2 layers142 × 208 mm
2 layers40 × 40 mm
Occupancy
romkey/sensrSensor project hardware - ESP32-S3 base board, light and air sensors
- Size
- 40 × 40 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 35
- Nets
- 41
- Pads
- 161
- Tracks, vias
- 254, 41
- Pours
- 219
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 14 Aug 2025
- Updated
- 5 Nov 2026
Overview
Occupancy is an open-source printed circuit board by romkey, from the romkey/sensr repository on GitHub, published under the MIT licence. It is a 2-layer board of 40 × 40 mm with 35 parts on 41 nets, routed with 254 tracks and 41 vias.
It is built around the ESP32-C3-MINI-1-N4, LD1117-3.3(MS) and MBR140SFT1G-HXY, with the SM04B-SRSS-TB(LF)(SN), TPD2E2U06DCKR-TP and TYPE-C-31-M-12 among its other parts. Its parts include 10 resistors, 5 capacitors, 4 diodes, 3 ICs and 3 connectors. It belongs with the ESP32 and RISC-V boards of this library.
Main components
6
ESP32-C3-MINI-1-N4
SMD,16.6x13.2mm-40℃~+85℃ -98dBm 20.5dBm 350mA 3V~3.6V 84mA Integrated temperature sensor、Integrated antenna、Built-in watchdog On-board PCB Antenna SPI、UART、I2C、I2S、USB Transceiver SMD,16.6x13.2mm WiFi Modules ROHSEspressif SystemsRF Modules
LD1117-3.3(MS)
SOT-2230℃~+125℃@(Ta) 1 1.4V@(1A) 12V 12mA 1A 3.3V Fixed Over Temperature Protection Positive SOT-223 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSMSKSEMIVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
MBR140SFT1G-HXY
SOD-123FLSOD-123FL Schottky Diodes ROHSHXY MOSFETSchottky Diodes
SM04B-SRSS-TB(LF)(SN)
SMD,P=1mm,卧贴-25℃~+85℃ 1 1A 1mm 1x4P 2.9mm 4 4.32mm 4P 50V 6mm Auxiliary Solder Pin Copper alloy PA SH Surface Mount, Right Angle Tin UL94V-0 White SMD,P=1mm,卧贴 Wire To Board Connector ROHSJSTWire To Board Connector
TPD2E2U06DCKR-TP
SOT-323MOSFETsTECH PUBLIC
TYPE-C-31-M-12
SMD-30℃~+80℃ 1 10,000 cycles 16P 20V 5A 7.35mm Female Surface Mount, Right Angle Type-C SMD USB Connectors ROHSHRO ElectronicsUSB Connectors
README
README.mdSensr
Sensr is a group of hardware projects intended for environmental sensing.
It currently consists of:
- base board - ESP32-S3 with accelerometer, I2S microphone header, display header, 2 Qwiic ports, particle counter connector
- air - SCD40 CO2 + BME680 temperature/humidity/pressure sensor
- air-stcc4 - new STCC4 CO2 sensor + SHT40 temperature/humidity sensor
- light - TSL25911 light
- light-ltr390uv - LTR390 UV sensor + TSL25911 light sensor
Sensr is an ESP32 S3-based microcontroller intended for environmental sensing, as well as separate sensor boards.
I2C Addresses
0x29 TSL25911 0x74 AS7331 0x49 AS7341 0x53 LT-390
0x76 BME680 0x62 SCD40 0x59 SGP40 0x5D SFA30 0x44 SHT3X-D
0x6A LSM6DS3TR-C
Gas: 0x64 0x65 0x66 0x67 0x68 0x69 0x6B
bodged I2S
SCK - CS - 10 SD - RESET - 9 WS - DC - 46 L/R - SDI (MOSI) - 16
License
Hardware is shared under the CERN-OHL-S-2.0 license.
Software is shared under the MIT license.
