QuectelEC200U Module

Arduino library for Quectel EC200U (CN-AA firmware) providing a robust AT-command wrapper and advanced examples for easier integration of cellular connectivity into your projects.

Repository: https://github.com/MISTERNEGATIVE21/QuectelEC200U

Where to Buy

Sharvi Electronics ESP32-S3 with EC200U: Buy Here

More information on Custom ESP32-S3 with EC200U: Sharvi Electronics ESP32-S3 with EC200U

Capuf EC200U-CN Module: Buy Here

More information on Capuf Module: Capuf Module

Features

Unified Hardware Abstraction Layer (HAL): Multi-MCU support (QuectelHAL.h) covering ESP32, RP2040/RP2350 Pico, STM32, Teensy, AVR, SAMD, and Zephyr RTOS.
Non-Blocking Core Async Engine: Non-blocking tick() method to continuously poll UART, parse URCs, and handle state transitions asynchronously.
Asynchronous URC Callbacks: Event-driven callbacks for incoming SMS (onSMS), voice calls (onCall), MQTT messages (onMQTT), network registration changes (onNetwork), and raw TCP socket notifications (onTCPData).
Structured Diagnostic Logging: Configurable log severity (NONE, ERROR, WARN, INFO, DEBUG) and customizable output stream routing (setDebugStream).
Revamped Gzip WebUI Hotspot: Sleek dark glassmorphism dashboard UI compressed with Gzip (index_html_gz.h) served directly from PROGMEM for instant loads.
Core & State Management: Modem initialization, AT command interface, state tracking.
Network: SIM/registration, PDP attach/activation, signal strength (CSQ/RSSI), operator info.
TCP/IP & Sockets: Raw TCP socket management (QIOPEN/QISEND/QIRD).
SSL/TLS: Secure sockets (QSSLCFG/QSSLOPEN), CA certificate provisioning.
HTTP/HTTPS: GET and POST requests with TLS support.
MQTT: Connect, publish, subscribe, disconnect with optional SSL/TLS encryption.
SMS: Send, read, delete, and count SMS messages.
Voice Calls: Dial, answer, hang up, list calls, and manage speaker/microphone levels.
USSD: Send and receive USSD messages.
GNSS: Start/stop, get location (NMEA sentence or parsed GNSSData), and configure GNSS.
NTP & Time: Synchronize time with NTP servers, get/set module RTC clock.
Filesystem: List, upload, read, and delete files on module storage.
TTS (Text-to-Speech): Play text as speech.
FTP: Login, download files, and logout.
Audio: Speaker volume, mic gain, sidetone, and audio routing.
Power Management: Power save mode (PSM), power off, and hardware reboot.

Installation

Download the latest release from the GitHub repository.
In the Arduino IDE, go to Sketch > Include Library > Add .ZIP Library... and select the downloaded file.
The library will be available in Sketch > Include Library > QuectelEC200U.

Getting Started

Here is a simple example of how to initialize the modem, connect to the network, and make an HTTP GET request.

#include <QuectelEC200U.h>

// Define pins for your board
#define EC200U_RX_PIN 16
#define EC200U_TX_PIN 17

#if defined(ARDUINO_ARCH_ESP32)
  HardwareSerial SerialAT(1);
  QuectelEC200U modem(SerialAT, 115200, EC200U_RX_PIN, EC200U_TX_PIN);
#elif defined(ARDUINO_ARCH_ZEPHYR)
  HardwareSerial& SerialAT = Serial1;
  QuectelEC200U modem(SerialAT, 115200, EC200U_RX_PIN, EC200U_TX_PIN);
#else
  #include <SoftwareSerial.h>
  SoftwareSerial SerialAT(7, 8); // RX, TX
  QuectelEC200U modem(SerialAT);
#endif

void setup() {
  Serial.begin(115200);
  
  #if defined(ARDUINO_ARCH_ZEPHYR)
    SerialAT.begin(115200);
  #elif !defined(ARDUINO_ARCH_ESP32)
    SerialAT.begin(9600); // SoftwareSerial default
  #endif

  Serial.println("Initializing modem...");
  if (modem.begin()) {
    Serial.println("Modem initialized.");
  } else {
    Serial.print("Failed to initialize modem. Error: ");
    Serial.println(modem.getLastErrorString());
    while (1);
  }

  Serial.println("Waiting for network...");
  if (modem.waitForNetwork()) {
    Serial.println("Network connected.");
  } else {
    Serial.print("Failed to connect to network. Error: ");
    Serial.println(modem.getLastErrorString());
    while (1);
  }

