Custom AT Development Guide_Rev1.2

Revision History

Version	Date	Author	Reviewer	Revision Content
Rev1.0	2023-09-11	lxh	zlc	Initial document creation
Rev1.1	2024-03-25	sxx		Changed document name
Rev1.2	2024-10-25	LJZ		Modified document format

1 Introduction

This document introduces how to add custom AT command functionality in LTE-EC71X OpenCPU.

2 API Function Overview

Function	Description
`liot_open_atcmd_init()`	This function is used to enable AT function.
`liot_atcmd_register()`	This function is used to register AT table.
`liot_atcmd_reply()`	This interface is the AT response function.

3 Type Descriptions

3.1 liot_atCmdType_t

AT command types.

Declaration

typedef enum
{
    LIOT_AT_CMD_SET  = NA | EQ | AR,
    LIOT_AT_CMD_TEST = NA | EQ | QU,
    LIOT_AT_CMD_READ = NA | QU,
    LIOT_AT_CMD_EXE  = NA
} liot_atCmdType_t;

Parameters

LIOT_AT_CMD_SET: AT command setting.
LIOT_AT_CMD_TEST: AT command test.
LIOT_AT_CMD_READ: AT command read.
LIOT_AT_CMD_EXE: AT command execution.

The following text

3.2 liot_atcmd_basic_type_e

AT command basic index types:

Declaration

typedef enum
{
    LIOT_AT_BASIC_N_C_IDX = 0,
    LIOT_AT_BASIC_N_D_IDX,
    LIOT_AT_BASIC_N_E_IDX,
    LIOT_AT_BASIC_N_F_IDX,
    LIOT_AT_BASIC_N_S_IDX,
    LIOT_AT_BASIC_N_V_IDX,
    LIOT_AT_BASIC_N_W_IDX,
    LIOT_AT_BASIC_E_IDX,
    LIOT_AT_BASIC_I_IDX,
    LIOT_AT_BASIC_L_IDX,
    LIOT_AT_BASIC_M_IDX,
    LIOT_AT_BASIC_Q_IDX,
    LIOT_AT_BASIC_V_IDX,
    LIOT_AT_BASIC_X_IDX,
    LIOT_AT_BASIC_Z_IDX,
    LIOT_AT_BASIC_T_IDX,
    LIOT_AT_BASIC_P_IDX,
} liot_atcmd_basic_type_e;

3.3 liot_at_result_enum_type

AT command return types:

Declaration

typedef enum
{
    LIOT_AT_NO_RSP     = -1,
    LIOT_AT_OK         = 0,
    LIOT_AT_CONNECT    = 1,
    LIOT_AT_RING       = 2,
    LIOT_AT_NO_CARRIER = 3,
    LIOT_AT_ERROR      = 4,

    LIOT_AT_CME_ERROR = 100,
} liot_at_result_enum_type;

Parameters

LIOT_AT_NO_RSP: AT command no response.
LIOT_AT_OK: AT command response successful.
LIOT_AT_CONNECT: AT command continues execution.
LIOT_AT_RING: AT command is executing.
LIOT_AT_ERROR: AT command error.
LIOT_AT_CME_ERROR: AT command execution error.

3.4 liot_atCommand_Input

AT command input parameters:

Declaration

typedef struct liot_atCommand_Input_t
{
    CHAR name[LIOT_AT_CMD_NAME_MAX_LEN + 1];
    UINT8 op;
    liot_atHandle atHandle;
    UINT8 args_count;
    CHAR *arg[LIOT_AT_CMD_MAX_ARG];
} liot_atCommand_Input;

Parameters

Type	Parameter	Description
CHAR	name	AT command name
UINT8	op	AT command execution type, refer to 4.1
liot_atHandle	atHandle	AT execution handle
UINT8	args_count	Number of parameters
CHAR *	arg	Command parameter content

3.5 liot_atCommand

AT command format declaration definition:

Declaration

typedef struct liot_atCommand_t
{
    const CHAR *pName;
    liot_at_result_enum_type (*atProcFunc)(const liot_atCommand_Input *pAtInputCtx);
} liot_atCommand, *liot_atCommandP;

Parameters

Type	Parameter	Description
const CHAR*	pName	AT command name
liot_at_result_enum_type	atProcFunc	AT function name

3.6 liot_atMsgId_e

AT command message ID type enumeration is defined as follows:

Declaration

typedef enum
{
    LIOT_AT_MIN_MSG = 0,

    LIOT_AT_URC_MSG,
    LIOT_AT_SIO_MSG,

    LIOT_AT_SIM_MSG,

    LIOT_AT_FILE_MSG,

    LIOT_AT_SOCKET_MSG,
    LIOT_AT_NTP_MSG,
    LIOT_AT_PING_MSG,
    LIOT_AT_HTTP_MSG,
    LIOT_AT_CTCC_SREG_MSG,
    LIOT_AT_FTP_MSG,
    LIOT_AT_MQTT_MSG,
    LIOT_AT_LBS_MSG,
    LIOT_AT_LWM2M_MSG,
    LIOT_AT_CMCC_DM_MSG,
    LIOT_AT_CTWING_MSG,
    LIOT_AT_PDP_MSG,
    LIOT_AT_DNS_MSG,
    LIOT_AT_MAX_MSG
} liot_atMsgId_e;

Parameters

LIOT_AT_MIN_MSG: Minimum message ID.
LIOT_AT_URC_MSG: AT command URC message ID.
LIOT_AT_SIO_MSG: IO message ID.
LIOT_AT_SIM_MSG: SIM card message ID.
LIOT_AT_FILE_MSG: File system message ID.
LIOT_AT_SOCKET_MSG: Socket message ID.
LIOT_AT_NTP_MSG: NTP message ID.
LIOT_AT_PING_MSG: PING message ID.
LIOT_AT_CTCC_SREG_MSG: Telecom self-registration message ID.
LIOT_AT_FTP_MSG: FTP message ID.
LIOT_AT_HTTP_MSG: HTTP message ID.
LIOT_AT_MQTT_MSG: MQTT message ID.
LIOT_AT_LBS_MSG: LBS message ID.
LIOT_AT_LWM2M_MSG: LWM2M message ID.
LIOT_AT_CMCC_DM_MSG: Mobile self-registration message ID.
LIOT_AT_CTWING_MSG: CTWING message ID.
LIOT_AT_PDP_MSG: PDP message ID.
LIOT_AT_DNS_MSG: DNS message ID.
LIOT_AT_MAX_MSG: Maximum message ID.

4 API Function Details

4.1 liot_atcmd_reply

This function is used to return the result after AT command execution, returning the result and error code to the serial port.

Declaration

int liot_atcmd_reply(liot_atHandle atHandle, liot_at_result_enum_type result_code, const CHAR *resp_str);

Parameters

liot_atHandle: [In] AT command handle.
result_code: [In] AT command execution result code.
resp_str: [In] Return string information.

Return Value

int: Execution result code, see 4.2 for reference.

4.2 liot_open_atcmd_init

This function is used to initialize and enable AT command table.

Declaration

void liot_open_atcmd_init(void)

Parameters

void.

Return Value

void.

4.3 liot_atcmd_register

This function is used to register AT command table.

Declaration

void liot_atcmd_register(const liot_atCommandP tab_ptr, const UINT32 tab_size);

Parameters

tab_ptr: [In] AT command table address.
tab_size: [In] AT command table size.

Return Value

void.

Requirements

5 Code Example

Refer to examples/demo/src/demo_atcmd.c for sample code. The following execution result indicates that all information was obtained normally:

Other issues