New Product in stock: OLIMEXINO-NANO wearable Arduino Leonardo clone


In October I blogged for our new Arduino clone: The NANO with size only 30x30x8 mm.

Well we have them all three in stock now!

OLIMEXINO-NANO is the core module with USB micro connector, the stackable connectors for shields and UEXT to connect our many UEXT modules like BMP085, MPU6050, HMC5883L, Zigbee, temperature, magnetometers etc. etc.

OLIMEXINO-BB is stackable shield which allow you to connect NANO to Breadboard-1

OLIMEXINO-BAT is shield which contain Lithium 3V battery, connector for LiPo battery and on board charger.

The power supply for NANO is made very intelligently and as soon you connect LiPo it will take power from there, if the USB is connected the batteries are disconnected and start charging them.

We have two more modules which will be ready in few weeks:

  • EUR 10 Bluetooth 4.0 BLE shield which will allow the wearable NANO to be connected to iPhones without licensee issues or to Android phones with Bluetooth 4.0 and will allow interactions with phones and tablets with different sensors connected to NANO
  • EUR 22 GSM/GPRS 4 band shield with external antenna which will add connectivity via GSM

The NANO shield concept is that the connectors are SMT type and stackable, on bottom there is male connector, on top is female connector so you can stack as many shield as you want together.

Look Mom! I shrink the Arduino!


We love to play with Arduino and like it very much but one thing have always bothered us – it’s HUGE.

What you do when you want to make small data logger, RF/Zigbee baecon, sensor network, something wearable etc? use this BRICK? No way.

This is how the idea for OLIMEXINO-NANO came.

We made complete Arduino replacement with size of only 30x30x8 mm


What you see on the pictures above is TOP and BOTTOM view of the OLIMEXINO-NANO.

It have these features:

  • ATMega32U4 processor (Leonardo compatible)
  • micro USB connector for programming and power supply when debugging
  • RESET button
  • USER button
  • microSD card connector for data logging on SD-card
  • UEXT connector for RF, Zigbee, Ethernet, RELAY, RGB LED, etc UEXT modules
  • two status LEDs
  • Connector 14 pin 0.05″
  • Connector 20 pin 0.05″

the connectors allow other boards to stackup like normal Arduino shields.

The first shield we made is with Battery power supply:



On this battery shield there is:

  • power ON/OFF switch
  • LiPo battery connector for our 1400mA/2200mA/3000mA/4400mA/6600mA batteries
  • LiPo charger with three status LEDs
  • Li 3V CR3023 battery holder

Here are how NANO and BATTERY shield snap together:



both fit perfectly in this small plastic enclosure:


The next shield was to allow easy connection to Breadboard:




Here is view of BreadBoard shield with Battery shield snap on top:


And here is same with NANO snap on bottom:


and here is side view:


Here is again how NANO looks next to OLIMEXINO-328 (Arduino-2009 clone)


and to cigarette lighter:


and together with the small 45 x 40 x 20 mm enclosure:Image

As you see above these three boards are the first prototypes which we built, now we will do some testing and run production in November. The prices? They will be very competitive and similar to OLIMEXINO-32U4 which uses same processor.

Another shield we work now on is Bluetooth 4.0 BLE shield which to snap and to allow trouble free connection to iPhone and Android devices

WII NUNCHUCK projects with Arduino Leonardo AVR-T32U4


WII NUNCHUCK is low cost joystick and 3 axes accelerometer combo which could be read by I2C.

We created UEXT plug-in board which allow WII-NUNCHUCK to be used with any of our development boards with UEXT connector.

Here on this video:

you can see four projects made with WII-NUNCHUCK

1. Mouse – you can move the mouse pointer with Joystick and to use the two buttons as mouse buttons

2. Sound – with the 3 axes accelerometer you can change the pitch of the generated tone

3. Driving two servos with the 3-axes accelerometer

4. Drivinig RGB stripe with MOD-RGB and MOD-WII-NUNCHUCK – as AVR-T32U4 have just one UEXT port we use the UEXTx5 extender.

The demo code is at GitHub:

AVR-T32U4 Arduino Leonardo interfacing to LEDs and Buttons in LED game


We create small video tutorial how to connect LEDs and Buttons to AVR-T32U4 Arduino Leonardo and create small Game.

The code is on GitHub

AVR-T32U4 Arduino Leonardo experiments with knock sensor and servo


This is simple fun project which we build for couple of minutes with materials in the office.

What you need: AVR-T32U4 Arduino Leonardo clone, Breadboard-1 for AVR-T32U4, LiPo battery, some JumperWires, Knock sensor, MS-1.3-9 servo motor, some tape and empty carton box.

Tape the servo in the corner and put on it plastic arm which to rise the box lid, tape the knock sensor to the lid. Connect the servo to D9 and Knock sensor to A0 of AVR-32U4.

The code Knock.ino is on GitHub, as you can see it’s pretty simple, once on A0 is detected level above some threshold (you can experiment what this level is in your case as it depend on how you attach the knock sensor to the box) you move the servo motor up wait some time and move it back.

