Usage Examples for AT Command Debugging

Hardware Preparation

• DFR0181 Arduino UNO x1
• TEL0097 SIM808 Expansion Shield x1
• External Power Supply x1
• SIM Card x1

Software Preparation

• Download and install the Arduino IDE: Click to download Arduino IDE

• Serial debugging assistant (In this section, we are using DF Serial Debugger)

Steps

1. Plug your SIM card on the SIM808 expansion shield and plug the expansion shield on Arduino UNO, meanwhile don't forget to connect an external power source.
2. Dial the function switch to None, download a sample code Blink to make sure the serial port is not occupied.
3. Press the Boot power button and wait for the SIM card registering a network properly, the Net indicator led flashes slowly (3s once).
4. Slide the function switch to USB_DBG, then we can communicate directly with SIM808 chip through the serial port assistant.

AT Command Examples

Make a Phone Call

Send AT in the serial port assistant, if it returns OK, it means that serial communication has been established. Follow the Figure, enter AT commands, you should get the same content.

Answer the Phone and Hang Up

Send SMS

Read SMS

TCP Communication

GPS Orientation

Note: The GPS antenna must be placed outside before it can obtain a stable GPS location data output.

Send AT + CGSN PWR = 1 command (Open the GPS power)

Send AT + CGNSTST = 1 command (Receive GPS data from the serial port)

If the GPS antenna has been placed outside, you should get the right data soon.

When you want to pause GPS data output, you can sent **AT+CGNSTST=0** command to pause GPS data output.

When you want to turn off GPS function, you can send AT + CGNSPWR = 0 command to turn off the GPS power. Send AT + CPOWD = 1 to shut down the SIM808 chip.

Minimum Functionality Mode (Low Power Consumption)

• AT+CFUN= =0,1,4
  1. AT + CFUN = 0: Minimum functionality mode. In this mode, you can still continue to use the serial port, but the AT command with RF and SIM card features will be disable.
  2. AT + CFUN = 1: Full-function mode (default).
  3. AT + CFUN = 4: Airplane mode. In this mode, you can still continue to use the serial port, but the AT command with RF and SIM card features will be disable.

More features please refer to AT commands