{
 "slug": "sensor-watch-lite",
 "name": "Sensor Watch Lite",
 "maker": "Oddly Specific Objects",
 "category": "wearables",
 "categoryLabel": "Wearables",
 "status": "listed",
 "statusLabel": "Listed by maker",
 "description": "A replacement circuit board that turns a Casio F-91W into a programmable ARM Cortex-M0+ watch.",
 "goodFor": "Rewriting the firmware of a watch you already own.",
 "youNeed": "A Casio F-91W to transplant it into, and some soldering for the buzzer.",
 "tradeoff": "No radio; the segment LCD limits what you can show.",
 "tags": [
  "Casio F-91W",
  "ARM Cortex-M0+",
  "Open source",
  "Low power"
 ],
 "price": "US$39",
 "priceShort": "$39",
 "priceFrom": null,
 "checked": "2026-09-18",
 "url": "https://gadgets.sh/devices/sensor-watch-lite/",
 "shortUrl": "https://gadgets.sh/sensor-watch-lite",
 "markdown": "https://gadgets.sh/devices/sensor-watch-lite.md",
 "image": "https://gadgets.sh/assets/sensor-watch-lite.jpg",
 "cutout": "https://gadgets.sh/assets/cutouts/sensor-watch-lite.webp",
 "shareCard": "https://gadgets.sh/og/sensor-watch-lite.jpg",
 "shops": [
  {
   "merchant": "Oddly Specific Objects",
   "label": "Order on Crowd Supply",
   "kind": "market",
   "orderable": true,
   "url": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch?utm_source=gadgets.sh&utm_medium=referral&utm_campaign=sensor-watch-lite&utm_content=api",
   "note": "Sold through Crowd Supply rather than the maker’s own shop."
  }
 ],
 "specs": [
  {
   "group": "Core hardware",
   "rows": [
    {
     "label": "Processor",
     "value": "ARM Cortex-M0+ up to 32 MHz · 256 KB flash with up to 8 KB EEPROM emulation · 32 KB RAM with full retention in standby",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    },
    {
     "label": "Display",
     "value": "Drives the original ten-digit segment LCD plus five indicator segments",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    },
    {
     "label": "Radio",
     "value": "None",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    },
    {
     "label": "Power",
     "value": "The watch battery; a 32.768 kHz crystal drives the real-time clock",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    }
   ]
  },
  {
   "group": "Details from the project page",
   "rows": [
    {
     "label": "Timekeeping",
     "value": "32.768 kHz crystal for real-time clock with alarm support",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    },
    {
     "label": "Backlight",
     "value": "Red and green PWM-able LED backlight",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    },
    {
     "label": "Sensors",
     "value": "On-board temperature sensor",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    },
    {
     "label": "Programming",
     "value": "USB Micro-B connector and a reset button with a double-tap UF2 bootloader",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    },
    {
     "label": "Buttons",
     "value": "Edge-plated contacts for three interrupt-capable buttons",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    },
    {
     "label": "Expansion",
     "value": "A pad for a piezo buzzer (needs light soldering) and two interrupt-capable digital inputs on test points",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    },
    {
     "label": "Relation to the Pro",
     "value": "The Lite is the current board; the original Sensor Watch is marked no longer available",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    }
   ]
  },
  {
   "group": "Buying",
   "rows": [
    {
     "label": "Price",
     "value": "US$39 on Crowd Supply",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    },
    {
     "label": "Availability",
     "value": "In stock on the day of review",
     "source": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
    }
   ]
  }
 ],
 "docs": [
  {
   "label": "Crowd Supply project page",
   "url": "https://www.crowdsupply.com/oddly-specific-objects/sensor-watch"
  },
  {
   "label": "Crowd Supply",
   "url": "https://www.crowdsupply.com"
  }
 ],
 "blueprint": {
  "openness": "open-hardware",
  "opennessLabel": "Open hardware",
  "summary": "Full KiCad schematic, PCB layout and gerbers for the Sensor Watch Lite mainboard (rev OSO-SWAT-B1) are public in the shared Sensor-Watch repo, per the repo's own hardware table.",
  "files": [
   {
