T-SIM7670G-S3 Quick Start

Required Libraries

Library	Version	Source
TinyGSM	Latest	GitHub
TinyGPSPlus	Latest	GitHub

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Arduino

PlatformIO (Recommended)

1. Install VS Code and the PlatformIO IDE extension
2. Clone the repository:

   git clone https://github.com/Xinyuan-LilyGO/LilyGo-Modem-Series.git

3. Open platformio.ini and select the T-SIM7670G-S3 environment
4. Click ✓ to build, connect via USB-C, click → to upload

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Arduino IDE

Board Settings

Setting	Value
Board	ESP32S3 Dev Module
Upload Speed	921600
USB CDC On Boot	Enable
CPU Frequency	240 MHz (WiFi)
Flash Size	16 MB (128Mb)
Partition Scheme	16M Flash (3MB APP/9.9MB FATFS)
PSRAM	OPI PSRAM

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Peripheral Examples

LTE Data (TinyGSM)

#define TINY_GSM_MODEM_SIM7672
#include <TinyGsmClient.h>

// SIM7670G UART: RX=4, TX=5, PWR_KEY=12
HardwareSerial modemSerial(1);
TinyGsm modem(modemSerial);

void setup() {
  Serial.begin(115200);
  modemSerial.begin(115200, SERIAL_8N1, 4, 5);
  // Power on modem
  pinMode(12, OUTPUT);
  digitalWrite(12, HIGH); delay(1000);
  digitalWrite(12, LOW);  delay(2000);

  modem.restart();
  Serial.println("Modem: " + modem.getModemInfo());
  modem.gprsConnect("your.apn", "", "");
  Serial.println("Connected: " + String(modem.isGprsConnected()));
}

void loop() { delay(1000); }

GPS (SIM7670G built-in GNSS)

void setup() {
  // modem already initialized above
  modem.enableGPS();
}

void loop() {
  float lat, lon, speed, alt;
  int vsat, usat;
  if (modem.getGPS(&lat, &lon, &speed, &alt, &vsat, &usat)) {
    Serial.printf("Lat: %.6f Lon: %.6f\n", lat, lon);
  }
  delay(2000);
}

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FAQ

Q: Upload keeps failing?
A: Hold BOOT, press and release RST, then release BOOT to enter download mode.

Q: SIM7670G not connecting?
A: Insert a valid nano SIM with LTE Cat-1 service. Connect the LTE and GPS antennas. Power on the modem using the PWR_KEY GPIO.