Protect pipes this winter
Set freeze thresholds, add a wet/dry leak contact, wire alerts, and see how a real cold snap or pad leak looked in the stories.
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About ProbeHarbor
Open-source guides on probes, freeze/flood alerts, firmware, and the stack behind ProbeHarbor. Prefer a shorter list? Start on the guides hub.
Choose a path
Job-based journeys through the guides, start with the outcome you care about, then dig into topics.
Wire my first DHT22
Sensor basics, pin wiring, and the Arduino sketch that publishes JSON.
Open Arduino overviewPush from ESP / Pico / MCU / AVR asm
Create a push device, POST so sensors auto-import, and optional OTA / QR stickers.
- Add push or pull
- Buy ESP32 kit
- Or flash Pico W
- Or flash STM32
- Or flash CH32V
- Or AVR assembly
- Or cellular LTE
- Or Teensy 4.1
- Or PIC18 Ethernet
- Ingest API
- Kit QR
- Flash ESP32
- ESP32 OTA
Understand my readings
Why garages swing, how data reaches the site, and how to spot stale feeds.
Try the probe demoShare with my household
Invite family, understand roles, and keep freeze and leak alerts in one place.
Create a free account
Start here
Popular entry points: playbooks, demo, ingest, channels, and household sharing.
- Cold-snap alert playbook A practical checklist so freeze alerts turn into action instead of noise.
- Temperature probe case study Real-world build story: placement decisions, firmware iterations, and what the data showed after deployment.
- Interactive probe demo Garage, workshop, attic, or crawlspace: watch freeze and leak risk and ingest JSON update live.
- Ingest API and alert webhooks Device API keys, typed sensor payloads, SenML and HA REST auto-detect, outbound HMAC webhooks, and Pro alert channels.
- Alert channel cookbook Pick channels that match how your household actually wakes up for cold snaps.
- Household sharing walkthrough Keep probes and alerts in one household without sharing a password.
Find a guide
Search 110 articles or browse by learning path below.
Popular starting points
- Cold-snap alert playbookA practical checklist so freeze alerts turn into action instead of noise.
- Temperature probe case studyReal-world build story: placement decisions, firmware iterations, and what the data showed after deployment.
- Interactive probe demoGarage, workshop, attic, or crawlspace: watch freeze and leak risk and ingest JSON update live.
- Ingest API and alert webhooksDevice API keys, typed sensor payloads, SenML and HA REST auto-detect, outbound HMAC webhooks, and Pro alert channels.
- Alert channel cookbookPick channels that match how your household actually wakes up for cold snaps.
- Household sharing walkthroughKeep probes and alerts in one household without sharing a password.
Probe environments
Probes, placement, and the physics that move readings.
Temperature probes and their uses
Probe types, placement strategies, and why averaging multiple sensors matters in unheated spaces.
Read overviewDeep-dive guides 8
- Temperature probe case study Real-world build story: placement decisions, firmware iterations, and what the data showed after deployment.
- DHT22 sensor overview Single-wire digital sensor, typical accuracy, and minimum read intervals.
- Probe mounting and enclosures Shoulder-height placement away from doors and heat sources in breathable housings.
- Multi-zone garage layout Split the garage into meaningful zones instead of averaging away the signal you need.
- Probe mapping and dashboard labels Stable JSON keys, friendly labels, and feed-level organization for multi-probe setups.
- Humidity and condensation basics Dew point math in plain language and why air temperature alone misses condensation risk.
- Probe cable length limits Keep data lines short, twisted, and away from motor noise for stable JSON feeds.
- Interactive probe demo Garage, workshop, attic, or crawlspace: watch freeze and leak risk and ingest JSON update live.
Temperature changes and what causes them
Sun load, infiltration, doors, HVAC, and stored heat explain most temperature movement in garages, attics, and shops.
Read overviewDeep-dive guides 7
- Garage door temperature swings Infiltration and thermal stratification when the largest wall opening moves.
- Sun load on garage walls Opaque wall heating, delayed interior peaks, and why outdoor weather alone misleads.
