Digital Ambient Light sensor:

The digital ambient light sensor is used to control the brightness of the electronic devices according to the level of light in the surroundings. Ambient light sensors are used in a wide variety of applications that require precise measurement of light as perceived by the human eye since they have a specialized filter that mimics the human eye. It is mostly used in smartphones, smartwatches, and other wearable electronics.

Description of OPT4001:

OPT4001 measures the ambient light that illuminates the device. This device measures light with a spectral response very closely matched to the human eye, and with very good infrared rejection. Matching the sensor spectral response to that of the human eye response is vital because ambient light sensors are used to measure and help create ideal human lighting experiences.

The OPT4001 is designed for systems that require light level detection to enhance user experience and typically replace low-accuracy photodiodes diodes, photo-resistors, and other ambient light sensors with underwhelming human eye matching and near infra-red rejection.

Circuit Design:

This OPT4001 evaluation board consists of three parts:

• Flex Coupon board: It is a flex PCB that contains OPT4001 IC. This flex board is soldered onto a rigid coupon board for added stability.
• Rigid Coupon board: The rigid coupon board contains 8 pins which allow it to plug into a socket on the motherboard.
• Motherboard: The motherboard contains an MSP430 microcontroller and plugs into a PC through the provided USB cable.

To set up and test this board, first install OPT4001EVM GUI software on your computer. For further installation information please refer to OPT4001YMNEVM User's Guide by TI.

This board can be attached with smartwatches, health fitness bands, and smartphones. Embed the GUI software in the board using a computer and USB cable and use it with your devices. This will help in making your smart device friendly in different kinds of environments and light levels.

Schematic file:

I have uploaded the schematic file online on Inventhub. The schematic is split into three sections: connector, MSP430, and socket. A USB type C connector is used to interface with the PC. The MSP430 microcontroller allows the PC to interface with the OPT3004DTS through I2C. The coupon board containing the OPT4001 plugs into the motherboard through the socket. The OPTMBEVM(Motherboard) board provides easy access to the I2C, INT, VDD, and GND lines.

PCB file:

For fabrication, I have uploaded all my PCB files of the design on Inventhub. I can view the board in different layers and can focus on a specific layer of the board. Instead of visiting the manufacturer, I can send him this file, he can view or download it and can fabricate my board.

BOM file:

After fabrication, I need components to get finalized my board, for this, I have created a Bill of Material(BOM) of my components on Inventhub that contains the dimensions of all my components with footprints. I can also calculate the total cost of my project by clicking on the ‘Edit BOM’ and enabling the ‘Supply Chain’ button. Our total cost is $30. The component provider will only export that file in CSV format and can deliver the same components as I required for my design.

Applications:

Ambient light sensors are used in a wide variety of applications that require precise measurement of light as perceived by the human eye since they have a specialized filter that mimics the human eye. This OPT4001 evaluation board has wide applications like:

• Display backlight controls for
  • Smartwatch
  • Smart Phones
  • Wearable electronics
  • Health fitness bands

To get complete how-to and detailed information on the project design and implementation visit this link:

Complete Project link