[Product introduction] This is a strawberry pie expansion board with nb-IoT (Narrow Band Internet of Things) function. Domestic nb-IoT full Netcom, serial port AT command control, supports LWM2M/COAP/MQTT and other protocol communication. I have the advantages of low delay, low power consumption, wide coverage and low cost, and are very suitable for Internet of Things applications such as intelligent meters, asset tracking and remote monitoring. [Features of products] Based on Raspberry Pi 40PIN GPIO interface design, it is suitable for Raspberry Pi Series motherboards and Jetson Nano. Support LWM2M/COAP/MQTT/TCP/UDP/HTTP/HTTPS and other protocol communication Support domestic Onet/Telecom cloud/Ella cloud platform Onboard USB interface for power supply or software debugging The UART control interface is introduced and can be used to access the main control board such as Aurora/STM. The onboard level conversion circuit works at V by default and can be set to 5 V through jumper cap. Onboard simcard slot, nb-IoT dedicated card supporting China Telecom/Unicom/Mobile Onboard 2 LED indicators for easy viewing of module running status Support serial port baud rate range: 300bps ~ 921600bps (default 115200bps) Support AT command control (V.25TER, 3gpts 27.007 and simcom at command set) Provide a complete set of supporting data manuals (Raspberry/Aurora/STM 32/Python Sample programs and user manuals, etc) [Communication parameters of products] Support frequency band FDD-LTE B1/B3/B5/B8 Data transmission Upward: ≤ 62.5 Kbps Downward :≤26.15Kbps Short message Text and PDU mode (supported by nb card itself) Applicable area Asia (domestic nb-IoT Netcom) [Product parameters] Power supply voltage: 5 V Logic level: 5 V/3.3 V (default is 3.3 V) Flow consumption of the whole machine (Idle mode): about 18mA Single Module consumption (VBAT = 3.3 V ): Idle mode: 5.6mA Sleep Mode: 0.4mA PSM mode: 5uA EDRX mode current: 70uA (eDRX = 655.36 s) Product Size: 30.5mm x 65.0