- Infiltration, wind, and drafts Chronic leaks versus door events, and what probes reveal about draft paths.
- Seasonal garage patterns Long-horizon context so single-day spikes do not drive bad decisions.
- Thermal mass and concrete slabs Concrete buffers day-night cycles: expect delayed peaks and cold floors after warm afternoons.
- HVAC duct influence on probes Duct leaks and register proximity create localized heat that outdoor weather cannot explain.
- Stored vehicle heat in the garage Hot engines and exhaust surfaces create short-lived microclimates near parked vehicles.
Data & history
Saved snapshots, exports, and how readings reach storage.
Historical temperature data usage
Turn snapshots into charts, alerts, and long-term records for maintenance and seasonal planning.
Read overviewDeep-dive guides 5
- History dashboard browsing Turn stored snapshots into a readable timeline inside the signed-in dashboard.
- CSV export and spreadsheet analysis Subscriber and admin CSV workflows for analysis outside the website.
- Freeze protection thresholds Define risk temperatures from history instead of guessing from outdoor forecasts.
- Spotting data gaps in history Flat lines, stair-steps, and empty ranges usually mean collection stopped, not stable weather.
- Charting history with spreadsheets Turn raw timestamp rows into freeze audits and seasonal comparisons outside the website UI.
End-to-end monitoring data flow
Hardware, relay, website fetch, Supabase storage, and CSV export in one pipeline.
Read overviewDeep-dive guides 6
- Home page probe fetch Guest defaults versus signed-in feed mappings from Supabase.
- Supabase history inserts What triggers a save, what is stored per probe, and guest behavior.
- Debugging stale readings Checklist for curl, cache, auth, and key typos in order.
- Weather API parallel data path External weather data explains garage swings driven by outdoor humidity and wind, not just door events.
- Cookie and session lifecycle Session cookies tie browser identity to Supabase rows for feeds and saved history.
- Caching feed responses end to end Multiple cache layers prevent hammering home uplink while keeping readings fresh enough.
Hardware & firmware
Arduino, ESP32, Pico W, STM32, CH32V, and AVR assembly firmware, wiring, and the local LCD.
Arduino and Arduino sketches
Sketches read probes, format JSON, and publish readings over HTTPS from the monitored space to the web.
Read overviewDeep-dive guides 7
- Arduino IDE setup and flashing Bench setup before mounting hardware in the space.
- Sketch polling and main loop Non-blocking loop design for sensors, network, and local display.
- JSON probe output schema Contract between firmware and every downstream client including this website.
- Firmware watchdog and recovery Watchdog timers, retries, and reboot strategies for unattended installs.
- Serial debugging tips Structured serial output accelerates firmware debug before the board moves to the monitored space.
- Library dependencies for the sketch Pin compatible DHT, LiquidCrystal, and Ethernet stacks prevent compile surprises on fresh laptops.
- Static IP versus DHCP on the Arduino Stable addressing simplifies relay configuration, port forwarding, and mental models for curl tests.
Arduino circuit wiring overview
How USB power, the breadboard, contrast pot, LCD, sensors, and Ethernet shield fit together.
Read overviewDeep-dive guides 5
- Breadboard power rails Clean power rails reduce noise that shows up as bogus humidity spikes.
- Ethernet shield stacking Physical assembly details before locking the board in an enclosure.
- Circuit wiring troubleshooting Systematic checks from power to data lines before replacing parts.
- Ground loop avoidance One intentional ground star point beats mysterious DHT22 timeouts from loop currents.
- Enclosure ventilation for electronics MCU enclosures need airflow; probe boxes need breathable vents: do not treat them the same.
Arduino pin-level wiring
Pin-by-pin map matching the LiquidCrystal constructor and sensor data lines in firmware.
Read overviewDeep-dive guides 5
- LiquidCrystal GPIO map LCD pins must match the sketch exactly or the display stays blank.
- DHT22 data line wiring One data pin per probe with proper pull-up and length limits.
- SPI pins reserved for Ethernet Avoid pin conflicts between the Ethernet stack and local peripherals.
- LCD backlight PWM options Backlight control is separate from LiquidCrystal data pins: wire it deliberately.