    "kind": "schematic",
    "label": "Sensorwatch Lite mainboard (OSO-SWAT-B1) KiCad schematic",
    "url": "https://github.com/joeycastillo/Sensor-Watch/blob/main/PCB/Main%20Boards/OSO-SWAT-B1/OSO-SWAT-B1.kicad_sch",
    "format": "KiCad"
   },
   {
    "kind": "pcb",
    "label": "Sensorwatch Lite mainboard (OSO-SWAT-B1) KiCad PCB layout",
    "url": "https://github.com/joeycastillo/Sensor-Watch/blob/main/PCB/Main%20Boards/OSO-SWAT-B1/OSO-SWAT-B1.kicad_pcb",
    "format": "KiCad"
   },
   {
    "kind": "gerbers",
    "label": "Sensorwatch Lite fab package (rev -03)",
    "url": "https://github.com/joeycastillo/Sensor-Watch/blob/main/PCB/Main%20Boards/OSO-SWAT-B1/OSO-SWAT-B1-03.zip",
    "format": "ZIP"
   }
  ],
  "repos": [
   {
    "url": "https://github.com/joeycastillo/Sensor-Watch",
    "role": "hardware",
    "official": true,
    "license": null,
    "stars": 2078,
    "pushed": "2026-04-08"
   }
  ],
  "parts": [
   {
    "part": "Microchip SAM L22 (ATSAML22)",
    "role": "MCU + segment-LCD controller",
    "datasheet": "https://ww1.microchip.com/downloads/en/DeviceDoc/SAM-L22-Family-Data-Sheet-DS60001465B.pdf"
   }
  ],
  "notes": "Crowd Supply's Sensor Watch Lite page links github.com/joeycastillo/Sensor-Watch. The repo README's own 'Hardware Schematics and PCBs' table explicitly maps 'Sensorwatch Lite' (RED) to board OSO-SWAT-B1 -- distinct from plain 'Sensorwatch' (GREEN, OSO-SWAT-A1) and 'Sensorwatch Pro' (OSO-SWAT-C1, added later -- see that entry). Confirmed by reading the README table directly rather than assuming a folder name. Repo license: GitHub reports NOASSERTION (LICENSE.md has custom, non-standard text).",
  "checked": "2026-09-27"
 },
 "sourceFiles": {
  "kicad": [
   {
    "label": "Sensorwatch Lite mainboard (OSO-SWAT-B1) KiCad schematic",
    "repo": "joeycastillo/Sensor-Watch",
    "folder": "https://github.com/joeycastillo/Sensor-Watch/tree/main/PCB/Main%20Boards/OSO-SWAT-B1",
    "project": "https://raw.githubusercontent.com/joeycastillo/Sensor-Watch/main/PCB/Main%20Boards/OSO-SWAT-B1/OSO-SWAT-B1.kicad_pro",
    "schematics": [
     "https://raw.githubusercontent.com/joeycastillo/Sensor-Watch/main/PCB/Main%20Boards/OSO-SWAT-B1/OSO-SWAT-B1.kicad_sch"
    ],
    "boards": [
     "https://raw.githubusercontent.com/joeycastillo/Sensor-Watch/main/PCB/Main%20Boards/OSO-SWAT-B1/OSO-SWAT-B1.kicad_pcb"
    ]
   },
   {
    "label": "OSO SWAT C1",
    "repo": "joeycastillo/Sensor-Watch",
    "folder": "https://github.com/joeycastillo/Sensor-Watch/tree/main/PCB/Main%20Boards/OSO-SWAT-C1",
    "project": "https://raw.githubusercontent.com/joeycastillo/Sensor-Watch/main/PCB/Main%20Boards/OSO-SWAT-C1/OSO-SWAT-C1-rounded.kicad_pro",
    "schematics": [
     "https://raw.githubusercontent.com/joeycastillo/Sensor-Watch/main/PCB/Main%20Boards/OSO-SWAT-C1/OSO-SWAT-C1.kicad_sch"
    ],
    "boards": [
     "https://raw.githubusercontent.com/joeycastillo/Sensor-Watch/main/PCB/Main%20Boards/OSO-SWAT-C1/OSO-SWAT-C1-rounded.kicad_pcb",
     "https://raw.githubusercontent.com/joeycastillo/Sensor-Watch/main/PCB/Main%20Boards/OSO-SWAT-C1/OSO-SWAT-C1.kicad_pcb"
    ]
   },
   {
    "label": "OSO SWAB B1 00 Sensor Watch Accelerometer",
    "repo": "joeycastillo/Sensor-Watch",
    "folder": "https://github.com/joeycastillo/Sensor-Watch/tree/main/PCB/Sensor%20Boards/Kicad/OSO-SWAB-B1-00%20Sensor%20Watch%20Accelerometer",
    "project": "https://raw.githubusercontent.com/joeycastillo/Sensor-Watch/main/PCB/Sensor%20Boards/Kicad/OSO-SWAB-B1-00%20Sensor%20Watch%20Accelerometer/OSO-SWAB-B1-00%20Sensor%20Watch%20Accelerometer.kicad_pro",
    "schematics": [
     "https://raw.githubusercontent.com/joeycastillo/Sensor-Watch/main/PCB/Sensor%20Boards/Kicad/OSO-SWAB-B1-00%20Sensor%20Watch%20Accelerometer/OSO-SWAB-B1-00%20Sensor%20Watch%20Accelerometer.kicad_sch"
    ],
    "boards": [
     "https://raw.githubusercontent.com/joeycastillo/Sensor-Watch/main/PCB/Sensor%20Boards/Kicad/OSO-SWAB-B1-00%20Sensor%20Watch%20Accelerometer/OSO-SWAB-B1-00%20Sensor%20Watch%20Accelerometer.kicad_pcb"
    ]
   }
  ],
  "models": []
 },
 "firmware": [
  {
   "name": "Movement",
   "url": "https://github.com/joeycastillo/Sensor-Watch",
   "tag": "Watch OS",
   "description": "Community watch faces, accelerometer monitors, and sensor logger complications for the classic Casio F-91W."
  }
 ],
 "chips": []
}