System Commands

See AT Command Format for command syntax.

AT+SYSFUNCPIN — GPIO Function Pin Control

Kconfig:: CONFIG_AT_CMD_SYSFUNCPIN
Depends:: CONFIG_GPIO
Execute:: AT+SYSFUNCPIN=<io>,<direction>,<signal>
Query:: AT+SYSFUNCPIN?
Response:: +SYSFUNCPIN:<io>,<direction>,<signal>
Event:: +EVTSYSFUNCPIN:<io>,<reason> — emitted when an input interrupt fires

Configures a GPIO pin (on gpio0) as a driven output or a monitored input with interrupt-based event notification.

Parameter	Range	Description
`io`	0–255	GPIO pin number on `gpio0`.
`direction`	0–1	`0` = input, `1` = output.
`signal`	0–4	For output: `0` = drive low, `1` = drive high. For input: `0` = interrupt on level-low, `1` = level-high, `2` = rising edge, `3` = falling edge, `4` = pull-up (no interrupt).

Note

signal=4 (pull-up) is input only. Combining direction=1 with signal=4 is rejected with ERR.

Note

When an input interrupt fires, a +EVTSYSFUNCPIN:<io>,<reason> unsolicited event is emitted asynchronously. The interrupt is automatically disabled after firing; re-issue the execute command to re-arm it.

Note

The <reason> field in +EVTSYSFUNCPIN carries the trigger cause as defined by at_cmd_sysfuncpin_reason_t in at_cmd_set.h:

Value	Meaning
`4`	`AT_SYSFUNCPIN_REASON_INTR` — GPIO interrupt fired.

AT+SYSFUNCPIN=10,1,0
OK
AT+SYSFUNCPIN=10,1,1
OK
AT+SYSFUNCPIN=9,0,2
OK
# <rising edge on P9 fires>
+EVTSYSFUNCPIN:9,4
AT+SYSFUNCPIN?
+SYSFUNCPIN:9,0,2
OK

AT+SYSPM — System Power Mode

Kconfig:: CONFIG_AT_CMD_SYSPM
Depends:: CONFIG_PM, CONFIG_GPIO
Execute:: AT+SYSPM=<mode>,<io>,<wakeup_level>
Query:: AT+SYSPM?
Response:: +SYSPM:<mode>,<io>,<wakeup_level>

Enters the device into a low-power state. Currently only hibernation (mode=1) is supported. The device does not return from this call — it resets on wakeup via the specified GPIO pin.

Parameter	Range	Description
`mode`	1	Power mode. `1` = hibernation (only value currently accepted).
`io`	0–255	GPIO pin number (on `gpio0`) used as the wakeup source.
`wakeup_level`	0–1	`0` = wake on level-low, `1` = wake on level-high.

Warning

AT+SYSPM=1,... places the device into deep hibernation immediately after returning OK. The firmware does not resume from the point of the call — the device performs a cold reset on wakeup. Do not issue this command during automated testing unless hardware recovery is available.

AT+SYSPM=1,5,1
OK
# <device hibernates; press Button0 / P5 HIGH to wake>
# <device cold-resets on wakeup>

AT+SYSUARTBR — UART Baud Rate

Kconfig:: CONFIG_AT_CMD_SYSUARTBR
Depends:: CONFIG_UART_USE_RUNTIME_CONFIGURE
Execute:: AT+SYSUARTBR=<baud_rate>,<defer_apply_cs>
Query:: AT+SYSUARTBR?
Response:: +SYSUARTBR:<baud_rate>

Changes the baud rate of the console UART at runtime. OK is sent at the current baud rate before the change is applied, giving the host time to switch its serial port within the defer window.

Parameter	Type	Description
`baud_rate`	decimal	New baud rate. Must be one of: `19200`, `38400`, `57600`, `115200`, `230400`, `460800`. Any other value returns `ERR`.
`defer_apply_cs`	1–255	Delay before the baud rate is applied, in centiseconds (1 cs = 10 ms). The host must switch its own serial port to the new baud rate within this window.

Note

Query returns the currently active baud rate, not the pending one. On power-up, the baud rate is read from the hardware UART configuration; if unavailable, it defaults to 115200.

AT+SYSUARTBR=115200,10
OK
# <switch host serial port to 115200 within 100 ms>

AT+SYSUARTFC — UART Flow Control

Kconfig:: CONFIG_AT_CMD_SYSUARTFC
Depends:: CONFIG_UART_USE_RUNTIME_CONFIGURE
Execute:: AT+SYSUARTFC=<action>
Query:: AT+SYSUARTFC?
Response:: +SYSUARTFC:<action>

Enables or disables RTS/CTS hardware flow control on the console UART at runtime.

