Error Code Reference

The AT command set uses a two-layer error scheme. The outer layer (at_cmd_err_t, defined in openair/lib/at_cmd/at_cmd.h) indicates how the AT framework processed the command. The inner layer (at_cmd_app_err_t, defined in openair/subsys/at_cmd_set/at_cmd_set.h) carries domain-specific detail when the outer code is AT_CMD_ERR_SPECIFIC_ERR (0x80).

Error Response Format

Generic errors:

ERR:<code> — decimal value of at_cmd_err_t (1–7).

Specific errors:

+<CMD>:<hex_app_err> on one line, then ERR on the next.

# Generic — wrong argument count
AT+BLEADVENABLE=
ERR:2

# Specific — advertising set already enabled
AT+BLEADVENABLE=0,ON
+BLEADVENABLE:11
ERR

Framework Error Codes (at_cmd_err_t)

Defined in openair/lib/at_cmd/at_cmd.h.

Code	Constant	Description
0	AT_CMD_ERR_NO_ERROR	No error; command executed successfully (OK response).
1	AT_CMD_ERR_NOT_SUPPORT	Command not supported — Kconfig symbol disabled or operation not implemented.
2	AT_CMD_ERR_WRONG_ARGU_CNT	Wrong number of arguments supplied.
3	AT_CMD_ERR_WRONG_ARGU_RANGE	One or more argument values are outside the permitted range.
4	AT_CMD_ERR_WRONG_ARGU_TYPE	An argument has an unexpected type.
5	AT_CMD_ERR_WRONG_ARGU_TYPE_OR_RANGE	An argument has the wrong type or is out of range.
6	AT_CMD_ERR_WRONG_ARGU_CONTENT	Argument content is syntactically valid but semantically rejected.
7	AT_CMD_ERR_WRONG_EXECUTE_TYPE	The command form used (test / query / execute) is not supported.
0x80	AT_CMD_ERR_SPECIFIC_ERR	Command-specific error; the +<CMD>:<hex_app_err> prefix carries the at_cmd_app_err_t value described in the next section.

Application Error Codes (at_cmd_app_err_t)

Defined in openair/subsys/at_cmd_set/at_cmd_set.h. These values appear in the +<CMD>:<hex_app_err> response line that precedes ERR whenever the framework code is AT_CMD_ERR_SPECIFIC_ERR.

Value ranges

Range	Domain
0x00	No error
0x01–0x05	GAP — role / identity-address errors (legacy, wire-compatible)
0x10–0x1F	Advertising
0x20–0x2F	Context
0x30–0x3F	Parameter validation
0x40–0x4F	BLE / Zephyr errno mapping
0x50–0x5F	GPIO / FIO
0x60–0x6F	System
0x70–0x7F	GATT / ATT
0x80–0x8F	Dynamic GATT staging

