The main chip ATmega328P clocked at 8 MHz and at 3.3V logic, which use the Arduino pro mini 8Mhz 3.3V bootloader, usage same as the Arduino pro mini. This chip has 32K of flash and 2K of RAM. On board with a 3.7V 14500 battery holder, so it can use anywhere you like. In this LoRa Radio Node, we break out 2 IIC ports, 2 analog port (A0 A1) and 2 digital port (D3 D4) with 4 pin and 3 pin 2510-I type header. Feature: Power supply: 3.7V 14500 Lipo battery Or 3.7-12V DC power(VCC GND: 2PIN 2510-I Type connect) Size: 40mm x 60mm ATmega328P @ 8MHz with 3.3V logic/power 3.3V regulator with 500mA peak current output Hardware Serial, hardware I2C, hardware SPI support 1 x PWM pins: D3 2 x analog inputs: A0 A1 Pin #13 BLUE LED for general purpose blinking 2 mounting holes Reset button This LoRa Radio Node uses the extra space left over to add an RFM9x LoRa 433 MHz radio module. These radios are not good for transmitting audio or video, but they do work quite well for small data packet transmission when you need more range than 2.4 GHz (BT, BLE, WiFi, ZigBee). SX1278 LoRa® based module with SPI interface Packet radio with ready-to-go Arduino libraries Uses the amateur or license-free ISM band: ITU "Europe" license-free ISM or ITU "American" amateur (with amateur band limitations) +5 to +20 dBm up to 100 mW Power Output Capability (power output selectable in software) ~300uA during full sleep, ~120mA peak during +20dBm transmit, ~40mA during active radio listening. spot for uFL connector