1. Introduction
The SIMCOM A7670 series core boards are advanced LTE Cat 1 modules designed for a wide range of telecommunications applications. These modules support various wireless communication modes including LTE-TDD, LTE-FDD, G-SM, GPRS, and EDGE. They are capable of achieving a maximum downlink rate of 10Mbps and an uplink rate of 5Mbps. The modules can be controlled via AT Commands and offer rich interfaces such as UART and USB2.0. Optional GNSS functionality is available for precise positioning applications. The operating temperature range is from -40°C to +85°C, ensuring reliable performance in diverse environments.
This manual provides detailed instructions for the setup, operation, and troubleshooting of your A7670 series core board.
2. Product Overview
2.1 Module Features
- LTE Cat 1 Module: Supports LTE-TDD/LTE-FDD/G-SM/GPRS/EDGE wireless communication modes.
- High Data Rates: Up to 10Mbps downlink and 5Mbps uplink.
- Control Interface: Via AT Command.
- Rich Interfaces: Including UART, USB2.0.
- Wide Operating Temperature: -40°C to +85°C.
- GNSS: Optional support for Global Navigation Satellite System.
2.2 Board Overview and Dimensions
The PCBA dimension of the module is 37mm x 37mm.
Key components and interfaces:
| Component/Pin | Description |
|---|---|
| CN2 | Nano SIM card socket 1 |
| CN3 | Nano SIM card socket 2 (Optional) |
| CN101 | 7pin 2.54mm header interface |
| CN1 | USB interface |
| D5 | NET LIGHT indicator (Green) |
| U2 | The power conversion chip |
| J1 | LTE ANT |
| J2 | GPS ANT (Optional) |
| J3 | BT ANT (Optional) |
| TP1 | 4.0V Test Point |
3. Setup Instructions
Follow these steps to set up your SIMCOM A7670 series core board:
-
Install Antennas and SIM Card: Install the LTE antenna, GPS antenna (if applicable), and NanoSIM card onto the BK-A7670 Board. Ensure the SIM card is correctly inserted.
Figure 2: Example setup with A7670E Core Board, 4G Flexible Antenna, and GPS Antenna. - Power Supply: Feed power to the VCC pin. The recommended VCC range is 5.0V to 10V, with 5.0V being the recommended voltage.
-
Check Network Registration: Observe the GREEN NET LIGHT indicator (D5).
- Blinking quickly: Indicates the module is searching for a network.
- Blinking slowly: Indicates successful network registration.
- Note: Ensure a correct NB-IoT SIM card is inserted for proper operation.
3.1 Pin Definition of 6-pin Connector
| Pin Name | Pin Number | Mark on PCB | Description | Comment |
|---|---|---|---|---|
| SLEEP | 0 | S | Control module into sleep mode | Connect with DTR via Q4 |
| GND | 1, 6 | G | Ground | |
| VCC | 2 | V | The power supply | 5V-10V |
| PWRKEY | 3 | K | Power down | Shorted with GND via R104 by default |
| TXD | 4 | T | Transmit Data | TTL Series data Output |
| RXD | 5 | R | Receives Data | TTL Series data Input |
4. Operating Instructions
4.1 Serial Communication (TXD and RXD)
The default baud rate for serial communication is 115200bps.
To communicate with the module:
- Open a serial communication software on your host device.
- Select the correct serial port number.
- Configure the serial port settings as follows:
- Baud rate: 115200
- Data bits: 8
- Stop bits: 1
- Parity: None
- Flow Control: None
- Ensure the "SendNew" option is selected in your serial software for proper command transmission.
- You can now send AT commands to the module (e.g.,
AT+GSV) and receive responses.
5. Troubleshooting
The NETLIGHT pin status provides visual feedback on the module's operational state. Use the table below to diagnose common issues:
| NETLIGHT Pin Status | Module Status |
|---|---|
| Always On | Searching Network |
| 200ms ON, 200ms OFF | Data Transmit |
| 800ms ON, 800ms OFF | Registered network |
| OFF | Power off / Sleep |
If the module is stuck in "Searching Network" (Always On), ensure your SIM card is correctly inserted and active, and that you are in an area with network coverage. If the module is OFF, verify the power supply connection and voltage.
6. Specifications
| Attribute | Value |
|---|---|
| Type | Module |
| Origin | Mainland China |
| Condition | New |
| PCBA Dimension | 37mm x 37mm |
| Downlink Rate (Max) | 10Mbps |
| Uplink Rate (Max) | 5Mbps |
| Operating Temperature | -40°C to +85°C |
| VCC Power Supply Range | 5.0V to 10V (5.0V recommended) |
| Default Baud Rate | 115200bps |
7. Maintenance
To ensure the longevity and optimal performance of your SIMCOM A7670 series core board, follow these general maintenance guidelines:
- Keep the module clean and free from dust and debris. Use a soft, dry cloth for cleaning.
- Avoid exposing the module to extreme temperatures, humidity, or direct sunlight.
- Handle the module with care to prevent physical damage to components or connectors.
- Ensure proper ventilation when the module is in operation to prevent overheating.
- Regularly check for firmware updates from the manufacturer to improve performance and security.
8. User Tips
- When connecting antennas, ensure they are securely fastened but do not overtighten to avoid damaging the connectors.
- Always double-check the polarity and voltage of your power supply before connecting it to the VCC pin to prevent damage to the module.
- For initial testing, using a stable 5.0V power supply is highly recommended.
- If experiencing network issues, try restarting the module and verifying that the NanoSIM card is correctly provisioned for data services.
- Refer to the SIMCOM AT Command documentation for a full list of commands and their usage for advanced configurations.
9. Warranty and Support
For warranty information, technical support, or service inquiries, please contact your vendor or the manufacturer directly. Keep your purchase receipt and product serial number handy when seeking support.