Parameter	Range	Description
`action`	0–1	`0` = disable flow control (`UART_CFG_FLOW_CTRL_NONE`), `1` = enable RTS/CTS (`UART_CFG_FLOW_CTRL_RTS_CTS`).

Warning

Enabling RTS/CTS (action=1) requires the CTS and RTS lines to be physically wired on the board. Sending AT+SYSUARTFC=1 on a board without those lines connected will stall UART TX indefinitely.

AT+SYSUARTFC=0
OK
AT+SYSUARTFC?
+SYSUARTFC:0
OK

System Command Error Codes

The following application error codes (returned in the ERR response payload) are defined in at_cmd_set.h and may be returned by the system commands above.

Code	Constant	Description
`0x81`	`AT_CMD_ERR_LOCKED`	AT command channel is locked. Returned by any configuration command while locked. Use `AT+SYSUNLOCK` to unlock.
`0x90`	`AT_ERR_ACCESS_INVALID_KEY`	Wrong unlock key supplied to `AT+SYSUNLOCK`.
`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`.
`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`.

AT+SYSBDADDR — Bluetooth Device Address

Kconfig:: CONFIG_AT_CMD_SYSBDADDR
Execute:: AT+SYSBDADDR=<bt_id>,<addr(6B)> — bt_id range: 1 to CONFIG_BT_ID_MAX − 1
Query:: AT+SYSBDADDR?
Response:: +SYSBDADDR:<bt_id0>,<addr0>,<bt_id1>,<addr1>,... (all identities in one response)

Sets the random static identity address for a non-default BT identity. Query returns all configured identities.

Note

bt_id = 0 (default identity) is not supported for execute — returns ERR. Valid range is 1 to CONFIG_BT_ID_MAX − 1. Requires CONFIG_BT_ID_MAX > 1.

Note

<addr> must be a valid random static identity address. Non-identity addresses are rejected with ERR.

Note

Cannot be set (execute) while advertising is active for the given bt_id or while any connection is active — returns ERR. Query is always allowed.

AT+SYSBDADDR=1,C21122334455
OK
AT+SYSBDADDR?
+SYSBDADDR:0,FFFFFFFFFFFF,1,C21122334455
OK

AT+SYSRESET — System Reset

Kconfig:: CONFIG_AT_CMD_SYSRESET
Execute:: AT+SYSRESET=<type> — 0 = warm, 1 = cold
Query:: not supported

AT+SYSRESET=0
OK

AT+SYSLOCK — Channel Lock

Kconfig:: CONFIG_AT_CMD_LOCK_SET
Execute:: AT+SYSLOCK=ON — lock the AT command channel
Query:: AT+SYSLOCK?
Response:: +SYSLOCK:ON / +SYSLOCK:OFF

Locks the AT command channel or queries the current lock state. This command is lock-exempt and can be executed at any time regardless of lock state.

While locked, all configuration commands return ERROR:129 (AT_CMD_ERR_LOCKED = 0x81). The channel starts locked on every power-on and every new BLE connection.

Lock state lifecycle:

Device powers on or resets → starts locked
New BLE connection established → automatically re-locked
AT+SYSUNLOCK=<key> with correct key → unlocked
Configuration commands can now be issued
BLE disconnect or device reset → automatically re-locked

AT+SYSLOCK=ON
OK
AT+SYSLOCK?
+SYSLOCK:ON
OK

AT+SYSUNLOCK — Channel Unlock

Kconfig:: CONFIG_AT_CMD_LOCK_SET
Execute:: AT+SYSUNLOCK=<key>
Query:: not supported

Unlocks the AT command channel by verifying the provided key. Must be sent before any configuration command. This command is lock-exempt.

Parameter	Type	Description
`key`	string	Unlock key (max 32 chars). Configured at compile time via `CONFIG_AT_CMD_SYSUNLOCKKEY_VALUE`.

Responses:

OK — Channel unlocked
ERROR:144 — Wrong key (AT_ERR_ACCESS_INVALID_KEY = 0x90)

Note

The channel is automatically re-locked on each new BLE connection and on device reset. AT+SYSLOCK and AT+SYSUNLOCK are always permitted regardless of the current lock state.