  Serial.println("Attaching to data network...");
  modem.attachData("your.apn"); // Replace with your APN

  String response;
  Serial.println("Performing HTTP GET...");
  if (modem.httpGet("http://example.com", response)) {
    Serial.println("Response:");
    Serial.println(response);
  } else {
    Serial.print("HTTP GET failed. Error: ");
    Serial.println(modem.getLastErrorString());
  }
}

void loop() {
  // Your code here
}

Default Pin Definitions

Most ESP32 examples share the same wiring so you can copy/paste between sketches:

Signal	ESP32 Pin	Description
`EC200U_RX_PIN`	16	Connects to the modem TX (ESP32 receives data)
`EC200U_TX_PIN`	17	Connects to the modem RX (ESP32 transmits data)
`EC200U_PWRKEY_PIN`	10	Drive LOW for ~2 s to toggle modem power
`EC200U_STATUS_PIN`	2	Optional status feedback (HIGH when modem is on)

Update the macros at the top of each sketch if your carrier board routes the modem elsewhere. Non‑ESP32 boards still use the same macro names so the documentation stays consistent.

MCU Support Matrix (`QuectelHAL.h`)

The library includes a cross-platform Hardware Abstraction Layer (QuectelHAL.h) that automatically adapts GPIO management, time functions (millis/delay), memory queries (freeHeap), and chip identifiers across various microcontroller architectures:

Platform / MCU	Architecture Macro	Recommended Serial	Supported Features
ESP32 / ESP32-S3 / ESP32-C3	`ARDUINO_ARCH_ESP32`	`HardwareSerial`	Full (AT Commands, Async Engine, URC Callbacks, WebUI Hotspot)
Raspberry Pi Pico / Pico 2	`ARDUINO_ARCH_RP2040` / `ARDUINO_ARCH_RP2350`	`SerialUART` / `HardwareSerial`	Full (AT Commands, Async Engine, URC Callbacks, WebUI Hotspot)
STM32	`ARDUINO_ARCH_STM32`	`HardwareSerial`	Full (AT Commands, Async Engine, URC Callbacks)
Teensy 3.x / 4.x	`TEENSYDUINO`	`HardwareSerial`	Full (AT Commands, Async Engine, URC Callbacks)
Arduino SAMD (Zero/MKR)	`ARDUINO_ARCH_SAMD`	`Uart` / `HardwareSerial`	Full (AT Commands, Async Engine, URC Callbacks)
Arduino AVR (Uno/Mega)	`ARDUINO_ARCH_AVR`	`SoftwareSerial` / `HardwareSerial`	Core AT Commands, Async Engine, URC Callbacks
Zephyr RTOS	`ARDUINO_ARCH_ZEPHYR`	`HardwareSerial`	Core AT Commands, Async Engine, URC Callbacks

Non-Blocking Async Engine & URC Callbacks

Starting in v4.0.0, QuectelEC200U includes an asynchronous event engine driven by modem.tick(). Call modem.tick() inside your loop() to continuously parse incoming serial data and trigger registered URC callbacks without blocking user code.

URC Callback Setup Example

#include <QuectelEC200U.h>

#if defined(ARDUINO_ARCH_ESP32)
  HardwareSerial SerialAT(1);
  QuectelEC200U modem(SerialAT, 115200, 16, 17);
#else
  HardwareSerial& SerialAT = Serial1;
  QuectelEC200U modem(SerialAT);
#endif

void setup() {
  Serial.begin(115200);
  if (!modem.begin()) {
    Serial.println("Modem init failed!");
    while(1);
  }

  // Handle incoming SMS (+CMTI)
  modem.onSMS([](const String& sender, const String& body) {
    Serial.printf("SMS Received from %s: %s\n", sender.c_str(), body.c_str());
  });

  // Handle incoming Voice Calls (RING / +CLIP)
  modem.onCall([](const String& number, bool ringing) {
    if (ringing) {
      Serial.printf("Incoming Call from: %s\n", number.c_str());
    } else {
      Serial.println("Call disconnected.");
    }
  });

  // Handle incoming MQTT messages (+QMTRECV)
  modem.onMQTT([](const String& topic, const String& payload) {
    Serial.printf("MQTT [%s] -> %s\n", topic.c_str(), payload.c_str());
  });

  // Handle Network Registration updates (+CREG/+CGREG/+CEREG)
  modem.onNetwork([](bool registered, int stat) {
    Serial.printf("Network Registration Changed: %s (Status: %d)\n",
                  registered ? "REGISTERED" : "SEARCHING", stat);
  });
}

void loop() {
  // Non-blocking tick: processes UART buffer and dispatches callbacks
  modem.tick();
}

Indian APN Settings

For users in India, you may need to set the APN (Access Point Name) for your mobile carrier. Here is a list of common APNs:

Jio: jionet
Airtel: airtelgprs.com
Vodafone Idea (Vi): www
BSNL: bsnlnet

You can use the getOperator() function to identify the network and then set the APN accordingly. For a detailed example, see examples/Indian_APN_Demo/Indian_APN_Demo.ino.