Code table

Code	Constant	Description
0x00	AT_ERR_NONE	No error.
0x01	AT_ERR_GAP_ROLE_INITIALIZED	GAP role is already initialised; cannot re-initialise.
0x02	AT_ERR_GAP_ROLE_NOT_SUPPORTED	Requested GAP role is not supported by this build.
0x03	AT_ERR_GAP_SET_BEFORE_INIT	Parameter must be configured before bt_enable().
0x04	AT_ERR_GAP_SET_AFTER_INIT	Parameter must be configured after bt_enable().
0x05	AT_ERR_GAP_ONLY_STATIC_RND_ADDR	Only static random addresses are supported.
0x10	AT_ERR_ADV_INVALID_INDEX	Advertising set index is out of range (≥ AT_CMD_ADV_MAX_INST).
0x11	AT_ERR_ADV_ALREADY_ENABLED	Advertising is already active on the specified set.
0x12	AT_ERR_ADV_NOT_ENABLED	Advertising is not currently active on the specified set.
0x13	AT_ERR_ADV_SET_NOT_CREATED	Extended advertising set has not been created yet.
0x14	AT_ERR_ADV_INVALID_PARAM	One or more advertising parameters are invalid.
0x15	AT_ERR_ADV_DATA_TOO_LONG	Advertisement payload exceeds AT_CMD_MAX_ADV_DATA_LEN.
0x16	AT_ERR_ADV_SCAN_DATA_TOO_LONG	Scan-response payload exceeds AT_CMD_MAX_ADV_DATA_LEN.
0x20	AT_ERR_CTX_NULL	AT command context pointer is NULL.
0x21	AT_ERR_CTX_NOT_INITIALIZED	AT command context has not been initialised.
0x30	AT_ERR_PARAM_INVALID	Parameter value is invalid for this operation.
0x31	AT_ERR_PARAM_OUT_OF_RANGE	Parameter value is outside the accepted range.
0x32	AT_ERR_PARAM_INVALID_LENGTH	Parameter length is invalid (too short or too long).
0x40	AT_ERR_BLE_EINVAL	Maps EINVAL — invalid argument passed to a BLE/Zephyr API.
0x41	AT_ERR_BLE_EBUSY	Maps EBUSY — BLE device or resource is busy.
0x42	AT_ERR_BLE_ENOMEM	Maps ENOMEM — out of memory in the BLE stack.
0x43	AT_ERR_BLE_ENOTSUP	Maps ENOTSUP — operation not supported by the BLE stack.
0x44	AT_ERR_BLE_EACCES	Maps EACCES — permission denied (e.g. insufficient security).
0x45	AT_ERR_BLE_ENODEV	Maps ENODEV — BLE device not found or not ready.
0x46	AT_ERR_BLE_ETIMEDOUT	Maps ETIMEDOUT — BLE operation timed out.
0x47	AT_ERR_BLE_ECONNREFUSED	Maps ECONNREFUSED — connection request was refused.
0x48	AT_ERR_BLE_ECONNRESET	Maps ECONNRESET — connection was reset by the remote peer.
0x49	AT_ERR_BLE_EPIPE	Maps EPIPE — broken pipe / write on a closed connection.
0x4A	AT_ERR_BLE_EALREADY	Maps EALREADY — operation already in progress, or address already set.
0x4F	AT_ERR_BLE_UNKNOWN	Unrecognised BLE/Zephyr errno (catch-all).
0x50	AT_ERR_GPIO_NOT_READY	GPIO device (gpio0) is not ready. Used by SYSFUNCPIN and SYSPM.
0x51	AT_ERR_GPIO_CONFIG	gpio_pin_configure() or gpio_pin_interrupt_configure() failed. Used by SYSFUNCPIN and SYSPM.
0x60	AT_ERR_SYS_NEED_REBOOT	A reboot is required for the requested setting to take effect.
0x61	AT_ERR_SYS_NOT_READY	System subsystem is not ready.
0x62	AT_ERR_SYS_UART_NOT_READY	Console UART device is not ready. Used by SYSUARTBR and SYSUARTFC.
0x63	AT_ERR_SYS_UART_CONFIG	uart_configure() or uart_config_get() failed. Used by SYSUARTFC.
0x70	AT_ERR_GATT_INVALID_HANDLE	GATT attribute handle is invalid or out of range.
0x71	AT_ERR_GATT_READ_NOT_PERMITTED	Read operation is not permitted on this attribute.
0x72	AT_ERR_GATT_WRITE_NOT_PERMITTED	Write operation is not permitted on this attribute.
0x73	AT_ERR_GATT_INVALID_PDU	Received GATT PDU is invalid.
0x74	AT_ERR_GATT_INSUFF_AUTHEN	Insufficient authentication to access this attribute.
0x75	AT_ERR_GATT_REQUEST_NOT_SUPPORTED	GATT request opcode is not supported.
0x76	AT_ERR_GATT_INVALID_OFFSET	Attribute value offset is beyond the end of the value.
0x77	AT_ERR_GATT_INSUFF_AUTHOR	Insufficient authorization to access this attribute.
0x78	AT_ERR_GATT_PREPARE_QUEUE_FULL	Prepare-write queue is full.
0x79	AT_ERR_GATT_ATTRIBUTE_NOT_FOUND	No attribute found within the handle range.
0x7A	AT_ERR_GATT_ATTRIBUTE_NOT_LONG	Attribute is not a long attribute; long read/write not applicable.
0x7B	AT_ERR_GATT_INSUFF_ENC_KEY_SIZE	Encryption key size is insufficient for this attribute.
0x7C	AT_ERR_GATT_INVALID_ATTR_VAL_LEN	Attribute value length is invalid for a write operation.
0x7D	AT_ERR_GATT_UNLIKELY	Unlikely GATT error (catch-all for unexpected ATT errors).
0x7E	AT_ERR_GATT_INSUFF_ENC	Insufficient encryption level for this attribute.
0x7F	AT_ERR_GATT_UNSUPPORTED_GRP_TYPE	Attribute group type is not supported.
0x80	AT_ERR_GATT_DYN_SVC_ACTIVE	Service is already active; characteristics/descriptors cannot be added. Used by BLEGATTADDCHAR and BLEGATTADDDESC.
0x83	AT_ERR_GATT_DYN_NO_SVC	No BLEGATTADDSERVICE has been issued, or all staged services are already active. Returned by BLEGATTADDCHAR.
0x84	AT_ERR_GATT_DYN_NO_CHAR	No BLEGATTADDCHAR has been issued before BLEGATTADDDESC.

