AT Command Handbook-V2.0

General AT Commands

1. “AT\r\n”

   Return: AT\r\n OK\r\n
Note: AT instruction test can be started up when detecting the module

2. “ATE0\r\n”

   Return: ATE0\r\n OK\r\n
Note: Close the echo

3. “AT+CNMI=2,1,0,1,0\r\n”

   Return: OK\r\n
Note: Set URC report format of new short message, and this command can be set after SMS ready，i.e., set after SIM800C module is informed of Arduino “SMS ready”,URC reports after receiving the short message, 1 is the serial number of the short message in the storage, +CMTI:" SM",1

4. “AT+CSCS="UCS2"\r\n”

   Return: OK\r\n
Note: Set short message by using UCS2 code

5. “AT+CSQ\r\n”

   Return: +CSQ:<rssi>,<ber> OK\r\n
<rssi>
0 is less than or equal to -115dBm
1 -111dBm
2...30 -110... -54dBm
31 is greater than or equal to -52dBm
99 is unknown or non-measurable
<ber> (percentage)：
RXQUA value in 0...7 table, refer to 7.2.4 of GSM 05.08 [20]
99 is unknown or non-measurable

6. “ATA\r\n”

   Return: OK\r\n
Note: Answer the telephone

7. “ATH0\r\n”

   Return: OK\r\n
Note: Hang up

8. “AT+CLIP=1\r\n”

   Return: OK\r\n
Note: Open the caller ID

9. “ATD15982373181；\r\n”

   Return: OK\r\n
Note: Make a call

10. “AT+DDET=1\r\n”

    Return: OK\r\n
Note: Open DTMF function

11. “AT+CMGS="00310038003600310036003300360036003500340037"\r\n”

    Return: >
Note: Those in the quotation mark are UCS2-BIG codes of phone numbers. Send a short message, after returning the character “>”, input the short message to be sent, with the content code of UCS2 code (set above), then check HEX sending, send “1a”, and end with CTRL+Z(0x1A).

12. “AT+CMGR=1\r\n”

    Return: +CMTI: ........
Note: Read the short message, and return the content of the short message
Description of parameters: “1” is the serial number of the short message stored in SIM800H module

13. “AT+CMGD=1\r\n”

    Return: OK\r\n
Note: Delete the short message with the serial number of 1 in the storage

    Note: For more AT command, please check AT Instruction