> For the complete documentation index, see [llms.txt](https://cocolinx.gitbook.io/cocolinx-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cocolinx.gitbook.io/cocolinx-docs/home/english/development/eg800ak-getting-started.md).

# EG800AK | Getting Started

한글 버전: <https://blog.naver.com/cocolinx/224330497872>

## 1. Preperations

### Requirements

* CocoLinx-EG800AK
* Jumper wire
* Arduino UNO R4 or MCU board

### Set up your board

1. Insert the nano-SIM card into the nano-SIM card slot.
2. Attach the included U.FL cabled LTE-M Antenna.
3. Connect the CocoLinx-EG800AK module to an Arduino or MCU board using jumper wires. The **EN** and **RST** pins may be left unconnected.

## 2. Essential Hardware Setup

### Power Supply

Supply the CocoLinx-EG800AK module with a stable voltage between **3.0 V and 5.5 V**. Make sure the power source can provide sufficient current during LTE transmission.

### PWR Pin

To turn on the module, drive the **PWR pin High for about 1 second** after the power supply has been applied.

### UART Logic Voltage (VIO)

The **VIO pin** sets the UART logic voltage level of the module. Apply a voltage between **1.8 V and 5.0 V** to the VIO pin, matching the UART logic level of the connected Arduino or MCU board.

## 3. Arduino Easy Test

The CocoLinx-EG800AK module can be tested with an Arduino in two ways. First, use the UART Bridge Test to verify that the module powers on correctly and responds to basic AT commands. Then, use the Arduino Library Test to test network registration and communication features through the CocoLinx Arduino library.

### UART Bridge Test

The UART Bridge Test is a simple hardware verification test. It is used to confirm

* The module powers on correctly.
* The PWR pin is controlled properly.
* The UART wiring is correct.
* The module responds to basic AT commands.

In this test, the Arduino acts as a UART bridge between the PC and the CocoLinx-EG800AK module. Commands entered in the Arduino Serial Monitor are forwarded directly to the module, and the module's responses are displayed on the Serial Monitor.

This test does not require the CocoLinx-EG800AK Arduino library.

Just put this code in your Arduino UNO board.

```cpp
constexpr int MODEM_PWR_PIN = 7;

void setup() {
  Serial.begin(115200);
  Serial1.begin(115200);

  pinMode(MODEM_PWR_PIN, OUTPUT);

  digitalWrite(MODEM_PWR_PIN, LOW);
  delay(100);

  digitalWrite(MODEM_PWR_PIN, HIGH);
  delay(1500);

  digitalWrite(MODEM_PWR_PIN, LOW);
  delay(100);

  Serial.println("AT UART bridge start");
}

void loop() {
  // Modem -> PC
  while (Serial1.available()) {
    Serial.write(Serial1.read());
  }

  // PC -> Modem
  while (Serial.available()) {
    Serial1.write(Serial.read());
  }
}

```

After uploading the UART bridge sketch, open the Serial Monitor and send:

```
AT
```

If the module is powered and connected correctly, it should respond with:

```
OK
```

Once the `OK` response is received, the basic power and UART connection are working correctly.

### Arduino Library Test

After completing the UART Bridge Test, install the [CocoLinx EG800AK AT Parser Library for Arduino](https://github.com/cocolinx/eg800ak-at-parser-arduino) and run one of the included examples.

The library test can be used to verify functions such as:

* AT command communication
* Network registration
* Signal quality reading
* UDP, TCP, and MQTT communication

Open an example from the Arduino IDE, select the correct board and port, and upload the sketch. Then open the Serial Monitor to check the test results.