.NET softwired

Netduino - New boards in town!

Just in case you haven't already seen it, there is a number of new .NET MicroFramework 4.1 devices in town, 3 to be exact, - the "Netduino".

The company Secret Labs have made these nice boards of which 2 are Arduino hardware compatible (it can use many of the same "Arduino shields" (plugin interface boards) - some may need minor modifications to the signal levels!) and one is "Basic Stamp 2" compatible..

The Netduino comes in several flavours - all based on the same Atmel 32-bit ARM7 chip AT91SAM7X512 - Standard, Plus and Mini.

I have grabbed some product pictures from the Secret Labs homepage (left to right: Standard, Plus):


Netduino standard Netduino Plus


The Mini is only 0.6"x1.2" (~15mmx30mm) in size. It plugs directly into a breadboard, as the pins are spaced on a 0.1" standard grid:

Netduino Mini


As of the date of writing this, only the Netduino standard board is available for purchase, but the other 2 will also be available soon, according to Secret Labs.

Like the Arduino concept, the Netduino is also Open Source. This means that you can get hardware schematics, board design files and software and reuse it for your own purpose :-) 

Standard and Plus are Arduino pin compatible development boards, where the Mini is like a "24-pin DIP chip" you can use in your own hardware designs. The Mini is "Basic Stamp 2" pin compatible (from the company Parallax).

The Netduino Plus, has built-in ethernet connector.

I personally find the Netduino Mini to be the most exiting of them all.

I bought one of the "standard" editions. It is priced nicely at US$34.95.  My experience with it is that it just worked when plugged in to the PC. It has good performance and enough of memory too.

One thing I noticed which I especially like, is that the USB interface is fast and reliable, unlike some of the other boards from other vendors I also have experience with!

Technical specifications for the Netduinos can be found here:

Netduino Standard specifications
Netduino Plus specifications
Netduino Mini specifications


Thumbs up and welcome to the new inhabitants in the .NET MicroFramework world.


Adding a hardware button keypad to the AMI board

One of the things you notice when you receive the AMI board, is that there are no hardware buttons on the board.

This article shows you how to connect hardware buttons so you can get started testing all the sample WPF applications that use the navigation buttons and of course write your own programs.

Please note that AUG Elektronik already have a nice looking ready made solution as an add-on board for the AMI. This add-on board have a number of extra features and you can read about it here.

If you feel like making your own simple keypad, then keep reading.

AMI board

The AMI board from the Austrian company AUG Elektronik, is in my opinion more than just a prototyping/development board like you have seen from other vendors. The board is ready to be used and incorporated in your own products.  

When you develop software for this board, you will most definitely need a hardware keypad with a basic set of buttons, like the up/down/left/right/select buttons. But you have to add this yourself or buy the add-on board from AUG. It is however very easy to attach a set of buttons to the board, as all GPIO pins are available on a set of Micro-Match connectors on the back of the board.

Navigation buttons and connectors

What you need is 5 buttons of good quality, a piece of stripboard/vero board to mount the buttons on and some wire. When you receive the box with the AMI board you get  a set of Micro-Match male connectors that connects to the board. Use these to connect the buttons.

A schematic diagram of the wiring will look like this:


The AMI board microcontroller uses internal pull-up resistors for the input pins, so a diagram with the detailed connections are as this:

The codes shown as "P5.9", refers to the Micro-Match connector on the AMI board, where P5 is the name of the connector and the ".9" means "pin 9". So "P5.9" means "Connector P5, pin 9".  The references I have used are the same as you can find in the technical manual from AUG Elektronik.

Remember to connect the ground connection, which can be found on P4.2

Click on a picture to see it in a larger version.


Additional buttons

In my version of the keypad, I have mounted more than the 5 navigation buttons (although not yet wired). This is only because I found it easier to mount all buttons now when I had heat on my soldering iron and as there are more GPIOs to be used... As you can also see I have used buttons with built-in LEDs. It is always good to be prepared for the future!

Have fun 


I have lost connection to my Tahoe-II board!

