How to Choose Arduino-Compatible Boards for Your Project
Choose an Arduino-compatible board by pins, size, and radio. The UNO R3 gives 14 digital pins, while the Nano gives the same chip in a small case. The UNO costs from $9.27, and the Nano costs $10.96. The BluePill gives a 72MHz ARM chip for $11.48.
Quick facts
| Fact | Value |
|---|---|
| UNO R3 | From $9.27, ATmega328P, 16MHz, 14 digital pins |
| Nano 3.0 | $10.96, ATmega328PB, CH340C, Type-C |
| BluePill Plus | $11.48, Cortex-M3, 72MHz, 64KB flash |
| BluePill CBT6 | $13.08, Cortex-M3, 72MHz, 128KB flash |
| S2 Mini | $11.16, 4MB flash, 2MB PSRAM, WiFi |
| RP2040 Pro Micro | $8.37, 16MB flash, dual-core RP2040 |
| TCRT5000 sensor | $7.02, 4-pack, 1 to 25mm range |
Which board fits a first Arduino project?
The UNO R3 gives 14 digital I/O pins and 6 analog inputs. It carries an ATmega328P chip at 16MHz with a CH340G USB-serial chip.
It costs from $9.27, with USB-B or Type-C versions. With a cable included, prices run $10.38 to $10.64.
Arduino documents the Uno Rev3 layout and pin map. The compatible board follows that same layout.
When should you pick the Nano?
The Nano 3.0 gives the same Arduino workflow in a small case. It carries an ATmega328PB chip with a CH340C USB-serial chip.
It uses Type-C USB and costs $10.96. That suits breadboard builds where a full UNO will not fit.
Pick the Nano for robots and drones where size matters. Pick the UNO for bench lessons where pins must stay visible.
When should you pick the BluePill STM32?
The BluePill Plus carries an ARM Cortex-M3 chip at 72MHz. That is faster than the 16MHz ATmega328P on the UNO.
It gives USB-C and SWD debug on the board. The C8T6 version gives 64KB of flash for $11.48.
The CBT6 version gives 128KB of flash for $13.08. Pick it when your sketch outgrows 64KB.
When should you pick a WiFi board instead?
Pick the S2 Mini at $11.16 when the project needs WiFi. It gives 4MB of flash and 2MB of PSRAM over USB-C.
Pick the SuperMini C3 at $10.99 for a tiny WiFi build. It gives WiFi and Bluetooth in C3, C6, S3, and H2 versions.
The UNO and Nano give no WiFi radio. Use them for wired sensor and motor jobs.
What sensors work with these boards?
The TCRT5000 line sensor reads 1 to 25mm with a digital output. It costs $7.02 for a 4-pack and takes 3.3V to 5V.
The TFT LCD display gives an IPS SPI screen in 0.96 to 2.8 inch sizes. Prices run from $5.83 to $10.92 by size.
Both parts work with Arduino and ESP32 boards. That lets you reuse sensors when you swap boards.
How the options compare
| Board | Chip | Key spec | Price |
|---|---|---|---|
| UNO R3, Type-C | ATmega328P | 16MHz, 14 digital pins | $9.27 |
| Nano 3.0 | ATmega328PB | Type-C, small case | $10.96 |
| BluePill C8T6 | STM32F103C8T6 | 72MHz, 64KB flash, USB-C | $11.48 |
| BluePill CBT6 | STM32F103CBT6 | 72MHz, 128KB flash, USB-C | $13.08 |
| S2 Mini | ESP32-S2FN4R2 | 4MB flash, 2MB PSRAM, WiFi | $11.16 |
| RP2040 Pro Micro | RP2040 | Dual-core, 16MB flash, USB-C | $8.37 |
| TCRT5000, 4-pack | Sensor module | 1 to 25mm, digital output | $7.02 |
How do you choose an Arduino-compatible board in five steps?
- Write down the job: first project, small build, or fast code.
- Pick the UNO R3 for a first project with visible pins.
- Pick the Nano when the build must fit a breadboard.
- Pick the BluePill when your sketch needs 72MHz speed.
- Pick the S2 Mini when the project needs WiFi.
Parts that fit this guide
In-stock parts ship from the New York, USA warehouse in 1-2 business days. Prices below are the live store prices we verified on November 10, 2026.
UNO R3 Compatible Development Board, ATmega328P CH340G – USB / Type-C ($9.27)
UNO R3 compatible board at $9.27 to $10.64 by version. It carries an ATmega328P chip, runs at 16MHz, and gives 14 digital pins and 6 analog inputs.
Arduino Nano 3.0 Compatible Development Board, Type-C USB, ATmega328PB, CH340C ($10.96)
Arduino Nano 3.0 board at $10.96. It carries an ATmega328PB chip with a CH340C USB-serial chip and Type-C USB.
BluePill Plus STM32F103C8T6 / STM32F103CBT6 ARM Cortex-M3 Development Board, USB-C ($11.48)
BluePill Plus board at $11.48 for 64KB flash. It carries an ARM Cortex-M3 chip at 72MHz with USB-C and SWD debug.
ESP32-S2 Mini Development Board, WiFi, 4MB Flash, 2MB PSRAM, USB-C ($11.16)
ESP32-S2 Mini at $11.16 for a 1-pack. It gives 4MB of flash and 2MB of PSRAM with WiFi over USB-C.
RP2040 Pro Micro Development Board, 16MB Flash, USB-C, QMK Compatible ($8.37)
RP2040 Pro Micro at $8.37. It gives a dual-core RP2040 chip with 16MB of flash, USB-C, and BOOT and RESET buttons.
TCRT5000 Infrared Reflective Line Tracking Sensor Module, 4-Pack ($7.02)
TCRT5000 sensor at $7.02 for a 4-pack. It reads 1 to 25mm with a digital output on 3.3V to 5V.
TFT LCD Display Module, IPS SPI, 0.96-2.8 inch, ST7735/ST7789/ILI9341 ($5.83)
TFT LCD display at $5.83 to $10.92 by size. It gives an IPS SPI display in 0.96 to 2.8 inch sizes with 65K colors.
Shop the full range: Arduino-Compatible Boards at Quality RC Parts. See also: Related guide.
Frequently asked questions
What is the cheapest board here?
The TCRT5000 sensor 4-pack at $7.02. The cheapest board is the RP2040 Pro Micro at $8.37.
UNO or Nano: which should I pick?
Pick the UNO for bench lessons and the Nano for small builds. The UNO costs from $9.27, and the Nano costs $10.96.
How much flash does the BluePill give?
The C8T6 gives 64KB for $11.48, and the CBT6 gives 128KB for $13.08.
Does the UNO have WiFi?
No. The UNO gives an ATmega328P chip at 16MHz with no WiFi radio. Pick the S2 Mini for WiFi.
Sources
Last updated: November 10, 2026.