FrostMast

How it fits together

FrostMast, part by part

Scroll or tap a part. Press “See the 3D CAD design” to watch the model, built from our CAD, light each part up and show how it connects.

See the 3D CAD designShow the concept

Real-time 3D render · drag to rotate · final design may varySwipe sideways to rotate

1. 01

   The whole FrostMast

   A post-mounted head reads air, dew point, bud and sky temperature, rings a house bell and can call a wind machine.

2. 02Brain

   RAK3272S (RAK3172)

   The brain: it runs the frostmast-head program

3. 

   03

   Air and dew sensor

   Reads air temperature and humidity inside a ventilated shield

   RAK3272S (RAK3172) · I²C (4 wires) · Air temperature, humidity

4. 

   04

   Bud IR thermometer

   Aimed at a branch to read bud temperature

   RAK3272S (RAK3172) · I²C (SMBus) · Bud temperature

5. 

   05

   Sky IR thermometer

   Tells a clear frost night from cloud or wind

   RAK3272S (RAK3172) · I²C (SMBus) · Sky temperature

6. 

   06

   Two AA lithium cells

   Power the head for seasons, down to -40 °C

   RAK3272S (RAK3172) · 3 V power leads · Battery power

7. 07

   LoRa radio and antenna

   Sends 12-byte readings to the house bell and fan relay

   FrostBell (XIAO ESP32-C3) · LoRa radio, AES encrypted · 12-byte readings

8. 

   08

   ColdSpot stake

   Reads air temperature at another spot in the block

   RAK3272S (ColdSpot) · LoRa radio · Air temperature, dew point

9. 

   09

   DewSpot dummy leaf

   Shows when a greenhouse leaf is wet or near dew point

   RAK3272S (ColdSpot) · 4-core lead, ADC pins · Leaf wetness, leaf temperature

10. 10

    All connected

    8 key parts, one program, and your phone

The idea

The frost probe on the orchard post, made smart: it watches the buds and the sky, and starts the wind machine only when it helps

How the parts connect

FrostMast, wired up

Every part, what links it to the brain, and how the data reaches your phone. A solid line is a cable; a dashed line is a radio link.

The program

What controls FrostMast

void loop() {
    ir_power(true);                          // load switch on
    air = sht45.read();                      // I2C: temperature, humidity
    bud = mlx_bud.objectTemp();
    sky = mlx_sky.objectTemp();
    ir_power(false);
    dew = dew_point(air.t, air.rh);
    state = next_state(state, bud, sky - air.t, crit_temp);
    frame = pack(head_id, seq++, air.t, dew, bud, sky - air.t, batt());
    lora_send(aes128(frame, farm_key));      // 12 bytes
    deep_sleep(state == FROST_NIGHT ? 60 : 300);   // seconds
}

To your phone

How the data reaches FrostMast bell page and app

Grower's phone browser

1. Frost head
2. LoRa radio
3. FrostBell in the house
4. Wi-Fi · web page and push
5. Phone

Key specs

Targets for production units; they may change during development.

Pricing

Target pricing: $249 per head, $349 Wind Machine Kit (2 heads + FanLink), $79 per ColdSpot stake, $299 Frost Map Kit (4 ColdSpots + FrostBell), FrostBell included. $89 per DewSpot, $349 Greenhouse Kit (4 DewSpots + FrostBell). Estimated BOM about $117 per head at qty 1 (about $55 at qty 1,000), FanLink $38, FrostBell $26, ColdSpot about $44. DewSpot about $49 (est.).

Indicative launch pricing in USD, excluding taxes and shipping. Final pricing is confirmed before any balance is charged.

1. 29 Oct 2026, 07:42LatestOrchard and vineyard growers start wind machines from one air probe at one setting all spring, while on clear calm nights the buds run colder than the air and early buds take far more cold than that setting (WSU and MSU frost guides, sources in DESIGN.md).

   • Drawn idea plan (idea.json): a sloping apple block from above with the tree rows, the wind machine and its reach, the frost post, a cold pocket at the low end and the grower’s house; pins for the frost post head, the tower head and FanLink, a ColdSpot stake and the FrostBell
   • The product picture is now this drawn plan instead of the plain fallback card; drawn from the design notes, not the CAD
   • What the plan keeps from the market work: it starts the fan only when the buds need it and there is warm air to bring down, and the machine’s own safety stays in charge
   • Next: more drawn plans for catalogue products that still show the fallback card, then close-out C5 (buyer review prep for sports) from 12:00

   See it in 3DFull research and design

2. 27 Oct 2026, 05:10A mixed farm with an orchard next to its stock paddock pays for a frost alarm, a trough monitor, a crop-raid flasher and a pest-trap camera, each with its own pole, power and app. Commercial versions cost about $389–1,252 for a frost alarm (Onset, fruitweb), A$749–1,290 for a trough monitor (Farmbot) and about $2,700 for a trap camera (iScout, Perennia).

   • Combined into FarmMast (https://iemilabs.com/products/farmmast/); FrostMast itself is unchanged

   See it in 3DFull research and design

3. 26 Oct 2026, 04:18Greenhouse and tunnel growers need a warning before their plants reach the dew point at dusk, so they can vent and heat in time, and a count of how long the leaves stayed wet. University of Connecticut IPM advice says plants that go through the night wet invite grey mould, and Greenhouse Grower notes that leaves can be wet while the humidity sensor at head height still reads safe.

   • New CAD part: DewSpot hanger with a crop-wire hook, a rod the ColdSpot clamps to and a tray for a dummy leaf; 4 of 4 fit checks pass
   • Hardware: a wetness board and a temperature bead as the dummy leaf; about $4.40 per hanger, $49 per DewSpot (est.)
   • Software: "vent and heat now" when the leaf is within 1 °C of the dew point, "leaves wet" alerts and wet hours per bay each morning
   • Design doc: dated section with 6 sources, a dew-margin model and 3 new tests
   • Product page: summary, highlights, a greenhouse use case, pricing ($89 DewSpot, $349 Greenhouse Kit) and 2 new FAQs

   See it in 3DFull research and design

4. 26 Oct 2026, 00:18In the April 2026 freeze in Virginia and Maryland, damage inside one vineyard ran from 0 to 100% depending on where you stood, because cold air sinks into the low rows; growers now need to know where the cold pools to decide what to protect and replant (DM Wine Line, WJLA, Vinetur).

   • New CAD parts: ColdSpot stake case with a 3-ring radiation shield and a V-clamp for 10–25 mm stakes, and its lid; 18 bought-part checks pass, lid on case 0 mm³
   • New CAD reports: how much colder a low spot gets than a mid-slope post, how much earlier its alarm rings, and battery life (about 30 seasons on paper, est.)
   • BOM: about $44 per ColdSpot at qty 1; Frost Map Kit of 4 stakes + bell about $203 (est.)
   • Design doc: dated section on the April 2026 cold-pocket losses with 5 sources and 3 new tests
   • Product page: summary, problem, highlights, use cases, FAQs, specs, pricing and kit contents updated for ColdSpot stakes

   See it in 3DFull research and design

5. 25 Oct 2026, 18:29A probe reads air, but on clear nights buds run colder (WSU) → a 5 deg infrared thermometer aimed down at a fruiting branch, plus a sky sensor that tells a radiation night from cloud

   • New design: 4 printed parts in code CAD, bought parts fit-checked
   • Market research, hardware list and use case written up
   • Design page and kit render published
   • Product page added

   See it in 3DFull research and design