Overview This is a handy, low power Raspberry Pi HAT which features multi communication functionalities: GSM, GPRS, and Bluetooth. It allows your Pi to easily send messages, connect to wireless Internet, transfer data via Bluetooth, and so on. Features Raspberry Pi connectivity, compatible with Raspberry Pi 2B/3B/3B+/Zero/Zero W Supports SMS, GPRS, DTMF, HTTP, FTP, MMS, email, etc. Bluetooth 3.0, supports data transferring through Bluetooth UART interface, for connecting host control boards like Arduino/STM32 Onboard voltage level translator, 3.3V by default, switch to 5V via jumper 2x LEDs for indicating the module working status SIM card slot for 1.8V /3V SIM card Baudrate auto detection (1200bps ~115200bps) Control via AT commands (3GPP TS 27.007, 27.005, and SIMCOM enhanced AT Commands) Supports SIM application toolkit: GSM 11.14 Release 99 Comes with development resources and manual (examples for Raspberry Pi/Arduino/STM32)