Custom IoT soil sensors, 4K visual tracking, and real-time telemetry—engineering high-elevation organic growing in Nevada’s Carson Valley.
The stream loads only when you click. It's high-resolution (about 16 Mbps), so Wi-Fi is better than mobile data.
Readings from our own probes in the raised bed and our garden weather station. Pick a time range; hover or tap a chart to read every value at that moment.
Three DS18B20 probes: Probe 1 on a Wi-Fi board, Probes 2 and 3 on battery-saving Nordic boards that report over Bluetooth every 5 minutes. Dashed lines mark changes such as moving a probe, watering or feeding; hover a label for details. The tiles above show where each probe is now.
We measured the compost pile from Oct 14 to Oct 25, 2026; then all three thermometers moved to the raised bed. This chart shows the pile's readings while they're still inside the selected range. The compost pile archive →
104°F, active: heat-loving (thermophilic) microbes have taken over and are breaking material down fast. 131°F, kills pathogens & weed seeds: the U.S. EPA standard for safe compost (40 CFR 503, “Process to Further Reduce Pathogens”) is at least 131°F (55°C) held for 3 days in a static pile, or 15 days with 5 turnings in an open row. 150°F, turn it: this pile is about ¾ clay, which packs tight and holds water, so it runs short of air sooner than a normal pile. Turning it lets heat out and air in. 160°F, too hot: above about 160°F (71°C) the useful microbes start dying, so the pile slows down, dries out or goes sour.
Shaded bands: 131–150°F is where the compost breaks down fastest. 70–105°F is where the clay actually improves: once the pile cools, fungi, bacteria and worms glue the clay particles into crumbs so water drains and roots get through. So the plan is hot first (clean, fast breakdown), then 4–8 weeks of cool, damp curing.
This pile is kitchen scraps and garden plants (no manure) mixed into clay, so the risk to next season’s beds is low. The hot phase is mainly about:
All of these die at 131°F held for about 3 days. The outside of a pile stays cooler, so it gets turned (outside to the middle) and allowed to reheat, about twice.
Heat does not kill everything. Plants with mosaic virus, plants that died of Fusarium or Verticillium wilt, and clubroot-infected brassica roots stay out of the pile. Manure and pet waste stay out too.
The plan: pass 131°F, hold about 3 days (the “Compost ≥ 131°F” tile above counts it), turn and reheat, turn early if it reaches 150°F, then cure 4–6 weeks. Before it goes into the beds, a few radish or lettuce seeds sown in a pot of it should come up healthy.
Four RS485 probes in the raised bed, read every minute (XIAO ESP32-C6, sent over Bluetooth). Same time range as above.
Higher EC means more dissolved salts and nutrients.
N, P and K on probes in this class are estimated from conductivity, so they show trends, not a lab test. Bed probe 4 doesn't measure them.
Only Bed probe 1 has a pH electrode. 6.0–7.0 suits most vegetables.
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A whole day in under a minute: one frame every 30 seconds from sunrise to sunset, built each night from the camera's recordings, with the garden sensors' readings at each moment. Drag the slider or step through it frame by frame.
A full-resolution 12 MP photo of the beds three times a day, with the weather at that moment. Every photo is archived permanently.
The one custom-built sensor behind "In the garden": what it measures, how it's wired, and how its readings reach this page every minute.
What's being built, tested or measured in the garden right now.
Builds, experiments and timelapses from the beds.
How the sensors, camera and hub in this garden work.
A Raspberry Pi 5 runs Home Assistant and a Mosquitto MQTT broker as the garden hub. A DFRobot FireBeetle 2 ESP32-C5 on battery reads a DS18B20 temperature probe buried in the compost pile every 5 minutes. A separate always-on weather station, a Seeed XIAO ESP32-C5 with a BME280 sensor, measures air temperature, humidity and barometric pressure in the garden every minute, and doubles as a Bluetooth proxy for Home Assistant. A second compost thermometer, a Seeed XIAO nRF52840 with its own DS18B20 probe, runs on a 1,000 mAh battery and sends its reading over Bluetooth every 5 minutes through the weather station, which acts as a Bluetooth proxy. A Luxonis OAK-1-W-PoE camera streams the beds live in 4K H.265 from a second Raspberry Pi 5.
