// the find
Xinyuan-LilyGO/LilyGo-T-Call-SIM800
Board-support and example repo for LilyGo's T-Call boards, which pair an ESP32 with a SIM800 GSM modem and either an IP5306 or AXP192 power chip. It is for people who own one of these boards and want working Arduino, PlatformIO, or MicroPython sketches for calls, SMS, HTTP/HTTPS, and MQTT without writing the modem plumbing themselves.
- The examples cover what people usually try first on a SIM800 board: voice calls, SMS, HTTPS using the SIMCom SSL application note, MQTT, and a modem keep-alive sketch. Most are a single .ino with its own utilities.h pin map, so one file shows the whole flow.
- The IP5306 and AXP192 variants each have their own doc page, and the FAQ explains the 5V pin direction and the power-on behavior for each. That is the detail that usually costs a newcomer an afternoon.
- Schematics, the SIM800 AT command manual, and the hardware design PDF are committed next to the code, so wiring and AT reference material are available without leaving the repo.
- The bundled lib/ folder vendors TinyGSM, PubSubClient, ArduinoHttpClient, TinyGPSPlus, CayenneMQTT, and several Adafruit libraries as copies instead of declaring them as dependencies. Those copies will drift from upstream, and upstream fixes will not reach this repo until someone re-copies them.
- Choosing an example in PlatformIO means uncommenting one src_dir line in platformio.ini by hand, as README step 7 describes. This is easy to get wrong, and there is no per-example environment to select from the command line.
- The topics list esp32-idf and micropython, but the README only documents Arduino and PlatformIO, plus one MicroPython example built on the LoBo firmware. The part of the tree shown has no ESP-IDF project, and the README does not say what is supported.
- The README does not state which SIM800 firmware revisions or board revisions each example was tested on, beyond the board names in the table. A sketch that fails on your hardware gives you no way to tell whether the problem is the sketch or your board.