BLE / Zephyr Errno Mapping

When a BLE or Zephyr API returns a standard errno, at_cmd_map_errno() (defined in at_cmd_set_common.h) translates it to the corresponding AT_ERR_BLE_* application error code automatically.

Zephyr errno	App error code	Meaning
EINVAL	AT_ERR_BLE_EINVAL (0x40)	Invalid argument
EBUSY	AT_ERR_BLE_EBUSY (0x41)	Device or resource busy
ENOMEM	AT_ERR_BLE_ENOMEM (0x42)	Out of memory
ENOTSUP	AT_ERR_BLE_ENOTSUP (0x43)	Operation not supported
EACCES	AT_ERR_BLE_EACCES (0x44)	Permission denied
ENODEV	AT_ERR_BLE_ENODEV (0x45)	No such device
ETIMEDOUT	AT_ERR_BLE_ETIMEDOUT (0x46)	Operation timed out
ECONNREFUSED	AT_ERR_BLE_ECONNREFUSED (0x47)	Connection refused
ECONNRESET	AT_ERR_BLE_ECONNRESET (0x48)	Connection reset by peer
EPIPE	AT_ERR_BLE_EPIPE (0x49)	Broken pipe
EALREADY	AT_ERR_BLE_EALREADY (0x4A)	Already in progress / address already set
(other)	AT_ERR_BLE_UNKNOWN (0x4F)	Unrecognised errno value

Tag Error Codes (at_cmd_tag_err_t)

Defined in openair/subsys/at_cmd_set/at_cmd_tag.h. These codes are used exclusively by tag command callbacks (CONFIG_AT_CMD_TAG_SET) and are reported directly in the +<CMD>:<hex_code> specific-error response.

Code	Constant	Description
0	AT_CMD_TAG_NO_ERR	Operation completed successfully.
1	AT_CMD_TAG_ERR_INVALID_PARAM	Invalid parameter (e.g. NULL pointer passed to callback).
2	AT_CMD_TAG_ERR_NOT_ALLOWED	Operation not allowed in the current tag state.
3	AT_CMD_TAG_ERR_INTERNAL	Internal or platform-level error.
4	AT_CMD_TAG_ERR_BLE_INIT	BLE stack initialisation failed.
5	AT_CMD_TAG_ERR_MOTION_SENSOR	Motion sensor error.
6	AT_CMD_TAG_ERR_BUTTON	Button configuration error.
7	AT_CMD_TAG_ERR_WDOG	Watchdog configuration error.
8	AT_CMD_TAG_ERR_BUZZER	Buzzer configuration error.