Watch the video in action:

Then one of our practicing students at Olimex decided to make code which will open the box only if you knock in some secret sequence of long and short knocks and the code is also on Github (please be gentle the code is crappy but written by enthusiast with no much experience).

The new video for the password knock is here:

Measuring temperatures from -250C to +1600C with AVR-T32U4 Arduino Leonardo and MOD-TC-MK2-31885 + thermocouple


MOD-TC-MK2-31885 is UEXT module which uses MAX31885 and allow temperatures in range -250C to +1600C to be measured with proper thermocouple.

For this demo we use TC-K-TYPE which is low cost K-type thermocouple.

When the thermocouple is connected pay attention that it have polarity i.e. if your measurements start to decrease when you increase the thermocouple end temperature you have to swap the thermocouple wires to the connector.

Another issue we got with Arduino 1.0.4 is that Serial print from time to time stop working on Leonardo and several uploads usually solve the problem, we guess this is some USB port problem and Leonardo is not properly enumerated as CDC serial port every time.

Also I2C library on Leonardo sometimes beahve weird and in this case you have to decrease I2C speed a bit. So if the sketch do not work correctly just edit TWI_FREQ to 80000L in:


#ifndef TWI_FREQ
 #define TWI_FREQ 100000L

You can watch the demo at this video:

As you can see there are two temperatures which are measured: the temperature on the thermocouple TC and the internal MAX31855 temperature INT (i.e. cold end thermocouple temperature).

Also MAX31885 recognize if the thermocouple is disconnected, shorted or connected to VCC.

The demo code is at GitHub:

AVR-T32U4 Arduino Leonardo Analog Servo motor drive demo


We stock now 6 types of Analog Servo drive motors

The motor parameters are encoded in their names:

MS-1.3-9 means – Servo-Motor with 1.3 force and 9 gram weight.
MS-R-1.3-9 means Servo-Motor with 360 degree angle and 1.3 force and 9 gram weight.

All servo motors came with various exchangable plastic arms:


Separately are available aluminum ARMs which can snap to the bigger 3.2 and 6 motors, these are so powerful than can open and close drawers.

Adruino have special library for servo drive just notice that the normal servos will accept angle between 0 and 120 degree only, while the R type will accept from 0 to 360 degree.

The demo code is on GitHub:

You can see the code running on this video

Arduino Breadboarding with AVR-T32U4


AVR-T32U4 is the easiest way to do breadboard projects with Arduino. With retail price of EUR 12.95 this is also the Arduino board with best price/performance ratio.

As you see from the picture above AVR-T32U4 snap perfectly to Breadboard-1 and it powers the two power buses with 3.3V and GND and you have access to all Arduino pins A0-A5 and D0-D13 on the breadboard area, so you can easily connect to LEDs, Servo Motors,  Sensors etc.

Here is step by step instructions what you have to do to get started.

1. Download Arduino IDE from; Unpack the downloaded zip file in main drive C:\arduino-1.0.4

2. Plug AVR-T32U4 to your PC and it will ask for drivers, point it to C:\arduino-1.0.4\drivers

3. After the drivers are installed run C:\arduino-1.0.4\arduino.exe

4. Select the board to be Arduino-Leonardo as per attached picture


5. Right mouse click on “My computer” then select Properties-> Hardware-> Device Manager and check which virtual COM port is created when you plug AVR-T32U4.


as you see on the picture in this case COM33 is created by Arduino-Leonardo

6. From Arduino menu select the com port as per attached picture:


6. Open Blink LED project:


7. Upload the sketch by click on -> button

Connect LED with longer led to D13 and shorter leg via 220 ohm to GND.

You should see the LED blinking as on this video:

Congratulations you just complete your first Arduino project!

We also highly recommend you when you do prototype work to put USB-ISO between your Arduino and PC in this case even if you do some stupid like to make short on your Arduino board or put wrong voltage somewhere your PC will be always protected, so even if your Arduino board burn your computer will be safe.



This is Open Hardware Arduino Leonardo compatible board.
What we did here are few features which are missing and we think they are annoying in original Arduino hardware design:
– made shield step to be aligned to 0.1″ so you can use this board in breadboards’
– add Lipo battery power supply for handhels operation
– moved the LEDs on close to the edge to be visible even with shield on it
– can work on both 3.3 and 5V
– add UEXT connector so you can use our UEXT modules like WIFi , Bluetooth, Zigbee, GSM, GPS, Thermocouples, Relays etc.

Everyone have chance to win this board if answer correctly our Quiz question.
Today at 17.00 o’clock our local Bulgarian time (GMT+3) we will post on Twitter our question.
You have one hour to reply to our tweet with the correct answer.
At 18.00 o’clock we will count the correct answers and ask to generate random number in range then anounce the winner and ship the board by airmail next Monday.

Good luck!



Arduino praxis made review of OLIMEXINO-32U4

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