Configurator Overview

What is the Configurator?

The Configurator is LoopString's visual editor for building IoT automation systems. Instead of writing code or manually configuring Node-RED, you pick hardware from a library, organize it into rooms, wire everything together on a visual canvas, and deploy to your Raspberry Pi with one click.

Who is this for? Anyone with a Raspberry Pi who wants to automate monitoring and control — whether that's a grow tent, fermentation chamber, server room, or manufacturing line. No programming experience required.

System Requirements

• Raspberry Pi 3B+ or newer (4 recommended) with LoopString agent installed
• Node-RED (installed automatically during Pi setup)
• Internet connection on both the Pi and your browser
• LoopString account (free tier works for getting started)
• Supported browser: Chrome, Firefox, Safari, or Edge (latest versions)

Key Concepts

Before diving in, here are the terms you'll see throughout the Configurator:

Parts

Parts are the building blocks of your automation. Each part represents a physical piece of hardware — a temperature sensor, a relay, a pump, or a PID controller. Parts come from the Parts Library with over 100 pre-built options, and each one includes:

• Hardware configuration (GPIO pins, I2C addresses, serial ports)
• A pre-built Node-RED template that runs on your Pi
• Dashboard widget configuration for monitoring
• Signal definitions describing what data it publishes or consumes

Instances

An instance is one copy of a part added to your project. You can have multiple instances of the same part type — for example, three DS18B20 temperature probes or two relay-controlled pumps. Each instance gets its own configuration (different GPIO pins, different names).

Rooms

Rooms are logical containers for organizing parts. They become tabs on your dashboard. A room might represent:

• A physical space: "Greenhouse", "Fermentation Chamber"
• A system: "Irrigation", "Climate Control"
• A function: "Monitoring", "Alerts"

Every part must belong to exactly one room.

Signals and Typed Ports

Parts communicate through signals — data flowing from one part to another. Each part has a fixed number of input and output ports, and each port has a type:

• number — Analog values like temperature (25.3) or humidity (65)
• boolean — True/false states for on/off switches
• value-unit — Measurements with units like 25°C or 1013 hPa
• object — Complex data like GPS coordinates or multi-field readings

The Configurator prevents you from connecting incompatible signal types — you can't wire a temperature reading into a boolean input.

Drafts

Your work is auto-saved every 15 seconds as a draft. You can:

• Resume editing from where you left off
• Browse and restore previous drafts from the Drafts Picker
• Delete drafts you no longer need
• Compare your current draft against what's deployed on the Pi

Flows

A flow is the complete Node-RED program generated from your rooms, parts, and wiring. The Configurator translates your visual layout into Node-RED JSON and deploys it to your Pi automatically.

How to Use the Configurator

Step 1: Open the Configurator

Navigate to the Configurator page from the main sidebar menu. If this is your first time, you'll see the Setup Wizard. Returning users see their most recent draft.

Step 2: Choose a Starting Point

You have two options:

• Use a Template: Pick from 15+ pre-built project templates covering grow rooms, fermentation, aquaponics, HVAC, manufacturing, and more. Templates come with parts, rooms, and wiring pre-configured. See Using Templates.
• Start from Scratch: The Setup Wizard walks you through selecting a category, choosing your hardware, and picking control strategies step by step. See Creating a Project.

Step 3: Organize into Rooms

Create rooms that match your physical setup. For a grow tent you might have a single "Tent" room. For a brewery, you might create "Fermentation Tank", "Cold Crash", and "Serving". See Adding Rooms and Parts.

Step 4: Add Parts

Browse the Parts Library to add sensors, actuators, and controllers to your rooms. The library is organized by category — temperature, humidity, CO2, relays, pumps, PID controllers, and more.

Step 5: Configure Hardware Settings

Each part needs hardware configuration. Click a part card to expand its settings:

• GPIO pin assignment (which pin on the Pi)
• I2C address for bus devices
• Sample interval (how often to read the sensor)
• Channel numbers for multi-channel boards

The Configurator validates your choices and warns about pin conflicts or address collisions.

Step 6: Wire the Flow

Connect parts together on the visual canvas by dragging lines between output ports (right side) and input ports (left side). A typical flow looks like:

Sensor → Controller → Actuator

For example: Temperature Sensor → PID Controller → Heater Relay. See Wiring Flows.

Step 7: Deploy

When you're happy with your configuration, click Deploy. The system runs pre-deploy validation to catch issues, then pushes the flow to your Pi. You'll see real-time progress as each step completes. See Deploying to Pi.

Configuration Options

Sensor Settings

Minimum sample intervals by subscription tier:

Controller Settings

Actuator Settings

Use Cases

Grow Room Climate Control

Scenario: You have a 4x4 grow tent and want to maintain 75°F / 55% humidity with CO2 supplementation during lights-on.

Parts needed: DHT22 (temp + humidity), MH-Z19 CO2 sensor, Kasa smart plugs (heater, humidifier, exhaust fan, CO2 solenoid), PID controllers.