PPPoS (Point-to-Point Protocol over Serial)

This library can be used with the PPPOSClient library to establish a PPP connection with the EC200U modem. This allows you to use standard networking libraries like WiFiClient and HTTPClient over the cellular connection.

For a detailed example, see examples/PPPOS_Demo/PPPOS_Demo.ino.

TCP Socket Example

For raw sockets (e.g. pushing bytes to a custom server), the pattern is the same: bring up data, open a socket with tcpOpen, send with tcpSend, and read with tcpRecv. The new examples/TCP_Client_Quickstart/TCP_Client_Quickstart.ino sketch contains a full walk-through; the core loop looks like this:

const char HOST[] = "postman-echo.com";
int socketId = modem.tcpOpen(HOST, 80, 1, 0);
if (socketId >= 0) {
  modem.tcpSend(socketId, "GET /get HTTP/1.1\r\nHost: postman-echo.com\r\n\r\n");
  String response;
  if (modem.tcpRecv(socketId, response, 1024, 8000)) {
    Serial.println(response);
  }
  modem.tcpClose(socketId);
}

HTTPS Example

To talk to HTTPS endpoints you must provision a CA certificate once, configure an SSL context, and then call httpsGet/httpsPost. See examples/HTTPS_Client_Quickstart/HTTPS_Client_Quickstart.ino for a ready-to-run sketch. The critical steps are:

modem.sslUploadCert(cloudflare_ca_cert, "cloudflare.pem");
modem.sslConfigure(1, "cloudflare.pem");

String response;
if (modem.httpsGet("https://www.cloudflare.com/", response)) {
  Serial.println(response);
} else {
  Serial.println(modem.getLastErrorString());
}

Experimental Examples

Under the examples/experimental/ folder, you will find more complex demos that rely on third-party integrations or external libraries:

1. Consentium IoT Telemetry (`Consentium_IoT_Demo`)

Uploads JSON telemetry data over a secure socket. It loads the Consentium IoT TLS cert, configures SSL (sslConfigure), and posts metrics to https://api.consentiumiot.com. It can optionally set a receiveKey to fetch recent updates immediately after sending.

How to Add Sensor Data (Add Telemetry): In the Consentium_IoT_Demo sketch, adding telemetry data for Consentium IoT is easy. You simply update the SENSORS array with your sensor's name and value string:

static const SensorEntry SENSORS[] = {
  {"Temperature", "25.50"}, // Replace hardcoded value with your reading
  {"Humidity", "60.00"},
  {"Custom Sensor", "1023"},
  {"", ""},
  {"", ""}
};

The demo automatically bundles these into the standard Consentium IoT JSON payload structure.

2. Telegram Bot (`Telegram_Bot_Demo`)

Demonstrates using the new QuectelTelegramBot helper class to natively interact with the Telegram API. Instead of relying on unwieldy external Wi-Fi libraries or PPPoS, this lightweight class hooks directly into the modem's built-in httpsGet and httpsPost commands. It easily processes incoming JSON updates and handles sending messages effortlessly.

WebUI Hotspot API

The WebUI Hotspot example has grown into a full control panel with REST endpoints you can also script against:

Endpoint	Purpose
`GET /api/status`	Adds RSRP/RAT details, APN origin, and MQTT summary fields.
`GET /api/device/sensors`	Battery status (`+CBC` percent/voltage) plus on-board ADC sample.
`GET/POST /api/pdp/*`	Inspect PDP selection, activate/deactivate a context, or clear a saved APN.
`GET/POST /api/mqtt/*`	Track broker state, connect with APN overrides, publish payloads, and subscribe to topics.
`GET /api/call/status`, `POST /api/call/answer`, `POST /api/call/volume`	Surface active calls, answer incoming rings, and bump speaker volume from the UI.

The corresponding frontend now shows a Power & Sensors card, PDP controls, MQTT client section, and a richer Phone tab (answer button, live log, and speaker volume slider). These APIs are ideal for integrating the modem with external dashboards without touching the AT layer.

