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Single-unit price: $39.99 + shipping

Campaign scheduled end date: Wed, 04 Sep 2019 11:56:46 PDT

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Backers: 6

Target icon campaign show

Target: 20

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Funded: 21

Product Details



Brand / Manufacturer

J&J Studios

Manufacturer Part #


Product Description

alt text datum-Light

URI command syntax. JSON encapsulated data packets.

The ideal light sensor for your next IoT or robotics project.

  • datum
    1. a piece of information
    2. a fixed starting point of a scale or operation
  • light
    1. the natural agent that stimulates sight and makes things visible


  • Atmel SAMD21G18 microcontroller
  • Broadcom APDS-9960 light sensor
  • Onboard EEPROM settings storage
  • URI style command interface
  • JSON formatted data packets
  • Globally unique 64 bit UUID
  • UF2 Bootloader
  • Mounting holes in all four corners
  • 1.0” x 1.75” (25.4 mm x 44.4 mm)

The datum-Light sensor combines the same SAMD21G18 microcontroller used on the Arduino Zero with the APDS-9960 light sensor from Broadcom to create the simplest, easiest to use light sensor for your application.

The datum-Light sensor emulates a serial port over a USB connection, presents the information and data stored on it in a JSON formatted packet, and processes URI style commands to change and retrieve its settings. The datum-Light sensor fills the gap between a LEGO® Mindstorms® sensor and a breakout board.

Control the behavior of the sensor by using URI style commands right from your favorite terminal program. Want to set the report rate to 10 Hz and send the reports automatically? The following command does just that.

set /config?reportRate=10&automaticReporting=true

Not sure what the settings for the datum-Light sensor were? The following command will retrieve them in a JSON formatted data packet.

get /sensor/light/config

  "color": {
    "enabled": true,
    "units": "counts",
    "gain": 16,
    "integrationCycles": 64,
    "filterType": "mean",
    "sampleRate": 20,
    "dataRate": 10
  "proximity": {
    "enabled": true,
    "units": "counts",
    "gain": 1,
    "LEDstrength": "25 mA",
    "filterType": "mean",
    "sampleRate": 20,
    "dataRate": 10

The data from the datum-Light sensor is also encapsulated in a JSON formatted packet. This results in human readable text that is still easy to parse with your favorite programming language. An example of the output is shown below.

  "timestamp": 84.804,
  "color": {
    "time": [84.675, 84.775],
    "ambient": [40, 40],
    "red": [19, 19],
    "green": [19, 19],
    "blue": [18, 18]
  "proximity": {
    "time": [84.678, 84.778],
    "proximity": [7, 7]

The datum-Light sensor can do much more than just collect the data. The measurement units can be customized to suit your application. Light and proximity data can be returned in counts or normalized units. The datum-Light sensor does all the calculations for you.

It can also apply filters such as min, mix, mean, and RMS to the data stream. This truly makes the datum-Light sensor a smart sensor that goes far beyond what a breakout board can do. The datum-Light sensor is also programmed with an Arduino compatible bootloader allowing full customization of the firmware.

alt text alt text

The datum-Light sensor is just one of the sensors in the datum line currently available. The other sensors, datum-Weather, datum-Light, and datum-IMU all feature the same easy to use, text based interface. More information on the full spectrum of sensors is available here.

Why GroupGets?

J&J Studios is focused on making it easier for students and hobbyists to integrate sensors into their projects. For someone new to electronics a breadboard, jumper wires, breakout boards, and header pins can be intimidating. Many people are already familiar with a URI syntax for getting and setting parameters and receiving data in JSON encapsulated packets. Therefore our products focus on translating the language a sensor speaks into that more familiar format. J&J Studios is breaking the barrier between a LEGO® Mindstorms® sensor and a breakout board.

External Links

Manufacturer product page

Purchase Information

Unit Deliverable

One unit of the datum-Light sensor.

Unit Price


Campaign Part #



Campaign funded, scheduled end date: Wed, 04 Sep 2019 11:56:46 PDT

Factory Lead Time

7 Days

Campaign discussion forums are intended for questions about the product such as specifications or to share ideas about applications. The campaign initiator or GroupGets may also send out important one-to-many updates on this channel. This is not the place for individual technical support inquiries. For help or questions about an order, please log a ticket here: Support

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