Oh no. This is not true. After only a week I have lost the communication to my Tahoe-II board :-(

While I was doing some testing with a simple program toggling a few output ports, VS2008 suddenly reported that it could not see the device anymore. My testprogram was running along fine though. I have seen from time to time that VS does not deploy successfully in first attempt, but then I just try again, which normally succeeds.

This time I unplugged the USB cable and reconnected - Argh: Windows tells me that the USB device is not recognized. Reboot the PC didn't help. Reinstall the USB driver and the SDK didn't help. I moved the board to another PC (Windows XP), but that gives the same result.

Now I have filed the issue to Device Solutions and a newsgroup for help and just hope for the best.

My "Dare to Dream Different" future is at stake.


UPDATE Problem solved: Jan Kučera has saved my future. Newgroups are your friend.

Jan writes:
"Be careful of your debug mode setting. First try to switch to USB, which you can do be holding SW3 while pressing RESET. This is too how you could change it by accident (SW2 selects serial, SW4 selects Ethernet).

The current recovery firmware does not affect this setting, so it won't help you if this is the problem."

I pressed SW3 and RESET - Eureka I'm back in contact! - Thanks Jan.


Tetris for Tahoe-II board

Pavel Bánský made this great game and demo application for the Tahoe classic (Tahoe I) development board last year.

Since then a new version of the development board from Device Solutions has come out and they switched the screen from portrait to landscape mode. They also made some changes to how you reference the buttons on the board.

So in order to make the Tetris game run on the Tahoe-II, I have made some adaptations.

Here are a few pictures of it. It runs in the Tahoe-II emulator as well.

You can download the adapted code from here: MicroTetris3.zip (41.00 kb)

All credits to Pavel for a great program.


New Micro Framework development kit from AUG Elektronik Gmbh

AUG Elektronik Gmbh, from Austria is in the process of making a new Micro Framework based development board. According to the specifications, it looks like a real killer! Plenty of memory and an OLED Display in a nice high resolution.

Andreas Schloffer from AUG, informs me that the capacitive keypad mentioned in the specs. is a transparent keypad which makes it possible to place the display behind a glass surface to make sure that the system is vandal safe and still use the touch functionality. You do not use both the resistive keypad and the capacitive keypad at the same time.

You can find more info on the company homepage here: AUG Elektronik Gmbh

Some of the specifications (from the technical product sheet) are:

- Atmel AT91SAM9261 (200 MHz)
- 160 kB SRAM (internal)
- 256 MB NAND Flash
- 3.4” OLED Display 480x272, 24 BPP RGB
- resistive touch screen (SPI)
- capacitive sensor keypad (16 keys, I2C)
- 4 serial Ports (2 RS-232, 1 RS-485, 1 Debug RS-232)
- 10/100 MBit Ethernet Auto-MDI
- I2C Bus
- SPI Bus
- battery backed realtime-clock (I2C)
- several (15) free GPIOs (more depend on peripherals)

.NET Micro Framework 3.0
USB Host (Note 1)
USB Device (Note 1)
Micro SD-Card slot (Note 1)
single 5 V power supply
PowerOverEthernet PoE power supply (optional)

Note 1: Features are not yet implemented in MF core or in the AUG port!


Dare To Dream Different hardware arrived today

Yihaa, today I received a package with the MF development board and other stuff.

The package contains the Tahoo-II development board from Device Solutions, a USB cable, 2 XBee 802.15.4 radio modules from Maxstream and an XBee development board so that one of the radio modules can be connected to a PC on the USB port. 

There was no USB cable for the XBee development board and there is no documentation on the XBee stuff at all! I will probably also need a USB driver for that board. - Well I guess that I just have to find it on the Internet...

XBee dev. board to the left and Tahoo-II board to the right. Two XBee radio modules on the top.


The backside of the Tahoo-II board - the Meridian MF processor in the lower left corner.


The Meridian processor board is not much bigger than a standard SD memory card! 



Close up on the two XBee modules.  


The XBee development board. 


 This just looks nice and I'm looking forward to get started playing with it.