Commands and Sequences

LA⁴ accepts lighting instructions as a sequence of CSV rows written to ~/la4_sequence.csv on the node. Each row is a command: the register name followed by its parameters, comma-separated.

Load and execute a sequence using the boardio program in the device with the following commands:

boardiocli uSeq — loads the sequence file into the firmware
boardiocli runSeq — starts execution

All commands return BOARDIO_READY on success or BOARDIO_ERROR on failure which are sent over your listener as message events.

Command reference

MODEL_LIGHT

Controls the constant model light (continuous, non-flash illumination).

Parameter	Values	Min	Max
Power level	Percent %	0 (OFF)	100

Example — turn on the model light at 50% power:

MODEL_LIGHT,50

FOCUS_LIGHT

Controls the constant focus light (continuous illumination with a configurable on-duration, useful for autofocus before a shot).

Parameter	Values	Min	Max
Power level	Percent %	0	100
Focus time	Milliseconds	0	9999

Example — turn on the focus light at 80% power for 500 ms:

FOCUS_LIGHT,80,500

ALL_NIKON

Shoots one picture with all four LED lights. Use with Nikon cameras.

Parameter	Values	Min	Max
Power level	Percent %	0	100

Example — fire all four LEDs at 80% power:

ALL_NIKON,80

OLAT_NIKON

Shoots four pictures, one per LED, firing each in sequence. Use with Nikon cameras.

Parameter	Values	Min	Max
Power level	Percent %	0	100
Drive Mode	0 = Single Frame, 1 = Continuous (use with all continuous modes: High+, High, Mid, etc.)	-	-

Example — shoot one-light-at-a-time at 75% power in continuous mode:

OLAT_NIKON,75,1

N_LIGHTS_NIKON

Shoots one picture with a chosen subset of the four LEDs. Use with Nikon cameras.

Parameter	Values	Min	Max
Power level	Percent %	0	100
LED1	0 = OFF, 1 = ON	-	-
LED2	0 = OFF, 1 = ON	-	-
LED3	0 = OFF, 1 = ON	-	-
LED4	0 = OFF, 1 = ON	-	-

Example — fire LEDs 1 and 3 at 60% power (LEDs 2 and 4 OFF):

N_LIGHTS_NIKON,60,1,0,1,0

ALL_CANON

Shoots one picture with all four LED lights. Use with Canon cameras and when using other camera manufacturers (e.g. Fujifilm, Panasonic).

Parameter	Values	Min	Max
Power level	Percent %	0 (OFF)	100
Shutter speed	Milliseconds	0 (OFF)	109

Example — fire all four LEDs at 80% power with a 105 ms on-duration:

ALL_CANON,80,105

OLAT_CANON

Shoots four pictures, one per LED, firing each in sequence. Use with Canon cameras and when using other camera manufacturers (e.g. Fujifilm, Panasonic).

Parameter	Values	Min	Max
Power level	Percent %	0 (OFF)	100
Drive Mode	0 = Single Frame, 1 = Continuous (use with all continuous modes: High+, High, Mid, etc.)	-	-
Shutter speed	Milliseconds	0 (OFF)	109

Example — shoot one-light-at-a-time at 75% power in continuous mode with a 105 ms on-duration:

OLAT_CANON,75,1,105

N_LIGHTS_CANON

Shoots one picture with a chosen subset of the four LEDs. Use with Canon cameras and when using other camera manufacturers (e.g. Fujifilm, Panasonic).

Parameter	Values	Min	Max
Power level	Percent %	0	100
LED1	0 = OFF, 1 = ON	-	-
LED2	0 = OFF, 1 = ON	-	-
LED3	0 = OFF, 1 = ON	-	-
LED4	0 = OFF, 1 = ON	-	-
Shutter speed	Milliseconds	0 (OFF)	109

Example — fire LEDs 1 and 3 at 60% power with a 105 ms on-duration:

N_LIGHTS_CANON,60,1,0,1,0,105

ALL_SONY

Shoots one picture with all four LED lights. Use with Sony cameras.

Parameter	Values	Min	Max
Power level	Percent %	0	100

Example — fire all four LEDs at 80% power:

ALL_SONY,80

OLAT_SONY

Shoots four pictures, one per LED, firing each in sequence. Use with Sony cameras.

