Wired Controllers

GPIO-based hardware controllers provide physical switch control for OWL units. These connect directly to the Raspberry Pi GPIO pins and allow tactile control of detection, recording, and sensitivity settings.

A CAN FD-based controller is also in development for better scalability.

Ute Controller

Advanced Controller

Ute Controller

Advanced Controller

USB Drive Required

You MUST connect a USB drive when using a controller, otherwise it will not start. The SanDisk Ultra Fit Flash Drive fits within the enclosure.

Tools Required

  1. Crimping tool for Amphenol crimped connections

  2. Pliers

  3. Wire strippers/cutters

  4. Soldering iron/solder

Ute Controller

Suitable for connecting a single OWL device. TinkerCAD model available here.

Parts List

Component

Quantity

Link

Car cigarette lighter socket

1

Link

7 strand, 3mm (7.5A) trailer cable

As needed

Link

M12 Cable gland

2

Link

Off-On SPST Toggle Switch

2

Link

Rubber boot for switch

2

Link

Amphenol Fathom Lock - 6 pin plug

1

Link

#16 Contacts (13A rated)

3

Link

#20 Contacts (5A rated)

3

Link

Dialight 12V Green LED Panel Mount

1

Link

Dialight 5V Red LED Panel Mount

2

Link

M3 Heatset inserts + screws

3 + 3

Link

Ute Controller Wiring

Purpose

Colour

GPIO Pin

Connector Pin

Power +12V

Red

N/A - connect to 12V of OWL Driver Board

A (#16)

Power GND

Black

N/A - connect to GND of OWL Driver Board

B (#16)

Recording/Detection Toggle Switch

White

BOARD 37

C (#16)

Recording status LED (blinks on image save)

Green

BOARD 38

D (#20)

Storage status indicator

Yellow

BOARD 40

E (#20)

GPIO GND

Brown

BOARD 39

F (#20)

Advanced Controller

Suitable for connecting up to four OWLs. As OWL count increases, increase current ratings accordingly. For four OWLs, use four-pole switches and input power rated at least 40A @ 12V.

TinkerCAD models (1, 2, and 4 OWLs) available here.

Parts List (Core Components)

Component

Quantity

Link

In-line fuse + holder (10A per OWL)

1

30A MAX / 60A MAX

7 strand, 3mm trailer cable (comms)

As needed

Link

Output power cable (min 10A)

As needed

Link

Input power cable (10A per OWL)

As needed

10A / 25A / 50A

M16 Cable gland

1

Link

Rubber boot for switch

4

Link

Amphenol Fathom Lock - 8 pin plug

2 per OWL

Link

Amphenol Fathom Lock - 8 pin receptacle

1 (+ 1 for OWL backcover)

Link

#16 Contacts male (13A)

16 per OWL

Link

#16 Contacts female (13A)

8 (+ 8 for backcover)

Link

Dialight 12V Green LED

1

Link

Dialight 5V Red LED

1 per OWL

Link

Switches by OWL Count

1 OWL Controller:

  • Off-On SPST Toggle Switch (16A MAX) x 3

  • On-Off-On SPST Toggle Switch x 1

4 OWL Controller:

  • POWER SWITCH: Off-On SPST Toggle Switch (50A MAX) x 1

  • Off-On 4PST toggle switch x 2

  • On-Off-On 4PST toggle switch x 1

Advanced Controller Wiring

Purpose

Colour

GPIO Pin

Connector Pin

Power +12V

Red (separate cable)

N/A - connect to 12V of OWL Driver Board

A (#16)

Power GND

Black (separate cable)

N/A - connect to GND of OWL Driver Board

B (#16)

All nozzles on

Blue (trailer cable)

BOARD 36

C (#16)

Recording toggle

Green (trailer cable)

BOARD 38

D (#16)

Sensitivity toggle

Yellow/Orange (trailer cable)

BOARD 40

E (#16)

Status LED

White (trailer cable)

BOARD 37

F (#16)

Spot spray enable

Red (trailer cable)

BOARD 35

G (#16)

GPIO GND

Brown (trailer cable)

BOARD 39

H (#16)

Note

The Advanced controller uses BOARD 37 for the status LED by default. If you are using a Sixfab 4G HAT (which also uses BOARD 37), you will need to remap the status LED to an unused pin in GENERAL_CONFIG.ini. The UTE controller does not have this conflict — it uses BOARD 40 for the status LED.

3D Printed Enclosures

File

Image

STL

Ute Controller Base

image

Link

Ute Controller Top

image

Link

Advanced Controller Base

image

Single / Double / 4 OWL

Advanced Controller Top

image

Single / Double / 4 OWL

Making Connections

Connections can be either soldered with heat shrink or connected with automotive-style blade fittings.

LEDs should be carefully soldered and covered with heat shrink.

Crimp connections for Amphenol Fathomlock connectors work best with a crimping tool. Check quality by tugging gently. Improperly crimped connections can cause problems and/or create fire risk.

Cable Protection

A Nylon Hose Protector sleeve will increase the lifetime of cabling without adding too much expense.

Config File Settings

Update the controller section of GENERAL_CONFIG.ini:

[Controller]
# choose between 'none', 'ute' or 'advanced'
controller_type = none

# Shared LED pins (BOARD numbering)
status_led_pin = 40
gps_led_pin = 38

# Ute controller (single switch)
switch_purpose = recording
switch_pin = 36

# Advanced controller (multiple switches)
detection_mode_pin_up = 36
detection_mode_pin_down = 35
recording_pin = 33
sensitivity_pin = 32

Ute Controller: The toggle switch can be used for either toggling recording or detection. Select this mode with switch_purpose. When a UTE controller is active, only the control matching switch_purpose is locked on the dashboard — the other control, nozzles, sensitivity, and fan remain controllable from the web interface.

Advanced Controller: The sensitivity switch cycles through built-in presets (Low and High) stored as [Sensitivity_Low] and [Sensitivity_High] sections in GENERAL_CONFIG.ini. Custom presets can also be saved from the dashboard. When active, recording, detection, and sensitivity are locked on the dashboard.

Warning

Sixfab 4G HAT users: If you have a Sixfab Base HAT for cellular/GPS, do not use pin BOARD 37 for any OWL function — the Sixfab HAT uses that pin to control modem power, and toggling it (e.g., with a blinking LED) will repeatedly power-cycle the modem. The default pin assignments have been moved to avoid this conflict (switch_pin to BOARD 36, status LED to BOARD 40).

Final Steps

With config files set, save them to the OWL, reboot, and you should be ready to go!

Next Steps