Setup:

1. Create a "Tent" room
2. Add the DHT22 and MH-Z19 sensors
3. Add Kasa plug actuators for each device you want to control
4. Add PID controllers for temperature, humidity, and CO2
5. Wire: DHT22 temperature → PID → Heater plug, DHT22 humidity → PID → Humidifier plug, MH-Z19 → PID → CO2 solenoid
6. Set setpoints: 75°F, 55% RH, 1000 ppm CO2
7. Deploy

Result: Your Pi continuously monitors the tent and adjusts heater, humidifier, exhaust fan, and CO2 to maintain your targets. The dashboard shows live readings and PID status.

Fermentation Temperature Monitoring

Scenario: You're fermenting beer and need to hold 65°F for 14 days, with alerts if temperature drifts more than 2 degrees.

Parts needed: DS18B20 waterproof temperature probe, Kasa smart plug (for a heat wrap or cooling jacket), hysteresis controller.

Setup:

1. Create a "Fermenter" room
2. Add the DS18B20 probe (set to 1-Wire bus, 30s interval)
3. Add a Kasa plug for the heating/cooling element
4. Add a hysteresis controller (cheaper than PID for simple on/off)
5. Wire: DS18B20 → Hysteresis → Kasa plug
6. Set: target 65°F, hysteresis band ±1°F
7. Set an alarm threshold at ±2°F to get push notifications
8. Deploy

Result: Temperature stays within 1°F of target. You get an alert on your phone if anything goes wrong. The dashboard shows a sparkline trend of the entire fermentation.

Server Room Environmental Monitoring

Scenario: You need to monitor temperature, humidity, and power in a server rack with alerts but no automated control.

Parts needed: BME280 (temp + humidity + pressure), ACS712 current sensor, Pi system metrics (CPU temp, disk usage).

Setup:

1. Create a "Server Rack" room
2. Add BME280 and ACS712 sensors
3. Enable Pi system metrics (CPU temperature, memory, disk)
4. Skip controllers and actuators — this is monitoring only
5. Set alarm thresholds: temp > 80°F, humidity > 60%, current > 15A
6. Deploy

Result: Real-time environmental dashboard with historical charts and analytics. Push notifications if any threshold is breached.

Troubleshooting

"Validation error" when trying to deploy

Cause: The pre-deploy validator detected issues in your configuration.

Fix: Look at the FlowSyncBadge indicator near the Deploy button. Common validation errors include:

• Orphan PID controller: A PID controller isn't wired to both a sensor input and an actuator output. Wire it completely or remove it.
• Signal type mismatch: An output port type doesn't match the connected input. Check the port types on both ends.
• Duplicate GPIO pin: Two parts are configured to use the same pin. Change one of them.
• Missing required field: A part is missing a required setting like GPIO pin or I2C address. Click the part card and fill in the highlighted fields.

Parts not appearing on the dashboard after deploy

Cause: Usually a wiring issue — the part's Node-RED template isn't publishing to the expected RTDB path.

Fix:

1. Check the FlowSyncBadge — it should show "In Sync" after a successful deploy
2. Verify the Pi is online (green indicator in device header)
3. Open the part's config and verify GPIO pin / I2C address matches your physical wiring
4. Try redeploying — sometimes the first deploy after adding new parts needs a Node-RED restart

Deploy stuck on "Waiting for device"

Cause: The Pi isn't responding to the deploy command.

Fix:

1. Check your Pi is powered on and connected to the internet
2. Verify the LoopString agent is running: the device status should show "Online"
3. If the Pi recently restarted, wait 30 seconds for the agent to reconnect
4. If using Tailscale for remote access, confirm the tunnel is active
5. As a last resort, SSH into the Pi and restart the agent: sudo systemctl restart loopstring-agent

PID controller shows "BAD PV" on dashboard

Cause: The PID controller isn't receiving a valid process variable (sensor input).

Fix:

1. In the Configurator, verify the sensor is wired to the PID controller's input port
2. Check that the sensor is actually publishing data (visible on the dashboard)
3. Ensure the signal types match — PID expects a numeric input
4. Redeploy after fixing wiring

Known Limitations

• PID controllers run on the Pi only — the cloud dashboard displays PID status but cannot directly control the feedback loop. This is by design for reliability (the Pi keeps running even if internet drops).
• Sensor slot limits — each subscription tier caps the total number of active sensor instances. A multi-measurement sensor like DHT22 (temperature + humidity) counts as 2 slots.
• One flow per device — each Pi runs a single Configurator flow. For complex setups, use multiple rooms within that flow rather than trying to deploy multiple flows.
• GPIO pin exclusivity — each BCM pin can only be used by one part at a time. Multi-channel HAT boards help when you need more I/O.
• Deploy requires device online — you cannot queue a deploy for later; the Pi must be reachable at deploy time.
• Mobile editing is limited — the mobile Configurator uses a simplified step-based interface. Complex wiring is easier on a desktop browser.

Quick Reference

Next Steps

• Creating a Project — start building from scratch or a template
• Adding Rooms and Parts — organize your hardware
• Wiring Flows — connect sensors to controllers to actuators
• Using Templates — quick-start with pre-built configurations
• Deploying to Pi — push your flow to the Raspberry Pi
• Multi-Device Setups — manage multiple Pis