GPIO Edge Automation: Trigger Workflows from Raspberry Pi and SBC Pins

GPIO pins are the foundation of hardware automation — buttons, sensors, relays, motion detectors, switches, and embedded devices all expose digital signals that change state. The GPIO Connector allows your workflows to react instantly to these transitions, making it ideal for Raspberry Pi, Linux SBCs, and edge‑hardware automation.

The connector definition states that it can "monitor GPIO pins on edge hardware and trigger workflows on edge transitions." It supports rising edges, falling edges, or both, with configurable pull modes and debounce logic.

Step 1: Add the GPIO Edge Node

To react to hardware events, drag a GPIO Edge node onto the canvas (Triggers panel).

Configure the following settings:

• pin — BCM pin number (e.g., 17, 22, 27)
• edge — Rising, Falling, or Both
• pullMode — None, PullUp, PullDown
• debounceMs — debounce time in milliseconds

The node listens for transitions using System.Device.Gpio and fires a workflow run whenever the pin changes state.

Step 2: Enable the Trigger in the Jobs Panel

To activate the trigger, open the Jobs panel and enable:

Trigger Type: GpioEdgeTrigger

Use the same settings as the node:

• pin
• edge
• pullMode
• debounceMs

Once enabled, the workflow will fire automatically whenever the hardware pin transitions.

Step 3: Understand the Trigger Payload

When the pin changes state, the trigger produces a payload with:

• pin — the GPIO pin number
• edge — Rising or Falling
• timestamp — ISO‑8601 UTC timestamp

Example payload:

{
"pin": 17,
"edge": "Rising",
"timestamp": "2026-06-05T14:22:11.482Z"
}

This payload can be consumed by any downstream node — MQTT, HTTP, Serial, Local LLM, etc.

Step 4: Build Hardware‑Driven Automations

Once GPIO events enter your workflow, you can combine them with any other connector:

• Publish MQTT messages when a button is pressed
• Send HTTP requests to local APIs
• Trigger alerts via Telegram or Email
• Log hardware events to a database
• Control relays or actuators based on pin transitions

GPIO becomes a powerful real‑world input for automation.

Step 5: Example Automation

Here’s a complete example using GPIO + MQTT:

“When GPIO pin 17 goes high on Raspberry Pi, publish to MQTT.”

Workflow:

1. GPIO Edge (pin 17, Rising)
2. MQTT Publish topic: home/garage/button payload: {{$input.payload}}

When the pin transitions, the trigger fires → the MQTT node publishes the event → Home Assistant or any MQTT consumer reacts instantly.

Step 6: Hardware Use Cases

GPIO triggers are ideal for:

• Door sensors
• Motion detectors
• Physical buttons
• Limit switches
• Relay feedback signals
• Industrial edge devices

With debounce, pull modes, and edge selection, you can build reliable hardware automations.

What's Next?

Try combining GPIO with connectors like MQTT, Serial Bus, OPC UA, HTTP, or Local LLM. Build smart home automations, physical dashboards, or edge‑AI agents that react to real‑world signals.

GPIO unlocks hardware‑level automation — and this connector makes it simple, reliable, and deeply integrated.