# GSM 2G gateway ## Compatible parts |Module|Purpose| |-|-| |A6|GSM GPRS module| |A7|GSM GPRS module with GPS| ## 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](https://gitlab.com/stavros/A6-ESP8266-breakout/raw/master/images/schematic.png) 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. ![Addon_2G](../img/OpenMQTTgateway_ESP8266_Addon_2G.png)