How to Use Air780EU (Schematic): Examples, Pinouts, and Specs

The Air780EU is a compact and efficient cellular module designed specifically for Internet of Things (IoT) applications. It provides LTE connectivity with low power consumption, making it ideal for battery-powered devices. The module supports multiple communication protocols, including TCP/IP, MQTT, and HTTP, enabling seamless integration into remote monitoring and control systems. Its small form factor and robust design make it suitable for a wide range of applications, such as smart meters, asset tracking, industrial automation, and environmental monitoring.

Below are the key technical details and pin configuration of the Air780EU module:

The Air780EU module has a total of 24 pins. Below is the pinout description:

1. Power Supply: Connect the VCC pin to a stable power source (3.3V to 4.2V) and GND to the ground of your circuit.
2. UART Communication: Use the TXD and RXD pins to establish serial communication with a microcontroller or host device. Ensure the baud rate matches the module's default setting (typically 115200 bps).
3. Antenna Connection: Attach an external antenna to the ANT pin for optimal signal reception.
4. Power-On Sequence: Pull the PWRKEY pin low for at least 1 second to power on the module.
5. Network Status: Monitor the NET_STATUS pin to check the module's connection status.
6. SIM Card: Insert a compatible SIM card and connect the SIM_DET pin to detect its presence.

• Use decoupling capacitors near the VCC pin to ensure stable power delivery.
• Avoid placing the antenna near high-frequency components to minimize interference.
• Ensure proper grounding to reduce noise and improve signal quality.
• Use level shifters if interfacing with a microcontroller operating at a different voltage level.

Below is an example of how to connect the Air780EU to an Arduino UNO and send an AT command to check the module's status:

#include <SoftwareSerial.h>

// Define software serial pins for Air780EU communication
SoftwareSerial air780Serial(2, 3); // RX, TX

#define PWRKEY_PIN 4 // Pin connected to PWRKEY

void setup() {
  // Initialize serial communication
  Serial.begin(9600); // For debugging
  air780Serial.begin(115200); // For Air780EU communication

  // Configure PWRKEY pin
  pinMode(PWRKEY_PIN, OUTPUT);
  digitalWrite(PWRKEY_PIN, HIGH); // Set PWRKEY high initially

  // Power on the Air780EU module
  Serial.println("Powering on Air780EU...");
  digitalWrite(PWRKEY_PIN, LOW); // Pull PWRKEY low
  delay(1000); // Hold for 1 second
  digitalWrite(PWRKEY_PIN, HIGH); // Release PWRKEY
  delay(5000); // Wait for the module to initialize

  // Send an AT command to check module status
  Serial.println("Sending AT command...");
  air780Serial.println("AT");
}

void loop() {
  // Read and display responses from the Air780EU module
  if (air780Serial.available()) {
    String response = air780Serial.readString();
    Serial.println("Air780EU Response: " + response);
  }
}

1. Module Not Powering On

   • Ensure the PWRKEY pin is pulled low for at least 1 second during the power-on sequence.
   • Verify that the power supply voltage is within the specified range (3.3V to 4.2V).

2. No Response to AT Commands

   • Check the UART connections (TXD and RXD) and ensure they are not swapped.
   • Confirm that the baud rate of the microcontroller matches the module's default baud rate (115200 bps).

3. Poor Signal Reception

   • Ensure the antenna is securely connected to the ANT pin.
   • Avoid placing the module in areas with significant electromagnetic interference.

4. SIM Card Not Detected

   • Verify that the SIM card is properly inserted and compatible with the module.
   • Check the SIM_DET pin connection.

Q: Can the Air780EU operate on 5V logic levels?
A: No, the Air780EU operates on 3.3V logic levels. Use level shifters if interfacing with a 5V microcontroller.

Q: What is the typical startup time for the module?
A: The Air780EU typically takes 3-5 seconds to initialize after powering on.

Q: Does the module support GPS functionality?
A: No, the Air780EU does not include GPS functionality. It is designed for LTE connectivity only.