LILYGO TTGO T-Call SIM800H ESP32 Wireless Module SIM Antenna WiFi Bluetooth TTGO Development Board Expand Board
 
The LILYGO TTGO T-Call is an ESP32-based development board integrating a SIM800H (or SIM800L) GSM/GPRS module, designed for IoT projects requiring cellular connectivity. It features 240MHz dual-core processing, Wi-Fi 4, Bluetooth, USB-C, and a Nano SIM slot, allowing for SMS, calls, and internet data over 2G networks. 
 
Key Features and Specifications:
MCU: ESP32-WROVER-B (240 MHz dual-core, 520KB SRAM, 8MB PSRAM, 4MB Flash).
Cellular Module: SIM800H  (2G GSM/GPRS).
Connectivity: Wi-Fi 802.11 b/g/n, Bluetooth 4.2 BR/EDR and BLE.
Power Management: USB Type-C (5V) and Li-Po battery connector (3.7V) with integrated battery charger.
Interfaces: I2C, SPI, UART, SDIO, I2S, CAN, and Nano SIM slot.
Antenna: Includes an external antenna for enhanced signal strength. 
 
Common Use Cases:
IoT applications without Wi-Fi router coverage.
Remote data logging (e.g., sending sensor data to a cloud server).
SMS-based alerts and monitoring. 
 
Development and Usage:
Programming: Compatible with Arduino IDE and Espressif IoT Development Framework (ESP-IDF).
Library: Supports the LilyGo-T-Call-SIM800 GitHub repository.
Setup Requirements: Requires an active Nano SIM card with 2G data/voice support.
Version Note: Different versions exist (e.g., V1.3, V1.4), with some using the SIM800H and others the SIM800L, often utilizing the IP5306 power management chip.