Parameter	Values	Min	Max
Power level	Percent %	0	100
Drive Mode	0 = Single Frame, 1 = Continuous (use with all continuous modes: High+, High, Mid, etc.)	-	-

Example — shoot one-light-at-a-time at 75% power in continuous mode:

OLAT_SONY,75,1

N_LIGHTS_SONY

Shoots one picture with a chosen subset of the four LEDs. Use with Sony cameras.

Parameter	Values	Min	Max
Power level	Percent %	0	100
LED1	0 = OFF, 1 = ON	-	-
LED2	0 = OFF, 1 = ON	-	-
LED3	0 = OFF, 1 = ON	-	-
LED4	0 = OFF, 1 = ON	-	-

Example — fire LEDs 1 and 3 at 60% power (LEDs 2 and 4 OFF):

N_LIGHTS_SONY,60,1,0,1,0

ALL_E

Shoots one picture with all four LED lights using the camera's electronic shutter instead of a physical shutter trigger. Camera-agnostic — use with any camera in electronic shutter mode.

Parameter	Values	Min	Max
Power level	Percent %	0 (OFF)	100
Shutter press duration	Milliseconds — time the shoot button is held down (10 ms is a good start)	0	9999
Shutter lag	Milliseconds — time from button release until the shutter curtain opens	0	9999
Light duration	Milliseconds — time the LEDs stay on, starting after the shutter lag has passed	0	109
Post shot delay	Milliseconds — wait time between pictures (800 ms is a good start; lower for faster cameras)	0	9999

Example — fire all four LEDs at 50% power, 10 ms press, 50 ms lag, 5 ms light, 800 ms post-shot delay:

ALL_E,50,10,50,5,800

OLAT_E

Shoots four pictures, one per LED, firing each in sequence, using the camera's electronic shutter instead of a physical shutter trigger. Camera-agnostic — use with any camera in electronic shutter mode.

Parameter	Values	Min	Max
Power level	Percent %	0 (OFF)	100
Shutter press duration	Milliseconds — time the shoot button is held down (10 ms is a good start)	0	9999
Shutter lag	Milliseconds — time from button release until the shutter curtain opens	0	9999
Light duration	Milliseconds — time the LEDs stay on, starting after the shutter lag has passed	0	109
Post shot delay	Milliseconds — wait time between pictures (800 ms is a good start; lower for faster cameras)	0	9999

Example — shoot 4 OLAT images at 50% power, 10 ms press, 50 ms lag, 5 ms light, 800 ms post-shot delay:

OLAT_E,50,10,50,5,800

N_LIGHTS_E

Shoots one picture with a chosen subset of the four LEDs, using the camera's electronic shutter instead of a physical shutter trigger. Camera-agnostic — use with any camera in electronic shutter mode.

Parameter	Values	Min	Max
Power level	Percent %	0	100
LED1	0 = OFF, 1 = ON	-	-
LED2	0 = OFF, 1 = ON	-	-
LED3	0 = OFF, 1 = ON	-	-
LED4	0 = OFF, 1 = ON	-	-
Shutter press duration	Milliseconds — time the shoot button is held down (10 ms is a good start)	0	9999
Shutter lag	Milliseconds — time from button release until the shutter curtain opens	0	9999
Light duration	Milliseconds — time the LEDs stay on, starting after the shutter lag has passed	0	109
Post shot delay	Milliseconds — wait time between pictures (800 ms is a good start; lower for faster cameras)	0	9999

Example — fire LEDs 1 and 3 at 50% power, 10 ms press, 50 ms lag, 5 ms light, 800 ms post-shot delay:

N_LIGHTS_E,50,1,0,1,0,10,50,5,800

SHOOT_BLANK

Performs a single DSLR shot with no lights. The duration controls how long the shoot pin is physically pressed.

Different cameras require different durations to reliably actuate the shutter:

Normal range: 20–50 ms
Fast-shooting cameras: 5–10 ms
Slow-shooting cameras: 50–200 ms

If the duration is too short the camera will not trigger. If it is too long the camera may fire two shots instead of one.

