println( "AT+CSQ") //Signal quality test, value range is 0-31, 31 is the best updateSerial()
println( "AT") //Once the handshake test is successful, it will back to OK updateSerial()
Begin serial communication with Arduino and SIM800L Begin serial communication with Arduino and Arduino IDE (Serial Monitor) SoftwareSerial mySerial( 3, 2) //SIM800L Tx & Rx is connected to Arduino #3 & #2 void setup()
#include //Create software serial object to communicate with SIM800L The one uses 1200mAh Li-Po battery and other one uses LM2596 DC-DC buck converter. As you have multiple choices for powering up the module, we have provided two example schematics. Now we are remaining with the pins that are used to supply power for the module. A 10K resistor between SIM800L Rx and Arduino D2, and 20K between SIM800L Rx and GND would work fine. There are several ways to do this but the easiest way is to use a simple resistor divider. This means the Tx signal coming from the Arduino Uno must be stepped down to 3.3V so as not to damage the SIM800L module. We cannot directly connect Rx pin on module to Arduino’s digital pin as Arduino Uno uses 5V GPIO whereas the SIM800L module uses 3.3V level logic and is NOT 5V tolerant. Now, connect Tx pin on module to digital pin#3 on Arduino as we’ll be using software serial to talk to the module. Start by soldering/connecting the antenna, insert fully activated Micro SIM card in the socket. Now that we know everything about the module, we can begin hooking it up to our Arduino! Wiring – Connecting SIM800L GSM module to Arduino UNO The two pins of a speaker can be tied directly to these two pins. SPK± is a differential speaker interface. The two microphone pins can be connected directly to these pins. Pulling it HIGH will put module in sleep mode, disabling serial communication.
It can also be configured to pulse when an SMS is received.ĭTR pin activates/deactivates sleep mode. It is by default high and will pulse low for 120ms when a call is received. It is basically the ‘interrupt’ out pin from the module. GND is the Ground Pin and needs to be connected to GND pin on the Arduino. TxD (Transmitter) pin is used for serial communication. RxD (Receiver) pin is used for serial communication. If you absolutely got the module in a bad space, pull this pin low for 100ms to perform a hard reset. Remember connecting it to 5V pin will likely destroy your module! It doesn’t even run on 3.3 V! An external power source like Li-Po battery or DC-DC buck converters rated 3.7V 2A would work. This can be anywhere from 3.4V to 4.4 volts. NET is a pin where you can solder Helical Antenna provided along with the module.