Ambient 18 Click is a compact add-on board used to sense the amount of the present ambient light. This board features the BH1680FVC, an analog current-output ambient light sensor from Rohm Semiconductor. The BH1680FVC can detect a wide range of illuminance up to 10klx and provides excellent responsivity close to the human eyes' response. Besides, it is also characterized by low sensitivity variation across various light sources, a built-in shutdown function, and the ability to process the output signal in analog or digital form. This Click board™ is the most suitable for obtaining ambient light data for adjusting brightness in applications that require power saving and better visibility.

Ambient 18 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

Ambient 18 Click as its foundation uses the BH1680FVC, an analog current-output ambient light sensor from Rohm Semiconductor. It is composed of photodiodes, amplifiers, and current mirror circuits and can detect a wide range of illuminance up to 10klx, providing excellent responsivity close to the human eyes' response. It has stable performance over a wide temperature, voltage range, and a built-in shutdown function. It is characterized by good output linearity across a wide illumination range and low sensitivity variation across various light sources suitable to sense the amount of the present ambient light.

It also has four configurable modes of operation, shutdown mode associated with three gain modes: high-gain mode, medium-gain mode, and low-gain mode. The desired gain mode is selected through CS and PWM pins of the mikroBUS™ socket labeled as GC1 and GC2.

The output of the BH1680FVC can be converted to a digital value using MCP3221, a successive approximation A/D converter with a 12-bit resolution from Microchip, using a 2-wire I2C compatible interface, or can be sent directly to an analog pin of the mikroBUS™ socket labeled as AN. Selection can be performed by onboard SMD jumper labeled as ADC SEL to an appropriate position marked as AN and I2C.

The MCP3221 provides one single-ended input with low power consumption, a low maximum conversion current, and a Standby current of 250μA and 1μA, respectively. Data can be transferred at rates of up to 100kbit/s in the Standard and 400kbit/s in the Fast Mode. Also, maximum sample rates of 22.3kSPS with the MCP3221 are possible in a Continuous-Conversion Mode with a clock rate of 400kHz.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VIO SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use the communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.

• Interface: Analog, GPIO, I²C
• Compatibility: mikroBUS™
• Dimensions: 28.6 x 25.4mm
• Input Voltage: 3.3V or 5V
• Maximum Output Current: 7.5mA
• Peak Wavelength: 530nm
• Operating Temperature Range: Min. -40°C, Typ. +25°C, Max. +85°C

• Schematic
• MCP3221 Datasheet
• BH1680FVC Datasheet
• mikroSDK
• GitHub