Open hardware · CERN-OHL-S v2

Fork it. Build it. Improve it.

Every Field Station is its own bill of materials. Schematics, gerbers, firmware, enclosure CAD and assembly notes live on GitHub under a share-alike open hardware license. There is no proprietary stack.

Difficulty
Intermediate
Soldering + KiCad
Time
~ 8 hours
Including enclosure
Parts cost
≈ $180
BOM at qty 1
Tools
Iron · Hot-air
Optional reflow
Repositories

Everything you need, in one org.

Bill of materials · excerpt

~ 48 line items, ≈ $180.

RefPartMfr / MPNQtyCost (USD)
U1MCU · ESP32-S3-WROOM-1Espressif1$4.20
U3Charge IC · LiFePO₄ buckTI BQ257981$3.90
U5PM sensorPlantower PMS50031$18.40
U6Temp/RHSensirion SHT401$3.10
U7VOCSensirion SGP411$4.80
U9CameraOmniVision OV26401$6.40
MIC1MEMS microphoneKnowles SPH06451$2.10
BAT1LiFePO₄ 18650 1500 mAhA-grade1$8.20
PV1Solar panel 3.4 W mono-SiVoltaic P1151$24.00
E1Enclosure · IP67 PCHammond 1554F1$22.50
+ 38 more passives, connectors, fasteners…≈ $180 total
Assembly · overview
  1. Step 01

    Order the PCB

    Send the gerbers in /pcb/main and /pcb/sensor to JLCPCB or your fab of choice. 4-layer, 1.6mm, ENIG finish.

  2. Step 02

    Place the SMD parts

    We use a stencil + hot-plate reflow. Hand-solder is also documented; a steady iron and 0.4mm solder are enough.

  3. Step 03

    Through-hole + modules

    Add the LoRa/LTE module, antenna connector, JST cells. Test power rails before installing the MCU.

  4. Step 04

    Flash firmware

    esp-idf 5.2+ · `idf.py flash`. The first boot generates a station ID and shows it on the BLE provisioning channel.

  5. Step 05

    Calibrate

    30-minute warm-up against a reference probe. Calibration offsets are written into NVS.

  6. Step 06

    Mount it

    Strap, screw, or epoxy to any vertical surface with at least 4 hours of direct sun. The station does the rest.