Documentation is shared under the CC-BY-SA-4.0 - Attribution-ShareAlike license.
Parts
35| Qty | Value | Footprint | References |
|---|---|---|---|
| 4 | 10K | Resistor_SMD:R_0402_1005Metric_Pad0.72x0.64mm_HandSolder | R1, R2, R5, R8 |
| 4 | MountingHole_2.2mm_M2 | MountingHole:MountingHole_2.2mm_M2 | MNT1, MNT2, MNT3, MNT4 |
| 2 | 100nF | Capacitor_SMD:C_0402_1005Metric_Pad0.74x0.62mm_HandSolder | C1, C4 |
| 2 | 10µF | Capacitor_SMD:C_0402_1005Metric_Pad0.74x0.62mm_HandSolder | C2, C5 |
| 2 | 4.7K | Resistor_SMD:R_0402_1005Metric_Pad0.72x0.64mm_HandSolder | R6, R7 |
| 2 | 5.1k | Resistor_SMD:R_0402_1005Metric_Pad0.72x0.64mm_HandSolder | R4, R9 |
| 2 | ~ | easyeda2kicad:SW-TH_SKHHNJA010 | SW1, SW2 |
| 1 | 1µF | Capacitor_SMD:C_0402_1005Metric_Pad0.74x0.62mm_HandSolder | C3 |
| 1 | 220 | Resistor_SMD:R_0402_1005Metric_Pad0.72x0.64mm_HandSolder | R3 |
| 1 | 510 | Resistor_SMD:R_0402_1005Metric_Pad0.72x0.64mm_HandSolder | R10 |
| 1 | CTRLH Logo | 1myFootprints:CTRLH Logo | GRPH1 |
| 1 | Conn_01x09_Pin | Connector_PinHeader_2.54mm:PinHeader_1x11_P2.54mm_Vertical | J3 |
| 1 | ESP32-C3-MINI-1-N4 | easyeda2kicad:WIFIM-SMD_ESP32-C3-MINI-1 | U1 |
| 1 | LD1117-3_3 | easyeda2kicad:SOT-223_L6.7-W3.5-P2.30-BR | U3 |
| 1 | LED | LED_SMD:LED_0603_1608Metric_Pad1.05x0.95mm_HandSolder | D1 |
| 1 | LOGO | LOGO | G*** |
| 1 | MBR140SFT1G | EasyEDA:SOD-123F_L2.8-W1.8-LS3.7-RD | D4 |
| 1 | OSHW-Logo2_7.3x6mm_SilkScreen | Symbol:OSHW-Logo2_7.3x6mm_SilkScreen | GRPH0 |
| 1 | PWR | LED_SMD:LED_0603_1608Metric_Pad1.05x0.95mm_HandSolder | D3 |
| 1 | SM04B-SRSS-TB_(LF)(SN) | easyeda2kicad:CONN-SMD_4P-P1.00_SM04B-SRSS-TB-LF-SN | J2 |
| 1 | STHS34PF80TR | easyeda2kicad:LGA-10_L4.2-W3.2-P0.50-BL | U2 |
| 1 | TPD2E2U06DCKR | EasyEDA:SC-70-3_L2.0-W1.3-P0.65-LS2.1-BL | D2 |
| 1 | TYPE-C-31-M-12 | easyeda2kicad:USB-C-SMD_MC-311D | J1 |
The 34 most common of 35 parts.
Questions
How big is the Occupancy PCB?
It measures 40 × 40 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Occupancy use?
35 parts, built around the ESP32-C3-MINI-1-N4, LD1117-3.3(MS), MBR140SFT1G-HXY and SM04B-SRSS-TB(LF)(SN). The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Occupancy KiCad files?
From the romkey/sensr repository on GitHub, at the commit this page was made from: the board is hw/occupancy/occupancy.kicad_pcb and its schematic hw/air-stcc4/0.1.0/air-stcc4.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Occupancy design in my own project?
Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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