Log Sensor Data to Blynk Server Using GPRS on TTGO ESP32 SIM800L

Introduction

Internet is the main key for Internet of Things project and normally we will use WiFi as the connection. However, sometimes, you need to place your IoT project for a long time and no WiFi coverage at that area. I mean, set your smartphone as hotspot is not practical for this case. To solve this problem, you can consider GPRS. Just bought a SIM card with data plan (no need much quota) and use it with TTGO T-Call ESP32 SIM800L. So in this tutorial, I will share with on how to log sensor data to blynk server using GPRS. Then, export the data in CSV format for further analysis.

Video

This video shows how to log sensor data to Blynk server using GPRS on TTGO T-Call ESP32 SIM800L.

Hardware Preparation

This is the list of items used in the video.

• TTGO T-Call ESP32 with SIM800L GPRS Module
• MPL3115A2 I2C Barometric/Altitude/Temperature Sensor

Sensor Connection

TTGO T-Call ESP32 Breakout PCB

If you have Snapmaker, you can download - THIS FILES, and use it for CNC your PCB.

Sample Program

This is Arduino sample program to send sensor data to Blynk server using GPRS. Please make sure your SIM card have data plan. Before compile, please install following libraries on Library Manager.

• Adafruit MPL3115A2 Library by Adafruit Version 1.2.2
• Blynk by Volodymyr Shymanskyy Version 0.6.1
• TinyGSM by Volodymyr Shymanskyy Version 0.7.9

Thank You

References:

• TTGO T CALL - Blynk App GSM | ESP32 SIM800L
• ESP32 Publish Data to Cloud without Wi-Fi (TTGO T-Call ESP32 SIM800L)

Thanks for reading this tutorial. If you have any technical inquiries, please post at Cytron Technical Forum.