery which is even cheaper at £5.88. If Arduino headers aren’t essential but you want the cheapest possible Cortex-M0 board to expand your Pi, beating £5.88 on sheer price will be very hard. It’s fairly safe to predict that the Cortex-M0[+] range is going to have a colossal impact.
https://www.element14.com/community/thread/18743
Freescale KL25Z freedom board embeds a Kinetis KL25 32-bit MCU based on the new ARM Cortex-M0+ core.
Based on ARM informations, Cortex-M0+ should be more energy efficient (MIPS/mA), fastest I/O and peripheral access and extended system-level capabilities compared to previous Cortex-M0 core version.
Of course each solution has its own strenghs …
Freescale Freedom board includes an additional component (from Kinetis-K family) to manage the debug and the programming of the KL25 M0+ MCU.
Which means that no additionnal hardware tool is needed to evaluate and develop on this board and makes the price really competitive for a complete hardware development tool solution.
Additional comment concerning embedded debugger as it is based on the OpenSDA new standard supporting SWD and JTAG interfaces, in addition debugger also includes a mass-storage bootloader, so users can just copy-paste precompile hex files demo examples from their explorer and reset the board to program the KL25 without any software set-up is required.
Board is compatible with Arduino shields and KL25 is also open to classical ARM Ecosystem (IDE and Firmware Sofware suppliers)
In addition, Freescale offer for FREE its own IDE CodeWarrior (with code-size limitations up to 128KB) , Processor Expert to automate initialization and low-level peripheral driver source code generation and MQX-Lite (RTOS and Stacks).
Detailed informations concerning Freedom board are available on the Knode following the link :https://www.element14.com/community/docs/DOC-46626
~~~~~~~~~~~~~~~~~~~~~~~~~~
LeafLabs Maple
The LeafLabs Maple is a microcontroller board based on the STM32F103RB microprocessor. The Maple runs at a maximum of 72 MHz, has 39 digital input/output pins, 16 analog inputs, native full speed USB, 3 USARTs (hardware serial ports), integrated SPI/I2C support, a power jack, and a reset button. Maple is programmable over USB via our provided DFU bootloader, no extra hardware required! Users can also program the onboard program flash via external JTAG interface. Maple offers security support for read/write protected addresses, as well as User and Handler processor modes. It has a real-time sysTick, useful for a real time OS or any timing senstitive applications. Four built-in 16-bit timers will help you here as well. Maple can be powered via USB, a wall adapter, or it can run off of a rechargeable LiPo battery (see below for more info). The Maple is compatible with shields designed for the Arduino Duemilanove or Diecimila.
https://leaflabs.com/devices/maple/
~~~~~~~~~~~~~~~~~~~~~~~~~~~
Olimexino
FEATURES
- STM32F103RBT6 microcontroller
- DCDC power supply allow power input voltage from 9 to 30V DC thus making possible to take virtually any power supply adapter on the market, also enable application which are in industrial power supply 24VDC.
- carefully selected all components to work reliable in INDUSTRIAL temperature range -25+85C so the board can be used in INDUSTIRAL applications.
- ULTRA LOW POWER voltage regulators and the consumption is only few microamps, which enables handheld and battery powered applications.
- Li-Ion rechargable battery power supply option with BUILD-IN on board charger, so when you attach battery it is automatically charged and kept in this state until the other power source (USB or external adapter) is removed and it AUTOMATICALLY will power the board – no jumpers, no switches!
- UEXT connector which allow many existing modules like RF, ZIGBEE, GSM, GPS to be connected
- allow RTC – Real Time Clock.
- CAN with driver allows automotive applications
- micoSD-card for data logging
- NOISE IMMUNE design.
- Separate voltage regulator for the Analog part, which allow the ADC to be read correctly without the digital noise pickup.
- Optionally if someone need higher precision and temperature stability in Analog reading we have provision on the board for Aref preciese source.
- the LEDs and the BUTTONs are on the edge of the board so there is easy access even if the boards have shields on them
- all components are LOWER than the connectors, so the shields do not interference with them
- mini USB connector is used which is common and used in most cell phones, so you do not have to buy other cables
- original Arduino design had flaw and the connectors were not spaced at 0.1″ this make perfo board use impossible, to keep the compatibility we have same spacing but we add next to this connector on 0.1″ which customer can use with perforated boards
- all signals on the connectors are printed on top and on bottom of the board, so when you check with probe you know exactly which port you are measuring
- 4 mount holes make board attachment easier
https://www.olimex.com/Products/Duino/STM32/OLIMEXINO-STM32/
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Coridium
Features
- Arduino PRO footprint compatible
- Compatible with 5V shields
- FREE tools can be downloaded from the Support Page
- Compiled Integer BASIC runs >10 million lines of codes/sec
- pre-configured ANSI C compiler with floating point
- ARM7 CPU running at 60 Mhz
- Stand-alone operation
- 32K Flash memory and 8K SRAM memory
- 24 TTL compatible digital I/O
- 7 10-bit A/D converters, 100 KHz sample rate
- 8 Hardware PWM channels
- internal supplies of 5V, 3.3V and 1.8V
https://www.coridiumcorp.com/ARMduino.php
~~~~~~~~~~~~~~~~~~~~~~~~~
