How to Connect SIM800L to ESP32 | GSM Setup & Network Test (GSM IoT Series #1)

Published at : 23 Dec 2025

Read the Full Guide & Copy the Code: https://iotbhai.io/how-to-connect-sim800l-to-esp32-gsm/

Learn how to add cellular connectivity to your ESP32 projects using the SIM800L GSM Module! In Part 1 of this IoT Series, we "Forget Wi-Fi" and set up the hardware to connect to a mobile network.
We cover the critical power supply requirements (18650 battery + Capacitor), the wiring diagram, and the basic code using the TinyGSM library to check signal quality.

Watch SIMA7670G 4G Setup with ESP32: https://youtu.be/nEujkim3-HA
Next Episode Preview: Sending SMS

**Hardware Used:**
* ESP32 Development Board (38-pin)
* SIM800L GSM Module (Micro SIM)
* 18650 Li-ion Battery (3.7V) & Holder
* 470uF or 1000uF Capacitor (Crucial!)
* Custom PCB or Breadboard

**Key Topics Covered:**
* Why use GSM instead of Wi-Fi for IoT?
* Powering the SIM800L correctly (2A Peak handling)
* Wiring ESP32 to SIM800L (TX, RX, RST, DTR)
* Understanding LED Status Blinks (NetLight)
* TinyGSM Library Setup & Network Test Code

** Timestamps:**
00:00 - Introduction: The Cellular IoT Series
01:00 - Roadmap: SMS, Calls, MQTT, GPS Tracker
02:30 - Circuit Diagram & PCB Overview
03:30 - Components: Battery, SIM Card, ESP32
04:45 - SIM800L Module Overview & Power Requirements
08:00 - Pinout & Wiring Explanation (TX/RX)
09:15 - Code Walkthrough: TinyGSM & Configuration
11:45 - Defining Pins & Setup Loop
14:40 - Uploading Code & Serial Monitor Demo
16:20 - Understanding the LED Blink Codes (Network Status)

Code Link -https://github.com/ittipu/IoT_Bhai_Youtube_Channel/blob/main/SIM800L%20With%20ESP32(English)/1.%20ESP32%20%26%20SIM800L%20Circuit%20Setup%20Configuration%20%20Network%20Testing/esp32_SIM800L_Network_Testing/esp32_SIM800L_Network_Testing.ino

Libraries Used:
PubSubClient library - http://pubsubclient.knolleary.net/
TinyGsmClient library - https://github.com/vshymanskyy/TinyGSM
ArduinoJson library - https://arduinojson.org/?utm_source=meta&utm_medium=library.properties
TimeLib library - https://playground.arduino.cc/Code/Time/

Upcoming Episode Preview
- Sending and receiving SMS messages
- MQTT integration
- HTTP requests
- Google Firebase connectivity
- GPS functionality with the Ublox NEO-M8N
- Making calls
- OTA (Over-the-Air) updates
- API endpoint integration
- Building a GPS tracker
And much more!

**Related Topics:**
ESP32 GSM Tutorial, SIM800L Power Supply, TinyGSM Arduino, Cellular IoT Project, ESP32 GPS Tracker, Arduino SIM800L.

Stay tuned for the next video, where we'll dive into SMS! Don't forget to like, subscribe, and hit the notification bell so you don't miss out!

#esp32 #esp32project #sim800l #gsm #gps #iot #iotprojects #arduino #arduinoproject #tutorial #mqtt #embeddedsystems #gsmodules