---
title: A7670 Eval Board Overview
description: "## Basic Overview The **A7670 Eval Board (Evaluation Board)** is a compact and practical evaluation platform designed for the **Simcom A7670 4G LTE module**. It provides all the essential interfaces and connectivity options you need to quickly bring your IoT,…"
url: "https://eicut.com/wiki/development-boards/gnss-gps/a7670-eval-board-overview/"
updated: "2026-02-15"
category: Development Boards / GNSS / GPS
---

# A7670 Eval Board Overview

## Basic Overview

The **A7670 Eval Board (Evaluation Board)** is a compact and practical evaluation platform designed for the **Simcom A7670 4G LTE module**. It provides all the essential interfaces and connectivity options you need to quickly bring your IoT, M2M, or 4G-based projects to life. With built-in Bluetooth & Wi-Fi antennas, GNSS and GSM connectors, audio interfaces, and user-friendly pin headers, the board simplifies development and reduces hardware setup time. Whether you’re testing, prototyping, or integrating into a larger system, the A7670 Eval Board makes development faster, easier, and more reliable.

## Board Resources

### Function Description

The main component and interface placement of the evaluation board is shown in the following figure:

![Annotated diagram of A7670 Eval Board](https://eicut.com/wp-content/uploads/2025/10/image1_11zon-3-1024x676.webp)
**Top view**

The detailed assignment of the peripheral interfaces on the evaluation board is as follows:

| NO. | Name |
| --- | --- |
| **1** | USB Type-C |
| **2** | Simcard Socket |
| **3** | Microphone and Speaker output |
| **4** | Bluetooth and Wi-Fi antenna |
| **5** | Level shifter chips |
| **6** | Watchdog timed disable |
| **7** | GSM UFL Antenna |
| **8** | User button |
| **9** | LEDs |
| **10** | Watchdog unit |
| **11** | 3A Buck |
| **12** | GNSS UFL Socket |

   🔗Tip

When the **Open-CPU** feature is **not in use**, always keep the **WDT Disable** jumper in place. This prevents unwanted resets triggered by the watchdog timer circuitry. 

###  Board Interfaces

The main pin placement of the evaluation board is shown in the following figure:

![A7670 Eval Board header pinout](https://eicut.com/wp-content/uploads/2025/10/image3_11zon-3-1006x1024.webp)
**Bottom header mapping**

 

| NO. | Name | Silkscreen |
| --- | --- | --- |
| **1** | SPI_CLK | CLK |
| **2** | SPI_CE | CE |
| **3** | SPI_MOSI | MOSI |
| **4** | SPI_MISO | MISO |
| **5** | GPIO_16 | GPIO16 |
| **6** | GPIO_18 | GPIO18 |
| **7** | PWRKEY | PWRKEY |
| **8** | ADC | ADC |
| **9** | 1PPS | 1PPS |
| **10** | GPIO15 | GPIO15 |
| **11** | GPIO28 | GPIO28 |
| **12** | DEBUG_RXD | RXD_LOG |
| **13** | DEBUG_TXD | TXD_LOG |
| **14** | GPIO18 | GPIO18 |
| **15** | RXD | RXD |
| **16** | TXD | TXD |
| **17** | GPIO_4 | RTS |
| **18** | AP_WAKEUP | DTR |
| **19** | GPIO_0 | RI |
| **20** | GPIO_1 | DCD |
| **21** | GPIO_3 | CTS |
| **22** | CI2C_SCL | SCL |
| **23** | CI2C_SDA | SDA |

## Board Dimensions

![A7670 Eval Board — mechanical dimensions ](https://eicut.com/wp-content/uploads/2025/10/image2_11zon-3.webp)
**Dimensioned top view in millimeters: board 78×58 mm, header spacing 70.7 mm, connector locations indicated.**

 

 

## Resource Download

- [A76XX Series AT Command Manual ](https://eicut.com/wp-content/uploads/2025/10/A76XX_Series_AT_Command_Manual_V1.12.pdf)
- [A7670E R2 Spec](https://eicut.com/wp-content/uploads/2025/10/A7670E_R2_Spec_210324-1.pdf)

## FAQ

    What module is used on this board?

The board uses the **Simcom A7670E** (or A7670C/A7670G depending on variant) — a compact **LTE Cat 1** module with 10 Mbps DL / 5 Mbps UL, fully certified for Europe, Asia, and global use.

    Does the board support Open-CPU / AT firmware development?

Yes — the A7670 series supports **Simcom Open-CPU SDK** (C programming on module). The board includes a **watchdog disable jumper** specifically for Open-CPU development to prevent unwanted resets.

    Can I connect normal SIM cards?

Yes — standard **nano-SIM (4FF)** socket with SIM detection and full power control.

    Is Bluetooth and Wi-Fi available?

Yes — the A7670E supports **Bluetooth 5.0** and **Wi-Fi 802.11b/g/n**. On-board **PCB antenna** + optional **U.FL connector** pads for external antennas.

    Is GNSS (GPS/GLONASS/BeiDou/Galileo) supported?

Yes — integrated multi-constellation GNSS with **active/passive antenna support** via dedicated **U.FL connector** and 1PPS output on header.

    What voltage levels are on the headers?

All I/O pins are **3.3 V tolerant** thanks to onboard bidirectional level shifters. Safe to connect directly to Arduino, ESP32, Raspberry Pi, STM32, etc.

    How do I power the board?

Via **USB-C** (5 V) → onboard high-efficiency **3 A buck converter** generates clean 4.2 V for the module. You can also feed 3.8–4.4 V directly to VBAT pins if needed.

    How do I access the debug / AT command port?

Two ways:
 • **USB-C** automatically enumerates as multiple COM ports (AT, NMEA, Debug, Modem)
 • Dedicated **RXD_LOG / TXD_LOG** pins on header (115200 baud) for low-level logs

    Can I use the audio jack for voice calls?

Yes — 3.5 mm TRRS jack with **mic input** and **speaker output**. Perfect for testing VoLTE or classic circuit-switched voice.

    Is this board suitable for production?

It is an **evaluation / development board**, but full **schematics, layout (KiCad), and BOM** are provided so you can easily copy the design into your own carrier board.

    Do I need the WDT Disable jumper?

Yes — when **not using Open-CPU**, keep the **WDT Disable jumper** installed. Remove it only during Open-CPU development to allow the external watchdog to reset the module if your code hangs.

[![A7670E SIMCOM Evaluation Board Supporting LTE CAT1/GNSS/GPS/Bluetooth](https://eicut.com/wp-content/uploads/2025/10/Frame-43_11zon-273x300.webp)](https://eicut.com/product/a7670e-simcom-evaluation-board/)