- Jumper wire standards for breadboards Consistent wire colors and firm seating prevent intermittent probes after the door shakes the wall.
DHT22 sensors and LCD display
Why two probes show separate readings on the LCD while JSON feeds expose both to the website.
Read overviewDeep-dive guides 5
- DHT22 read errors and retries Retry logic and minimum intervals keep JSON stable in drafty installs.
- LCD local display format Two-line layout conventions for dual-probe controllers.
- Dual-probe averaging logic When to average, when to exclude a failed read, and how history uses avg.
- DHT22 sensor warm-up time First reads after boot can lag; warm-up minutes matter for humidity more than temperature.
- I²C LCD alternative Two-wire I²C LCDs trade pin savings for different library code and address planning.
Backend & website
Python relays, Astro on Cloudflare, and stack comparisons.
Python scripts and JSON feeds
Backend scripts normalize probe JSON, cache responses, and expose stable HTTPS endpoints.
Read overviewDeep-dive guides 6
- FastAPI relay setup Install, configure upstream URL, and verify cached responses with curl.
- Redis cache for feeds TTL tuning, stale-while-revalidate behavior, and restart recovery.
- Relay security and access Harden the relay without complicating the Arduino firmware.
- Docker deployment for the Python relay Container images pin Python dependencies and simplify restart after power blips.
- Environment variables for the relay Twelve-factor style config keeps secrets out of git and simplifies Docker restarts.
- Health check endpoints for relays /health should mean more than 'Python process running': verify Redis and last good upstream fetch.
Astro applications in this project
This site uses Astro for fast pages, authenticated dashboards, and API routes at the edge.
Read overviewDeep-dive guides 6
- Astro server-side rendering SSR pages versus static prerender in this Cloudflare deployment.
- Astro islands and hydration Selective JavaScript where interactivity actually matters.
- Cloudflare Workers deployment Edge hosting for pages, API routes, and assets in one pipeline.
- Middleware auth patterns in Astro Server middleware validates Supabase sessions once per request for protected paths.
- Environment secrets on Cloudflare Wrangler secrets and encrypted vars keep production keys off laptops and out of logs.
- Tailwind CSS v4 setup in Astro Tailwind v4 CSS-first config keeps about prose and dashboard cards consistent.
Next.js and Node applications
Node runtimes excel at APIs and SSR; this project achieves the same goals with Astro on Cloudflare.
Read overviewDeep-dive guides 5
- Next.js for monitoring dashboards Strengths of Next for auth-heavy dashboards versus this Astro stack.
- Node and Express API patterns Where Express still wins and where Python or edge routes are simpler.
- Comparing full-stack options Trade-offs for SSR, auth, billing, and hardware integration.
- WebSocket live updates in monitoring UIs WebSockets shine for sub-minute live tiles; HTTP caching fits public home page scale.
- Hosting cost comparison for monitoring stacks Edge static-first hosting plus a tiny home relay often beats always-on VPS for hobby monitoring.
Dashboard & integrations
Accounts, ingest API, alerts, PWA install, and automation.
Accounts, subscriptions, and dashboard tools
Create an account, connect hardware, configure alerts, invite household members, and upgrade when you need Pro channels.
Read overviewDeep-dive guides 14
- Supabase auth flow How accounts are created and authenticated end to end.
- Stripe CSV subscription Billing flow from checkout to unlocked history download.
- Configuring temperature feeds Pull-feed URLs, JSON root key, probe labels, and troubleshooting.
- Admin dashboard features Tools gated by the admin group for site operators.
- Group membership model Groups encode subscription and operator roles without hard-coding emails in source.
- Contact form admin review Contact submissions land in a review queue gated by admin group membership.
- Display preferences deep dive Display prefs persist per account so shared JSON feeds render in your preferred units.
- Cold-snap alert playbook A practical checklist so freeze alerts turn into action instead of noise.
- Alert channel cookbook Pick channels that match how your household actually wakes up for cold snaps.
- Household sharing walkthrough Keep probes and alerts in one household without sharing a password.
