1.0 pinout: added SDA and SCL pins for TWI communication placed near to the AREF pin and two other new pins placed near to the RESET pin, the IOREF that allow the shields to adapt to the voltage provided from the board and the second one is a not connected pin, that is reserved for future purposes.ATmega16U2 instead 8U2 as USB-to-Serial converter.

The Uno differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip.Īdditional features coming with the R3 version are: It contains everything needed to support the microcontroller simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz ceramic resonator (CSTCE16M0V53-R0), a USB connection, a power jack, an ICSP header, and a reset button. This time the average consumption was 7.34 mA which was higher than the addition test.The Arduino Uno Rev3 SMD is a microcontroller board based on the ATmega328. I changed the multiplier to 41 which does not become zero. I'm still not sure I believe the results, perhaps someone else would like to try to reproduce them? UpdateĪs Edgar Bonet pointed out, the multiplication test became zero after 14 iterations and thus it gave the processor the simpler task of multiplying by zero. Still, as you can see from the generated code, most of the instructions are 'helper' instructions (like loading from registers, storing to registers, looping etc.). Setting all ports to output and low was intended to remove any side-effects from spurious inputs on the input ports. I found this rather surprising, that it used less power doing a multiplication compared to an addition. Generated code a6: 4a e2 ldi r20, 0x2A 42 Multiplication Test sketch volatile int foo = 100 However it was tested on an Atmega328P.Īddition Test sketch volatile int foo = 100 ĭDRB = 0b00111111 // all ports to output I didn't use a Uno because the power used by the 'power on' LED and the voltage regulator tend to swamp the power consumption of the chip itself. Having said that, I set up a couple of tests and measured the power consumption. For example, turning on the ADC unit (for analog reading), or by setting an output pin high or low. The only power consumption change would be if the instruction had a side-effect on a peripheral. The chip is always fetching and executing instructions, unless you have put it into one of its sleep modes. The power consumed by the chip won't change much by multiplying (compared to, say, adding).

Arduino uno atmega328 adiw datasheet