TestBed for mbed


Communication Interfaces

10/100 Mbit Ethernet

Mbed allows the use of Ethernet within seconds IF an appropriate connector is attached. TestBed comes with a standard Ethernet Jack including the necessary mangetics (transformers and chokes) as well as two indicator LEDs to start a web connected application in no time.


TestBed supports the popular CAN Bus and is equipped with a connector following the CiA (CAN in Automation) standard. As transceiver IC a NXP PCA82C250 is used, allowing bus speeds up to 1MBaud.

RS485 Bus

Bus Connection is also possible via RS485, a differential bus quite similar to CAN, but without its harsh standards. A Texas Instruments SN65HVD3085 is the responsible transceiver, allowing TestBed to communicate at up to 1MBaud.


For quick and easy USB access, TestBed offers a mini USB connector. Over the USB connection, TestBed can optionally be supplied with power.

1x Standard UART

An UART interface is brought out on an angled 6-pin connector compatible with FTDI's USB-to-serial cables or small converter boards like FTDI Basic (Sparkfun) or USB2serial (Arduino/Smartprojects).

Expansion Sockets

Arduino Shields

Unleash the power of Arduino hardware by controlling expansion shields with mbed! The socket incorporates a simple voltage converter circuitry. This way, Arduino shields with analog outputs can be used even if they're based on 5V power domain.

Micro SD Cards

SPI-driven card slot for the popular SD standard (not SDHC!). Push-In/Push-Out style socket.

XBee Modules

Improve your mbed with wireless communication! Equipped with a socket for XBee-type wireless modules, TestBed enables mbed Software to "leave the hardware's boundaries".

Character LC Displays

Comes with 4-Bit Interface (Standard for most Text-LCDs), 4R7 resistor for LED backlight and a trim potentiometer for contrast setting. Mounting holes can be used to tighten the LCD on TestBed.

Built-In Features

Piezo Speaker

Small and easy to use signalling device. Driven by PWM, this speaker surely produces no high-end sound quality but has more than enough power for emitting accoustic warnings or acknowledges to user inputs etc.

RTC Backup Battery

Want keeping track of time even if your mbed hardware is unplugged from mains/battery power? TestBed feeds a steady voltage into the mbed's RTC using a long-life lithium battery. Great for Low-Power applications!

Analog Trim Poti

Nothing more than that - apply a voltage between 0 and 100% to the mbed's ADC.

Two Push Buttons

Allowing user inputs to control program flow.

Two LEDs

If four LEDs aren't enough - here are two more of them!


Application Examples

QVGA TFT Display with Touch Screen

We've prepared a tutorial for this. See here.

GDM2004D LC Display

This program demonstrates how to use the LCD included in the mbed Starterkit from Elektronikladen | Elmicro.

Import programTestBed-LCD20x4

Example of using a GDM2004D LCD with Elmicro\'s TestBed for mbed carrier board. Uses an altered version of the TextLCD-library.

Using RS485 communication

Following an example software for setting up the RS485 communication interface onboard the TestBed. Hopefully it helps you getting started with RS485.

Import programTestBed-RS485

Example software showing how to use TestBed\'s RS485 feature with mbed\'s hardware UART1. Currently only the setup routine and a \"SendText\" routine are implemented. Can easily be used to develop receiving messages and invoking IRQ handling.


TestBed for mbed is available as board-only version as well as bundled with an mbed1768 module, an LCD and several accessories (Starter Kit). It can be purchased through the Elektronikladen | Elmicro retail network.


12 comments on TestBed for mbed:

20 Nov 2011

If you want to use the sd card here is the needed port configuration: SDFileSystem sd(p11, p12, p13, p14, "sd"); MOSI,MISO,CLK,CS

29 Feb 2012

EMC Problem with TestBed does not allow Venus GPS to provide a fix/position


I would like to inform you about an EMC problem I have with the Testbed for mbed.

I was using the testbed in a configuration with an Xbee and the Venus GPS modul to transfer the NMEA messages to a remote Laptop.

The communication was running fine - I got the NMEA sentences but I never got a fix.

The Venus modul was positioned close to a window, so I thought the field of view to the satellites might be the root cause. A test outdoors provided same result.

Then I used another standalone reference GPS receiver close to the TestBed setup, but also this receiver did not provide a fix.

When I disconnected the power from the TestBed, I immediately got a position on the reference receiver.

At home I used the NXP LPC1768 on a breadboard with the Venus GPS and I got quite fast a position even at the window.

So my conclusion is that the Testbed is the origin of the radiation/noise falling into the GPS frequency range.

It would be interested to know, if this is observed by other users using the TestBed ,or if this is a unique problem with my TestBed.

Have fun and best regards


02 Mar 2012

Hi Michael,

thanks for this comment - we've never heard complaints about EMC problems from other customers yet. We've checked some TestBeds here in our workshop with u-blox 5 GPS receiver without problems. Perhaps you can contact our support so we can have a look at your TestBed? Did you power the TestBed via USB? Perhaps the USB cable attached to TestBed acted as an antenna? There aren't any "critical" components built upon our board which could cause high frequencies (besides the two LDOs which should be decoupled properly).

Again, thank you for your support!

Stefan from ELMICRO | Elektronikladen

04 Mar 2012

Hello Stefan,

thanks for your fast response.

I powered the TestBed with the power supply as part of the Starterkit. The USB cable was not used. The Venus GPS was connected via the UART of the TestBed and I used the 3.3V from the TestBed to power the Venus. These cables are about 20cm in length.

Thanks and best regards


20 Jun 2012

Is TestBed board still available? I do not find it in the web site.

20 Jun 2012

Hi Jesús,

the TestBed for mbed is available as stated above. Please have a look here:


It is sold through our reseller network - you can find your nearest Elektronikladen dealer here:


Feel free to contact us at leipzig@elmicro.com for further questions.

Regards, Stefan.

30 Sep 2012

Arduino shield pinout


15 Oct 2012

Hi Emil,

thanks for this nice overview! In fact, this should save quite some time figuring out the right signals when using Arduino hardware!

Best regards, Stefan.

31 Dec 2012

I am just new to mbed and LPC1768.

Is it possible to have sample code for ethernet communication using RJ-45 connector with magnetics on TestBed Kit.


02 Jan 2013

Hi Clive,

you can use whatever Ethernet Library you want. We already used the "original" mbed.org LwIP-Ethernet stack with good results as well as the Ethernet Stack from Donatien Garnier. For a start, just set up a project with the "Ethernet" class from the mbed.org libary!

If you have any further questions, feel free to contact us here or using our dedicated support E-Mail: support|AT|elmicro|DOT|com

Best regards, Stefan.

30 Aug 2013

It should be possible to get the Ethernet running with the Keil TCPNet Library as well, shouldn't it ? For some reason it seems the controller is out of service on my board, although the same code is working fine on MCB1700 with LPC1768. I want to migrate to Chip1768 on your testbed and continue using the Keil IDE and libraries due to existing projects.

09 Nov 2013

bonjour, no data transfer via testbed's miniUSB : Why ?. Power supply OK with JP8.

Merci for help

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