- Garage door + cold alert playbook Stop heat loss and freeze risk when a garage door is left open on a cold night.
- Personal weather stations (Ambient & WeatherFlow) Point ProbeHarbor at the station on your property: better yard-level freeze context.
- Freeze → thaw flood playbook Companion to cold-snap: catch melt and drip floods under water heaters, laundry, and sumps while freeze season ends.
- Time-to-freeze explained Understand the hours-until-freeze clock so you act before the probe crosses your freeze threshold.
Adding push and pull devices
Choose push vs pull, create the device or feed, POST or pull readings, and confirm Home shows live values.
Read overviewDeep-dive guides 9
- ESP32 freeze kit parts list Verified ESP32 + waterproof DS18B20 BOM with stable Adafruit product links and Amazon /dp/ alternatives.
- ESP32 flashing options No hosted one-click binary flasher: download a personalized sketch, then flash with IDE, PlatformIO, or esptool-js.
- Raspberry Pi Pico W ingest RP2040 / RP2350 Wi‑Fi probes: CircuitPython code.py, MicroPython, or Earle Philhower Arduino, DS18B20 on GP4.
- STM32 Zephyr ingest Cortex-M7 Ethernet probe: Zephyr C on Nucleo-F767ZI, DS18B20 on Arduino D4, HTTP to a LAN TLS relay.
- CH32V RISC-V ingest RISC-V Ethernet probe: WCHNET C on CH32V307, DS18B20 on PB12, HTTP to a LAN TLS relay.
- AVR assembly ingest Uno + W5100 in GNU AVR assembly: DS18B20 on D7, HTTP to a LAN TLS relay, not Arduino C.
- Cellular ingest (Particle Boron) LTE freeze probe: Particle Boron + DS18B20 on D2, Particle webhook to HTTPS ingest.
- PIC18F67J60 Ethernet ingest Microchip Ethernet probe: MLA C on PIC18F67J60, DS18B20 on RD0, HTTP to a LAN TLS relay.
- Teensy 4.1 Ethernet ingest Teensy 4.1 + QNEthernet: DS18B20 on pin 4, HTTP to a LAN TLS relay.
Ingest API and alert webhooks
Device API keys, typed sensor payloads, SenML and HA REST auto-detect, outbound HMAC webhooks, and Pro alert channels.
Read overviewDeep-dive guides 5
- Kit QR onboarding Encode the ingest URL on a label so new hardware setup is a single phone scan.
- ESP32 OTA and battery reporting Keep ESP32 firmware current on your LAN while telemetry posts to the ingest API.
- Zapier and Make.com recipes Route alerts to Zapier/Make and pause notifications from other smart-home flows.
- ESPHome and Shelly recipes Copy-paste HTTP POST recipes for common LAN sensors: dual-run with Home Assistant MQTT.
- Home Assistant notify recipes Local voice and phone notify when freeze or leak risk hits: dual-run with ProbeHarbor email/SMS.
Live simulation
Three probes, one space
Watch temperature and humidity shift as sun load, outdoor air, and airflow change conditions zone by zone, just like the live JSON feed.
North wall, door zone, and workbench probes refresh every few seconds—the same rhythm as the live dashboard feed.
Open-source repositories
Projects you can inspect, fork, or adapt for your own build. Programmatic integrations start with the HTTP API and openapi.yaml.
Frequently asked questions
Quick answers before you dive into a guide.
What is covered in the About guides?
Probe placement, DHT22 and Arduino wiring, freeze thresholds, flood/leak contacts, ingest APIs, household sharing, PWA install, and how ProbeHarbor stores and charts readings.
Where should I start?
Pick a job-based journey on this page (freeze protection, flood/leak setup, wiring, ingest, debugging, or household setup), or search the full guide index.
Is ProbeHarbor open source?
Yes: application and firmware-related repos are linked from this hub so you can inspect, fork, or adapt the stack.
Where does ProbeHarbor run?
The website and ingest APIs run on Cloudflare’s edge (Workers). Live job and ingest health is on /system-status: we publish measured health, not a marketing uptime percentage. Stack detail: /about/astro-applications.