API Reference

Core & Async Engine

begin(bool forceReinit = false): Initializes the modem.
tick(): Non-blocking execution loop. Polls UART, parses URC responses, and triggers registered callbacks.
onSMS(SMSCallback cb): Register callback for incoming SMS (void(const String& sender, const String& body)).
onCall(CallCallback cb): Register callback for voice call events (void(const String& number, bool ringing)).
onMQTT(MQTTCallback cb): Register callback for MQTT messages (void(const String& topic, const String& payload)).
onNetwork(NetworkCallback cb): Register callback for network registration changes (void(bool registered, int stat)).
onTCPData(TCPDataCallback cb): Register callback for raw TCP socket data (void(int connectID, int length)).
onURC(URCCallback cb): Register fallback callback for unhandled URCs (void(const String& urc)).
sendAT(const String &cmd, const String &expect = "OK", uint32_t timeout = 3000): Sends an AT command.
readResponse(char* buffer, size_t length, uint32_t timeout): Reads the response from the modem into the provided buffer.
getIMEI(): Gets the modem's IMEI.
getModemInfo(): Gets information about the modem.
factoryReset(): Resets the modem to factory defaults.
powerOff(): Powers off the modem.
reboot(): Reboots the modem.

Diagnostic Logging

setLogLevel(QuectelLogLevel level): Sets log severity (QUECTEL_LOG_LEVEL_NONE, ERROR, WARN, INFO, DEBUG).
setDebugStream(Stream &debugStream): Configures diagnostic logging output stream.
enableDebug(Stream &debugStream): Enables debug logging output.

Hardware Abstraction Layer (`QuectelHAL.h`)

QUECTEL_HAL_SERIAL_TYPE: Platform-specific Serial type (HardwareSerial, SerialUART, or SoftwareSerial).
QUECTEL_HAL_SERIAL_INIT(name, rx, tx): Instantiates the hardware or software serial object.
QUECTEL_HAL_SERIAL_BEGIN(name, baud, rx, tx): Initializes serial port baud rate and pin mapping across architectures.
QUECTEL_DELAY_MS(ms): Platform delay abstraction calling vTaskDelay or yield() on RTOS targets.
QUECTEL_PIN_MODE(pin, mode), QUECTEL_DIGITAL_WRITE(pin, val), QUECTEL_DIGITAL_READ(pin): GPIO control macros.
QUECTEL_PROGMEM: Memory macro for flash storage across AVR, ARM Cortex-M, and Xtensa.
quectelPowerPulse(pin, activeLevel, pulseMs): Helper to toggle PWRKEY or RESET pins reliably without blocking CPU.

Network

waitForNetwork(uint32_t timeoutMs = 60000): Waits for the modem to register on the network.
attachData(const String &apn, const String &user = "", const String &pass = "", int auth = 0): Attaches to the data network.
activatePDP(int ctxId = 1): Activates the Packet Data Protocol context.
deactivatePDP(int ctxId = 1): Deactivates the PDP context.
getRegistrationStatus(bool eps = true): Gets the network registration status.
isSimReady(): Returns true if the SIM card is ready.
getOperator(): Gets the name of the network operator.
getSignalStrength(): Gets the signal strength (RSSI).
setAPN(const String &apn): Sets the Access Point Name (APN).

HTTP/HTTPS

httpGet(const String &url, String &response): Performs an HTTP GET request.
httpPost(const String &url, const String &data, String &response): Performs an HTTP POST request.
httpsGet(const String &url, String &response): Performs an HTTPS GET request. Note: You must call sslConfigure() before using this function.
httpsPost(const String &url, const String &data, String &response): Performs an HTTPS POST request. Note: You must call sslConfigure() before using this function.

MQTT

mqttConnect(const String &server, int port): Connects to an MQTT broker.
mqttPublish(const String &topic, const String &message): Publishes a message to an MQTT topic.
mqttSubscribe(const String &topic): Subscribes to an MQTT topic.
mqttDisconnect(): Disconnects from the MQTT broker.

TCP Sockets

tcpOpen(const String &host, int port, int ctxId = 1, int socketId = 0): Opens a TCP socket.
tcpSend(int socketId, const String &data): Sends data over a TCP socket.
tcpRecv(int socketId, String &out, size_t bytes = 512, uint32_t timeout = 5000): Receives data from a TCP socket.
tcpClose(int socketId): Closes a TCP socket.

USSD

sendUSSD(const String &code, String &response): Sends a USSD code.

