The onboard two set power supply interface VCC5 +5V power supply, VCC4 interface, 3.5–4.5V power supply, optional power on self starting (default) and control start.
The onboard SMA (default) and IPX mini antenna interface, SIM900A interface reserved reset.
Standby dozens of MA data can be set to provide dormancy, dormancy of 10MA low power.
The serial port circuit: support for 3.3V single chip microcomputer.
NodeMCU is a IoT Module based on ESP8266 wifi Module. NodeMCU uses Lua Scripting language and is an open source Internet of Things (IoT) platform. This modules has CH340g USB to TTL IC
This is the XBee XBP24-BZ7UIT-004 module from Digi. Series 2 improves on the power output and data protocol. Series 2 modules allow you to create complex mesh networks based on the XBee ZB ZigBee mesh firmware. These modules allow a very reliable and simple communication between microcontrollers, computers, systems, really anything with a serial port! Point to point and multi-point networks are supported.