Xiao ESP32C3 with A7670C to access internet

Can some one please help me with examples on how to use A7670C module with Xiao ESP32C3 for a 4G (internet) connection…!
Purpose is to upload sensor data to cloud. (AWS)
Below is the 4G module I am using.

A7670C GSM 4G Breakout Board

A7670C GSM 4G Breakout Board supports wireless communication modes of GSM/GPRS. It supports maximum 10Mbps downlink rate and 5Mbps uplink rate.

The A7670 series adopts LGA form factor and is compatible with SIM7000/SIM7070 series, and SIM800A.

The A7670 series supports multiple built-in network protocols, supports drivers for main operation systems (USB driver for Windows, Linux and Android etc.) and software function, AT commands are compatible with SIM7500/SIM7600 series modules. Meanwhile the A7670series integrates main industrial standard interfaces, with powerful expansibility, including abundant interfaces such as UART, USB, I2C, GPIO, which is suitable for main.

Hi there,
That is a nice unit, kinda Large but it does ALLOT .

it is Sim800A comparable so any code or examples for that can apply. What is the connection method?
Serial AT commands or as an I2C device.

Having used both the Sim800A and the Sim900A this is a kind of predecessor to those.
Get the data sheet and learn all you can from that, is it 3.3v device? or 5v device? That matters
The Power supply is the single most important item behind any modem but even more so for an LTE network where in the power level is proportional to the connection stability and first HOP range (how far from the first cell tower)

this is info from a Sim900A sheet but the reasoning still applies to this one.

  1. Understanding Power Needs: GSM modules, including the SIM900A, can be sensitive to power supply fluctuations. Their power consumption varies based on network signal strength and the operations they are performing (like sending an SMS or making a call).
  2. SIM900A Specifications: According to its datasheet, the SIM900A module operates efficiently on a 12V, 2A power supply. This specification is critical for the module’s performance and longevity.
  3. Why Correct Voltage and Current are Important:
  • Stability: GSM modules transmit and receive data, which requires bursts of power, especially in areas with poor network reception. An inadequate power supply can lead to module instability or failure to perform tasks.
  • Safety: Using the wrong power specifications not only risks the module’s functionality but also can damage the module or connected components.

What is AT Commands.

AT Commands, short for Attention Commands, are a set of instructions used to control modems. Originating in the early days of computer telecommunications, these commands provide a standard language for modems and other communication devices to interpret and execute commands. Here’s a general overview:

1.History: AT Commands were initially developed for the Hayes Smartmodem 300 in the early 1980s. They have since become a standard for controlling modems.

2.Syntax: The commands typically start with the prefix “AT” (which stands for Attention) to get the modem’s attention. Following this prefix are various commands that instruct the modem what to do. For example, “ATD” followed by a phone number would instruct the modem to dial that number.

Types of Commands:

  • Basic Commands: These are general commands, such as “ATD” for dial, “ATA” for answer, and “ATH” for hang up.
  • Extended Commands: These are more specific and can control various modem parameters or return information about the modem’s status.
  • Manufacturer-Specific Commands: Different modem manufacturers may implement additional custom commands for advanced features specific to their products.

4.Uses: While originally designed for dial-up modems, AT commands have found uses in a variety of other telecommunications devices. For instance, they are widely used in GSM and GPRS modems and devices for sending SMS messages, making calls, or accessing internet services.

5.Execution: The commands can be executed via a serial interface (RS-232), over a network, or even within a system (like a computer or a mobile device) depending on the device and its capabilities.

6**.Modern Relevance:** Even though dial-up modems have largely become obsolete with the advent of broadband internet, AT commands are still relevant in areas like IoT (Internet of Things), where they are used to control and configure GSM/GPRS modules and other telecommunication devices.

GL :slight_smile: PJ

1 Like

Thanks for the details.
I am planning to use SERIAL AT.
It operates on 5V.
Earlier, I used AT commands on Sim800L. But for some reason, the script is not working with this.
I presume, AT commands remain the same for any module.
Hence I posted for support here.

Hi there,
Be sure to use a level shifter between the two devices then.
They are not 100 % identical but close, most of the basic commands will work, but special stuff has different command lines.
GL :slight_smile: PJ