5 V sensors, shields and legacy peripherals
5.0 V I/O drives 5 V logic directly — no level shifting.
Engineering inference
Arduino S.r.l
Arduino UNO R3
Classic 5 V Arduino: ATmega328P (DIP) at 16 MHz, 32 KB flash, 2 KB SRAM, 1 KB EEPROM, 14 digital I/O (6 PWM), 6 analog inputs, USB-B via ATmega16U2, 2.1 mm DC jack 6–20 V.
A000066Development boardPrice$27.60Arduino Store (USA) · in stock
Buy at Arduino Store (USA) Board essentials
Facts about the complete product. Unknown values remain open design questions.
- Exposed GPIO
- 20
- Board I/O voltage
- 5 V
- Board flash capacity
- 32 KiB
- Board SRAM capacity
- 2 KiB
- Board operating range
- -40 to 85 °C
A good fit for
Guidance to help you shortlist. The basis is shown for each recommendation.
Arduino shield ecosystem
Arduino Uno-compatible headers accept existing shields.
Engineering inferenceLearning and fast prototyping
Programs from Arduino IDE, Arduino Cloud Editor.
Engineering inferenceInside this board
The board is the parent product. Each chip has its own memory, pins, capabilities and thermal limits.
main processor
ATmega328P
Microchip Technology
9ffd306b-30c4-5779-a73e-e39cae662f52--mcu- Architecture
- 8-bit AVR RISC
- Documented clock
- 20 MHz
- Chip / in-package flash
- 32 KiB
- On-chip SRAM
- 2 KiB
usb uart bridge
ATmega16U2
Microchip Technology
9ffd306b-30c4-5779-a73e-e39cae662f52--usbvoltage regulator
SPX1117M3-L-5
MaxLinear
9ffd306b-30c4-5779-a73e-e39cae662f52--regop amp
LMV358LIST-A.9
STMicroelectronics
9ffd306b-30c4-5779-a73e-e39cae662f52--opampresonator
ECS-160-20-4X-DU
ECS
9ffd306b-30c4-5779-a73e-e39cae662f52--oscFAQ
Arduino UNO R3 questions
What microcontroller does the Arduino UNO R3 use?
The Arduino UNO R3 is built around the ATmega328P, alongside ATmega16U2, SPX1117M3-L-5, LMV358LIST-A.9, ECS-160-20-4X-DU.
How many GPIO pins does the Arduino UNO R3 have?
20 GPIO pins are exposed. Xirkit documents 32 board pins, 23 of them with pin-level electrical limits.
Are the Arduino UNO R3 I/O pins 5 V tolerant?
Yes, the documented I/O pins are 5 V tolerant. Input-high threshold: 3–5.5 V.
How much current can a Arduino UNO R3 GPIO pin source?
Documented output-high current per pin: ≤ 40 mA. Values are traced to the chip datasheet; see the pinout table for per-pin limits and conditions.
What voltage powers the Arduino UNO R3?
Supply range 1–20 V. Power inputs: VIN (6–20 V), AREF (1–5 V).
How much does the Arduino UNO R3 cost?
From $27.6 at Arduino Store (USA). Prices are observed unit prices before tax and shipping.
What are the Arduino UNO R3 dimensions?
68.58 × 53.34 mm. A STEP model is available for enclosure fit checks.
Which interfaces does the Arduino UNO R3 support?
gpio, control, interrupt, adc, i2c, uart, pwm, timer, analog_comparator, clock, spi, led, usb.
How do I program the Arduino UNO R3?
Supported frameworks: Arduino IDE, Arduino Cloud Editor.
Where does this Arduino UNO R3 data come from?
Every value in this record is traced to a source — 2 documents including the board and chip datasheets — with the page and table cited per value. Unknowns are left explicit, never guessed.
Data & sources
Where these values come from
- Arduino UNO R3 datasheet — Arduino S.r.l
- Arduino Store (USA) listing