Parameter	Min	Max
Duration	0	1000

Example — trigger a single shot with the shoot pin held for 30 ms (normal-range camera):

SHOOT_BLANK,30

LED_FAN

Controls the LED cooling fans.

Parameter	Values
Enable	0 = OFF, 1 = ON

Example — turn the fans on:

LED_FAN,1

DIGITAL_POLARIZER

Enables or disables the digital polarizer.

Parameter	Values
Enable	0 = OFF, 1 = ON

Example — enable the polarizer:

DIGITAL_POLARIZER,1

REMOTE_IN

Enables or disables the LA⁴ remote input state machine.

Parameter	Values
Enable	0 = OFF, 1 = ON

Example — enable remote input:

REMOTE_IN,1

When building a sequence, put REMOTE_IN,0 as the first command to hand off control from the remote input state machine before the sequence runs, and REMOTE_IN,1 after the sequence to hand control back to remote input.

REMOTE_IN,0
DIGITAL_POLARIZER,0
ALL_NIKON,100
REMOTE_IN,1
MODEL_LIGHT,100

Example sequence CSV file

LED_FAN,1
REMOTE_IN,0
ALL_CANON,80,105
REMOTE_IN,1
MODEL_LIGHT,30

This sequence does five things in order:

LED_FAN,1 — turns on the cooling fans before the flash LEDs fire.
REMOTE_IN,0 — disables remote input so the state machine hands off control before the sequence runs.
ALL_CANON,80,105 — fires all four LEDs simultaneously at 80% power with a 105 ms on-duration, triggering one shot on a Canon camera.
REMOTE_IN,1 — re-enables remote input, handing control back after the sequence completes.
MODEL_LIGHT,30 — turns on the constant model light at 30% power, providing continuous illumination for framing.

Sending a sequence to LA⁴. Example cross-polarization

The sequence file is written and executed by sending a cmd request to the pycom networking software running on the device. You need to compose a shell command to write the CSV content to ~/la4_sequence.csv, then call boardiocli uSeq to load it and boardiocli runSeq to run it.

The example below captures two shots with a Nikon camera: one without the digital polarizer and one with it. This is a common cross-polarization technique — the first shot captures both diffuse and specular light, the second suppresses specular reflections, leaving only diffuse.

{
    "type_": "cmd",
    "command": "echo \"REMOTE_IN,0\\nDIGITAL_POLARIZER,0\\nALL_NIKON,10\\nDIGITAL_POLARIZER,1\\nALL_NIKON,1\\nREMOTE_IN,1\" > /home/rigsters/la4_sequence.csv && boardiocli uSeq && boardiocli runSeq",
    "id": "31548ca2",
    "name": "My PC App",
    "ip": "192.168.0.100",
    "port": 5000,
    "version": "0.1.0",
    "coordinator": true
}

The sequence file this writes to the node:

REMOTE_IN,0
DIGITAL_POLARIZER,0
ALL_NIKON,10
DIGITAL_POLARIZER,1
ALL_NIKON,1
REMOTE_IN,1

REMOTE_IN,0 — disables remote input so the state machine hands off control before the sequence runs.
DIGITAL_POLARIZER,0 — disables the polarizer so the first shot captures both diffuse and specular light.
ALL_NIKON,10 — fires all four LEDs at 10% power and triggers one shot.
DIGITAL_POLARIZER,1 — enables the polarizer to suppress specular reflections.
ALL_NIKON,1 — fires all four LEDs at minimum power and triggers a second shot, now capturing only diffuse light.
REMOTE_IN,1 — re-enables remote input, handing control back after the sequence completes.

Command reference​

MODEL_LIGHT​

FOCUS_LIGHT​

ALL_NIKON​

OLAT_NIKON​

N_LIGHTS_NIKON​

ALL_CANON​

OLAT_CANON​

N_LIGHTS_CANON​

ALL_SONY​

OLAT_SONY​

N_LIGHTS_SONY​

ALL_E​

OLAT_E​

N_LIGHTS_E​

SHOOT_BLANK​

LED_FAN​

DIGITAL_POLARIZER​

REMOTE_IN​

Example sequence CSV file​

Sending a sequence to LA⁴. Example cross-polarization​