Arduino ZERO – when ZERO is greater than ONE


Along with the new and highly anticipated Arduino TRE board, which in the meantime has been released in a limited edition (I have not purchased it given the high price at which it was proposed, that is over 150 EURs …:( ), the release of a new Arduino board was recently announced: the new Arduino ZERO.


Arduino Zero

This board will soon be added to the already wide family of Arduino team, taking the place currently occupied by Arduino UNO.

Indeed Arduino ZERO has the same size and same pinout of the now classic Arduino UNO, though by providing, thanks to the new embedded processor, large improvements in performance (both speed and memory).

Thus all lovers loyal to the now “old” Arduino UNO, can continue to use projects already developed, using the same code and shields; however, taking advantage of the increased performance that this new board offers.

The Arduino ZERO board

The Arduino ZERO board is a simple and powerful 32-bit extension of the Arduino UNO board. In fact, the pinout and all the features have been preserved in order to give continuity to this successful series that has seen the conclusion of the class UNO with its third revision.

In this new series, the ATmega328 of the Arduino UNO processor is replaced by a processor MCU (microcontroller unit) Atmel SAMD21  Atmel, with a 32-bit core ARM ® Cortex M0+ . With this replacement, the performance has considerably increased.

In addition to the processor, one of the most important features introduced in this board is an embedded debugger called EDBG. This debugger allows you to interface directly with the Atmel processor for both programming and debugging (here is the official guide) without any need of additional hardware.


Fig.1: the embedded chip EDBG

The EDBG chip is composed by three parts:

  • the debugger 
  • a virtual COM port 
  • a Data Gateway Interface (DGI)

The virtual COM port is connected to a UART port from the processor and provides a simple way to communicate with an “target” device through a simple terminal. Instead the Data Gateway interface consists of several physical data interfaces used for the connection with the host computer to which the Arduino board is connected.

Below a table shows the technical specifications of both Arduino boards to better compare the performance/features provided by each of them.

Microcontroller ATSAMD21G18, 48pins LQFP ATmega328
Operating Voltage 3.3V 5V
Digital I/O Pins 14, with 12 PWM and UART 14 (of which 6 provide PWM output)
Analog Input Pins 6, 12-bit ADC channels 6
Analog Output Pins 1, 10-bit DAC
DC Current per I/O Pin 7 mA 40 mA
Flash Memory 256 KB 32 KB (ATmega328) of which 0.5 KB used by bootloader
SRAM 32 KB 2 KB (ATmega328)
EEPROM up to 16KB by emulation 1 KB (ATmega328)
Clock Speed 48 MHz 16 MHz

Analyzing the technical characteristics of the two boards, you may well see an increase in of the potentialities of Arduino ZERO board with an operating speed that is four times the Arduino UNO speed. Also with regard to the memory, you can see that both the Flash Memory and SRAM have values ​​significantly higher.

In addition, observing the two cards in perspective (see Figure 2 and 3), we can see that the old port USB type A on the left edge, has been replaced with two USB micro-B type. A port keeps the classic functions that had the previous USB port, while the second is intended to interface directly with the Debugger (the USB port at the bottom).


Fig.2: Arduino ZERO


Fig.3: Arduino UNO Rev.3

And just to be thorough I’ll also show you the rear of the board


Fig.4: the Arduino ZERO rear


This board is destined to replace our Arduino UNO which until now we have jealously guarded inside our homes. Unfortunately nor information on the date of the release nor on their price (hopefully lower …) still have not been released.



  1. Mike Barela (from Google+)

    You say “This board is destined to replace our Arduino UNO which until now we have jealously guarded inside our homes. Unfortunately nor information on the date of the release nor on their price (hopefully lower …) still have not been released.” – will the Uno now be priced at 10 euro now and Zero at 30 euro?  or will Uno remain at 25 Euro and Zero be 50 euro?

  2. Daniel Osborne (from Google+)

    The great thing about the Uno is the replaceable chips. You can use the board as a cheap chip programmer for building arduino based circuits.
    Can’t do that with the Zero.

  3. Eric Valosin (from Google+)

    I wonder about the 3.3v and 7mA/IO pin limitations (as opposed to UNOs 5V and 40mA)

    • I worried about the 7mA as current limitation too. Regarding the 3.3v it is only the internal voltage of the board. In fact, there is a 5V pin as in Arduino UNO.

    • Daniel Osborne (from Google+)

      It said it was shield compatible with the Uno, so it doesn’t sound like it’s 3.3V.
      Personally, I prefer 5V. It may use more power, but compatibility is more important to me than power savings.
      Sure, those pins aren’t really designed to power much, but 7mA is pretty restrictive, IMO. That can’t even power an LED.

      EDIT: I just reread it. It does say 3.3V. I wonder how it’s compatible then? I won’t be getting it then. I don’t want 3.3V stuff.

  4. Justin Mitchell (from Google+)

    Afaics it will be pin compatible with uno shields, but at 3.3v.  Later revision arduinos, like uno r3,  includes an io voltage reference pin, with the intent that shields can detect which voltage the controller runs at and adapt, no idea if anyone actually makes such shields yet. and i agree that 7mA is pretty poor.

  5. Mike Barela (from Google+)

    Where does the DAC pin come out?  It does not look like that’s the unlabeled pin near the power section but could be

  6. Brett Cooper (from Google+)

    Nice but for that price you could get a few Raspberry Pis or a few BeagleBone Black or an Intel Galileo

  7. Mike Barela (from Google+)

    Price and he fact that there are about 5 different boards on the planet that work on 3.3 volts

  8. Joshua Bardwell (from Google+)

    Integrated debugger is really exciting, but I don’t see how it can claim to be shield-compatible with the Uno if the output pins are at 3v3 and they only support 7 mA.

  9. PaulStoffregen (from Google+)

    When/if you review Arduino Zero, I hope you’ll consider comparing it to Teensy 3.1 (available now, under $20) which is based on an ARM Cortex-M4 chip.

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