Description
Product details of Leonardo Pro Micro 16MHz 5V Replace ATmega328 Arduino Pro Mini
🛠️ Key Technical Details for a Pro Micro Clone
The Pro Micro uses the ATmega32U4 microcontroller, which is notable for its built-in USB communication.1 The 5V/16MHz version is the most common and operates with the following specifications:
-
Microcontroller: ATmega32U42
-
Operating Voltage (VCC): 5V
-
Clock Speed: 16 MHz3
-
Flash Memory: 32 KB (4 KB used by the bootloader)
-
SRAM: 2.5 KB
-
EEPROM: 1 KB
-
Digital I/O Pins: 18 (some shared with analog/PWM)4
-
Analog Input Pins (ADC): 9 (A0-A3, A6-A10)5
-
PWM Channels: 5 (or more, depending on which pins are used)6
-
USB: Built-in USB 2.0 (Micro USB connector is typical)
-
Power Input (RAW): Unregulated, typically 6V–12V (up to 16V absolute max, but 12V is safer for the voltage regulator).7
Required Components for a Minimal Board
To design a functional clone, you would need at least:
-
ATmega32U4 Microcontroller (typically in a QFN or TQFP package).8
-
16 MHz Crystal Oscillator and associated load capacitors (e.g., 9$2 \times 22 \text{pF}$ to 10$2 \times 33 \text{pF}$).11
-
Power Regulation: A 5V low-dropout (LDO) linear voltage regulator (e.g., NCP1117-5V) for the RAW input.
-
Decoupling Capacitors: Multiple small ceramic capacitors (e.g., $100 \text{nF}$) placed close to the VCC/GND pins of the ATmega32U4.
-
USB Micro-B Connector and associated data line protection (e.g., ESD diodes/filter).
-
Reset Circuit: A pull-up resistor on the 12$\text{RESET}$ pin and an optional reset button.13
-
Pin Headers: Two rows of through-hole pads for connecting to the standard 0.1-inch header spacing, matching the Pro Micro pinout.
📌 Pinout and Functionality
The Pro Micro’s pin mapping is crucial for software compatibility. It’s similar to the Arduino Leonardo, as both use the ATmega32U4.14 The 2-row pin header breaks out various pins:
| Pin Type | Function/Label |
| Power | $\text{RAW}$ (Unregulated Input), $\text{VCC}$ (Regulated 5V), $\text{GND}$ (Ground) |
| Digital | $\text{D0 (RX)}$, $\text{D1 (TX)}$, $\text{D2 (SDA)}$, $\text{D3 (SCL)}$, $\text{D4}$, $\text{D5}$, $\text{D6}$, $\text{D7}$, $\text{D8}$, $\text{D9}$, $\text{D10}$, $\text{D14-D16}$ |
| Analog | $\text{A0-A3}$ (also Digital $\text{D18-D21}$), $\text{A4-A5}$ (Shared with $\text{D4, D5}$ on some boards), $\text{A6-A10}$ (Analog only on other pins) |
| Communication | $\text{RX/TX}$ (Hardware Serial 1), $\text{SDA/SCL}$ ($\text{I2C}$), $\text{MOSI/MISO/SCK}$ ($\text{SPI}$) |
| Control |
$\text{RST}$ (Reset) |
The onboard USB capabilities allow it to be programmed and communicate directly, bypassing the need for a separate $\text{USB}$-to-$\text{Serial}$ chip like the ATmega16U2 found on the Uno R3.
You can find the official schematic and design files for the SparkFun Pro Micro, a popular reference design, which will guide you in component placement and routing if you choose to design a custom PCB.15 This video explains the pin functions and power options on the Pro Micro board
Reviews
There are no reviews yet.