NTP & Time

ntpSync(const String &server = "pool.ntp.org", int timezone = 0): Synchronizes the time with an NTP server.
getClock(): Gets the current time from the modem.
setClock(const String &datetime): Sets the time on the modem.

GNSS

startGNSS(): Starts the GNSS receiver.
stopGNSS(): Stops the GNSS receiver.
isGNSSOn(): Returns true if the GNSS receiver is on.
setGNSSConfig(const String &item, const String &value): Configures a GNSS parameter.
getNMEASentence(const String &type = "RMC"): Gets a raw NMEA sentence.
getGNSSLocation(): Gets the parsed GNSS location.
getGNSSLocation(uint32_t fixWaitMs): Gets the parsed GNSS location, waiting for a fix.

Text-to-Speech (TTS)

playTTS(const String &text): Plays the given text as speech.

FTP

ftpLogin(const String &server, const String &user, const String &pass): Logs in to an FTP server.
ftpDownload(const String &filename, String &data): Downloads a file from the FTP server.
ftpLogout(): Logs out from the FTP server.

Filesystem

fsList(String &out): Lists the files on the modem's filesystem.
fsUpload(const String &path, const String &content): Uploads content to a file.
fsRead(const String &path, String &out, size_t length = 0): Reads a file.
fsDelete(const String &path): Deletes a file.
fsExists(const String &path): Checks if a file exists.

SSL/TLS

sslConfigure(int ctxId, const String &caPath, bool verify = true): Configures SSL/TLS for a context.

Power Management

enablePSM(bool enable): Enables or disables Power Save Mode (PSM).

Audio

setSpeakerVolume(int level): Sets the speaker volume.
setRingerVolume(int level): Sets the ringer volume.
setMicMute(bool mute): Mutes or unmutes the microphone.
setMicGain(int channel, int level): Sets the microphone gain.
setSidetone(bool enable, int level): Enables or disables sidetone.
setAudioChannel(int channel): Sets the audio channel.
setAudioInterface(const String &params): Configures the audio interface.
audioLoopback(bool enable): Enables or disables audio loopback.

Constructors

The library provides two constructors to accommodate different hardware setups:

HardwareSerial

For boards like ESP32, you can use a HardwareSerial port. You can also specify the RX and TX pins.

#include <QuectelEC200U.h>

HardwareSerial& SerialAT = Serial1;
QuectelEC200U modem(SerialAT, 115200, /* RX */ 16, /* TX */ 17);

Stream

For other boards or configurations (e.g., SoftwareSerial), you can use any Stream object.

#include <SoftwareSerial.h>
#include <QuectelEC200U.h>

SoftwareSerial SerialAT(7, 8); // RX, TX
QuectelEC200U modem(SerialAT);

State Management

The library uses a state machine to track the modem's status. You can get the current state using modem.getState(). The possible states are:

MODEM_UNINITIALIZED: The modem has not been initialized.
MODEM_INITIALIZING: The modem is currently initializing.
MODEM_READY: The modem is initialized and ready to receive commands.
MODEM_ERROR: An error occurred during initialization. Use getLastError() or getLastErrorString() to get more information.
MODEM_NETWORK_CONNECTED: The modem is registered on the network.
MODEM_DATA_READY: The modem has an active data connection.

Debugging

You can enable debug messages to a Stream object (e.g., Serial) to get more insight into the library's operation.

void setup() {
  Serial.begin(115200);
  modem.enableDebug(Serial);
  // ...
}

Contributing

Contributions are welcome! Please open an issue or submit a pull request on the GitHub repository.

Maintainer

MisterNegative21 misternegative21@gmail.com

License

This library is released under the MIT License. See the LICENSE file for details.

Trademarks & Attribution

Quectel, EC200U, and related marks are trademarks or registered trademarks of Quectel Wireless Solutions Co., Ltd. This library is unofficial and not affiliated with Quectel.

Changelog

The full release history and library updates have been moved to the CHANGELOG.md file. Please refer to it for all recent improvements!

Name		Name	Last commit message	Last commit date
assets		assets
docs		docs
examples		examples
src		src
.gitattributes		.gitattributes
.gitignore		.gitignore
AUTHORS.md		AUTHORS.md
CHANGELOG.md		CHANGELOG.md
LICENSE		LICENSE
NOTICE		NOTICE
README.md		README.md
capuf.png		capuf.png
circuit_image.png		circuit_image.png
fix_examples.py		fix_examples.py
keywords.txt		keywords.txt
library.properties		library.properties
patch_quectel.py		patch_quectel.py

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