AT+SYSUNLOCK=atm1atm123
OK

AT+SYSSTORAGE — NVS Key-Value Storage

Kconfig:: CONFIG_AT_CMD_SYSSTORAGE
Depends:: CONFIG_SETTINGS (application must provide a settings backend)
Execute:: AT+SYSSTORAGE=<GET|SAVE|DEL>,<key>,<value>
Query:: AT+SYSSTORAGE?
Response:: +SYSSTORAGE:<READY|NOT_READY> (query); +SYSSTORAGE:<key>,<value> (GET)

Query reports whether the settings backend is ready. Execute returns ERR if the backend is not ready — use the query to check readiness before issuing GET/SAVE/DEL.

AT+SYSSTORAGE?
+SYSSTORAGE:READY
OK
AT+SYSSTORAGE=SAVE,mykey,hello
OK
AT+SYSSTORAGE=GET,mykey,
+SYSSTORAGE:mykey,hello
OK
AT+SYSSTORAGE=DEL,mykey,
OK

AT+SYSUARTRAW — Bounded UART/BLE Raw Data Transfer

Kconfig:: CONFIG_AT_CMD_SYSUARTRAW
Depends:: CONFIG_BT_GATT_DYNAMIC_DB, active BLE connection
Execute:: AT+SYSUARTRAW=<conn_idx>,<att_idx>,<direction>,<length>
Query:: AT+SYSUARTRAW?
Response:: +SYSUARTRAW:<conn_idx>,<att_idx>,<direction>,<length>

Initiates a single-shot bounded raw data transfer between the UART channel and a connected BLE peer. The system leaves AT command mode for exactly <length> bytes, then automatically returns to AT command mode.

A built-in GATT service (UUID 9E940001-E8D4-4AB3-8A03-F012DFD53BA0) is dynamically registered on execute and unregistered when the transfer completes.

Parameters

Parameter	Type	Description
`conn_idx`	decimal	BLE connection index (0 to `CONFIG_BT_MAX_CONN` − 1). Returns `ERR` if no active connection exists at this index.
`att_idx`	decimal	GATT attribute index within the built-in bridge service used as the data endpoint (write target / notify source).
`direction`	decimal	`0` = Host → Atmosic: UART bytes are collected and forwarded to the BLE peer via GATT notifications (UART→BLE). `1` = Atmosic → Host: data written by the BLE peer to the data characteristic is forwarded out on the UART (BLE→UART).
`length`	decimal	Number of bytes to transfer before automatically returning to AT mode.

Direction 0 — UART → BLE

After OK, the UART channel captures raw bytes instead of AT commands. Each byte (or batch, up to ATT MTU − 3) is forwarded to the BLE peer via GATT notification. The peer must have subscribed to notifications on the data characteristic (CCCD enabled) before data is sent; bytes received while the peer is not subscribed are discarded. After exactly <length> bytes have been sent, the system unregisters the GATT service and returns to AT mode.

Direction 1 — BLE → UART

After OK, the AT command parser remains active on the UART. Data written by the BLE peer to the GATT data characteristic is forwarded byte-for-byte to the UART output. After exactly <length> bytes have been received from the peer, the GATT service is unregistered and the transfer is complete.

Note

A valid active BLE connection at conn_idx is required. The command returns ERR immediately if no connection exists at that index.

Note

For direction 0, the BLE peer must enable notifications on the data characteristic (CCCD) before the transfer begins, or UART bytes will be dropped.

Note

ISR integration required for direction 0. The UART driver’s interrupt service routine must forward received bytes into the raw bridge. Two public APIs are provided in at_cmd_set.h (guarded by CONFIG_AT_CMD_SYSUARTRAW):

bool at_cmd_sysuartraw_is_active(void) — returns true while a direction-0 transfer is in progress. Poll this in the UART RX ISR.
void at_cmd_sysuartraw_rx_byte(uint8_t byte) — enqueues the byte into the internal ring buffer and schedules BLE notification via the system work queue. Call only when at_cmd_sysuartraw_is_active() is true.

Without this hook, UART bytes are processed by the AT command parser instead of being forwarded over BLE.

# Direction 0: send 12 bytes from UART to BLE peer
AT+SYSUARTRAW=0,0,0,12
OK
# <host sends 12 raw bytes on UART>
# <system automatically returns to AT mode after 12 bytes>

# Direction 1: receive 8 bytes from BLE peer to UART
AT+SYSUARTRAW=0,0,1,8
OK
# <BLE peer writes 8 bytes to the data characteristic>
# <bytes appear on UART; system returns to AT mode after 8 bytes>

# Query current transfer state
AT+SYSUARTRAW?
+SYSUARTRAW:0,0,0,12
OK