Buttons, LEDs and buzzer

  • 5 buttons
  • Green LED
  • Yellow LED
  • Buzzer enabled via jumper

With the Interface Nanoshield it's possible to add basic user interface elements to your project. It has 5 buttons, 2 LEDs (green and yellow) and one buzzer.

The buttons are connected to the Arduino A0 pin through a voltage divider, and can be checked via a simple analog reading. To know which button is being pressed, you just need to verify in which range of the table below the input voltage falls into.

The buzzer is connected to the D5# pin and can generate tones from 100Hz to 10kHz. If needed, you can disable it by removing the BZ_EN jumper on the board. The yellow LED is connected to the A1 pin and the green LED is connected to the A2 pin. To activate each LED, you just need to output a high logic level to the corresponding pin. The buzzer and the LEDs are activated through a transistor, reducing the load on the Arduino pin (see the schematics for details).

Interface Nanoshield Features

!Connection with Adruino and Base Board Uno

The easiest way to use the Interface Nanoshield along with an Arduino is by using the Base Board Uno or the Base Board L Uno. You just have to connect the boards and start writing code. This assembly can be used with an Arduino UNO, Mega R3, Duemilanove, among others (contact us in case you have doubts about compatibility with other versions). The picture below shows how the assembly looks like.

Connection with Arduino using the Base Board Uno (click on the image to zoom)

!Connection with the Base Boarduino

It is also possible to connect the Interface Nanoshield directly to our Arduino-compatible board, the Base Boarduino. The connection is done the same way as with the Base Board, as shown in the picture below.

Connection with the Base Boarduino (click on the image to zoom in)

!Direct connection with Arduino

The following schematics show how to connect the Interface Nanoshield directly to an Arduino UNO or Arduino Mega.

Connection using Arduino UNO (click on the image to zoom in)

Connection using Arduino Mega (click on the image to zoom in)


See on the table below which pin is related to each function of the Interface Nanoshield.

Interface Arduino Function
BUZ D5# Buzzer activation
BT A0 Buttons for analog reading
L1 A1 Yellow LED activation
L2 A2 Green LED activation
VCC VCC Power input - 5V
GND GND Reference voltage (ground)
Pinout table


Each button is related to an analog reading range of the A0 pin, as can be seen on the following table. By using the function analogRead(), for example, it is possible to check which button is being pressed, simply by using the values from the table below.

Button Analog Reading Range
Right less than 69
Up 69 to 230
Down 231 to 407
Left 408 to 630
SEL 631 to 896
No buttons pressed greater than 897
Button reading range

Buzzer response curve

The graph below shows the buzzer response curve, that is, the sound level produced by signals in various frequencies.


Buzzer sound level vs. frequency

Electrical specifications

  • Power supply: it’s done through the VCC pin, with a range from 4.5V to 5.5V (5V typical).

  • Current consumption: the average current consumption is 60mA with the buzzers and LEDs activated.

  • Logic levels: the buzzer and LEDs can be activated with logic levels of 5V or 3.3V. The output of the buttons' voltage divider has a maximum voltage of 5V and can be configured to operate with 3.3V through jumper VCCIO (see the schematics below for instructions).