# GSM 2G gateway
# Compatible parts
| Module | Purpose | Where to Buy |
|---|---|---|
| A6 | GSM GPRS module | compatible parts list (opens new window) |
| A7 | GSM GPRS module with GPS | compatible parts list (opens new window) |
# Hardware setup
| Module Pin | NodeMCU / ESP8266 Pin |
|---|---|
| H_RXD | D6 |
| H_TXD | D7 |
| GND | GND |
| VCC5 | MOSFET driven by D5 |
For VCC5 you can power it directly all the time with an USB cable or use a MOSFET like here (opens new window)
Don't use the nodemcu/wemos 5V pin for the A6/7 power, use a dedicated power supply for both or dedicated to the A6/7 with at least 2 amps ability.
So as to start your A6/7 module press the red button for 4 seconds, or link the PWR_KEY GPIO to VCC5.0 for the same time.
