Smallest Sim800L GPRS GSM Module Microsim Card Core Board Quad-band TTL Serial Port with PCB Antenna [Original and New]

Description

The pinout (bottom side – left):

• RING (not marked on PBC, first from top, square) – LOW state while receiving a call
• DTR – sleep mode. Default in HIGH state (module in sleep mode, serial communication disabled). After setting it in LOW the module will wake up.
• MICP, MICN – microphone (P + / N -)
• SPKP, SPKN – speaker (P + / N -)

Pinout (bottom side – right):

• NET – antenna
• VCC – supply voltage
• RESET – reset
• RXD – serial communication
• TXD – serial communication
• GND – ground