The Luxonis OAK-1-W-PoE encodes 4K at 30 fps in H.265 on the camera itself, so the Raspberry Pi only stores 10-minute clips and repackages the stream as HLS. A Cloudflare Tunnel exposes just the live stream, and Cloudflare's edge caches each 2-second segment, so the home connection sends it once per location instead of once per viewer.
A waterproof DS18B20 1-Wire digital probe, currently buried in a compost pile (¼ compost, ¾ clay) to track composting heat, is read at 12-bit resolution (0.0625 °C steps) every 5 minutes, and bad readings are skipped so they never reach the chart. Air temperature, relative humidity and barometric pressure come from a BME280 sensor on our garden weather station, read every minute; its pressure is converted to sea level the way airports report it, so it can be compared with Minden-Tahoe Airport. Since October 17, 2026 a second DS18B20 in another spot of the same pile is read every 5 minutes by a battery-saving Nordic nRF52840 board and sent over Bluetooth, so the two can be compared.
Since October 17, 2026 a second DS18B20 probe sits in the compost pile, read by a Seeed XIAO nRF52840, a Bluetooth Low Energy chip from Nordic Semiconductor known for very low power use. It has no Wi-Fi: every 5 minutes it wakes, takes one reading, broadcasts it for a few seconds as a Bluetooth advert in the open BTHome format, then sleeps again drawing only microamps. The garden weather station hears it as a Bluetooth proxy and passes it to Home Assistant on the garden Pi, which stores it with the other readings. The first compost board, an ESP32-C5, has to join Wi-Fi every time it reports, which takes about 100 mA for a few seconds, so on two 18650 cells it lasts roughly two months between charges at one reading every 5 minutes. The Nordic board has only a 1,000 mAh battery, but at an average of about 0.05 mA it should run around a year on a charge (an estimate, not yet measured). Two probes in the same pile also show how much the temperature changes from one spot to another.
131°F (55°C) is the U.S. EPA standard for compost that kills pathogens and weed seeds (40 CFR 503, Process to Further Reduce Pathogens): at least 3 days at or above 131°F in a static pile, or 15 days with 5 turnings in an open row. Above about 160°F (71°C) the useful microbes start dying, so this ¾-clay pile gets turned at about 150°F to let heat out and air in.
With no manure, the main targets are plant diseases from last season's plants (early blight, Septoria leaf spot and late blight on tomatoes and potatoes, powdery mildew, grey mould, white mould, and the damping-off organisms Pythium and Rhizoctonia), weed seeds and volunteer vegetable seeds, and Salmonella or Listeria only if meat, fish, dairy or raw egg went in. All of these die at 131°F held for about 3 days, with the pile turned so the cooler outside reaches the hot middle. Heat does not reliably kill mosaic viruses, Fusarium or Verticillium wilt resting spores, or clubroot, so those plants are kept out of the pile, along with manure and pet waste.
Current area conditions (temperature, humidity, dew point, wind) are the latest National Weather Service observation from Minden-Tahoe Airport (KMEV), about 4 miles away; wet-bulb temperature is calculated from them. The 7-day forecast, frost warning and watering tip come from the Open-Meteo model. The barometric pressure, and the garden's own air temperature and humidity, come from our weather station in the garden.
Yes. The parts are off-the-shelf: an ESP32 board, a DS18B20 probe, a BME280 sensor, a Raspberry Pi running Home Assistant, and optionally a PoE camera. The current projects section lists what is running, what is being rebuilt and what comes next, and the YouTube channel @pjcwalina covers the builds.
Questions about a project, a sensor setup, or something you saw on the camera? Send a note; it comes straight to me.