Coral Environmental Sensor Board

TheCoral Environmental Sensor Board is an expansion board that adds temperature, light, and humidity sensing capabilities to a Coral Dev Board or Raspberry Pi microcomputer that can be used for IoT applications. It is also possible to further expand the measurement functionality by adding other sensors using Grove connectors.

Key features:

• Built-in security element allows you to work with Google Cloud IOT Core.
• It has four built-in Grove connectors that allow you to add additional sensors.
• Compatible with Coral and Raspberry Pi boards. The 40-pin connector plugs into a Coral Dev Board, Dev Board Mini, or any Raspberry Pi board (the environmental sensor board contains an EEPROM for identification on Raspberry Pi boards).

General Specifications:

Display: OLED display 128x32
Crypto chip: Security Microchip ECC608 with Google keys
Humidity: HDC2010 humidity sensor
Lighting: OPT3002 ambient light sensor
Pressure: BMP280 barometric pressure sensor
Connections: Four Grove connectors, UART, I2C, PWM
Power supply: 3,3/5В

Sensor characteristics:

Texas Instruments HDC2010 humidity and temperature sensor:
● Humidity range/accuracy: 0-100% ± 2% (typical)
Temperature range/accuracy: -40 to +125 °C (functional) ± 0.2 °C (typical) I2C address: 0x40

Texas Instruments OPT3002 ambient light sensor:
● Optical spectrum: 300-1000 nm
● Measurement range: 1.2-10 mW/cm2 I2C address: 0x45

Bosch Sensortec BMP280 barometric pressure sensor:
● Operating range: 300-1100 hPa
● Absolute accuracy (at 0-65 °C): ± 1 hPa
● Relative accuracy (at 700-900 hPa; 25-40 °C): ± 0.12 hPa (typical) I2C address: 0x76

OLED display
The 128x32 OLED display is controlled by the SSD1306 control chip connected to the SPI interface.

Crypto processor
The board contains a crypto processor (ATECC608A) with EEPROM that can store up to 16 keys (256-bit), certificates, or other data. While this chip provides a number of cryptographic functions, it is primarily included to provide secure key generation and management for secure authentication with the device.

The factory settings for the Environmental Sensor Board include one Google key (private key, public key, and certificate) right out of the box. This key slot is reusable, just like the rest of the memory.

Grove interfaces:

The Grove connectors provide easy access to the PWM, UART, and I2C pins from the main board, as well as the built-in analog-to-digital converter (ADC). The VDD_A pin of the Grove analog connector can be powered from the 5V or 3.3V power bus using jumpers labeled ANALOG VDD JUMPER in the figure.

Overall dimensions: 65mm x 30mm x 18.5mm

Weight: 0.014 kg