What are AT Commands? AT Commands 2025 Guide

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What are AT commands for?

AT commands are used to communicate with and control modems. They allow users to set parameters, control the modem's operation, and execute specific tasks like:

Read/send SMS and USSD
Send TCP/IP data
Get hardware and SIM information (IMEI, IMSI, etc.)
Waking the device or putting it into sleep mode
Power-saving mode configurations
Scanning and registering to available networks
Collecting updates on network conditions
Answering phone calls and more

What is the AT command messages?

The AT command list of messages varies depending on the modem and manufacturer. Generally, it commands for dialing, hanging up, sending SMS, setting modem parameters, and querying device information. There are several AT commands related to managing messages on a cellular modem, like

AT+CMGL - List Messages
AT+CMGL=ALL - Lists all messages
AT+CMGL=n - Lists message with index "n"
AT+CMGL=REC READ - Lists only received and read messages
AT+CMGL=REC UNREAD - Lists only received and unread messages
AT+CMGR - Read Message
AT+CMGS - Send Message
AT+CMGD - Delete Message

What are 3GPP AT commands for?

3GPP AT commands are used to control 3G and 4G cellular modems in accordance with the 3rd Generation Partnership Project (3GPP) standards. They manage network registration, data connection, SMS, and other network-related functions, providing extensive control over modem operations.

How do you send multiple commands?

There are two main ways to send multiple AT commands:

1. Sending commands sequentially:This is the most common approach and involves sending each command one after the other, followed by a newline character (usually represented by \r or \r\n).

2. Combining commands in a single line (limited compatibility): Some devices might allow chaining multiple AT commands in a single line separated by semicolons (;).

What is the use of AT commands GSM?

In GSM (Global System for Mobile Communications), AT commands interact with GSM modems. They control various functions, such as making calls, sending texts, and setting network parameters.

What is the AT command GPRS?

The AT command for GPRS (General Packet Radio Service) typically involves commands for setting up the Network Registration, PDP Context Management for bearer profile (e.g., AT+CGDCONT), and activating or deactivating the data service (e.g., AT+CGACT).

What is the AT command in Bluetooth?

AT commands in Bluetooth modems enable functions like device pairing, initiating or terminating connections, and setting device discoverability and naming.