Ambient 18 Click

How does it work?

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.

Specifications

Pinout diagram

This table shows how the pinout on Ambient 18 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Analog Signal	AN	1	AN	PWM	16	GC1	Gain Mode Control Signal 2
	NC	2	RST	INT	15	NC
Gain Mode Control Signal 1	GC1	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	SCL	I2C Clock
	NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Ambient 18 Click electrical specifications

Software Support

We provide a library for the Ambient 18 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for Ambient 18 Click driver.

Key functions

• ambient18_set_gain_mode This function sets the gain mode.

• ambient18_read_voltage This function reads raw ADC value and converts it to proportional voltage level.

• ambient18_voltage_to_lux This function calculates illuminance (lux) based on the voltage input.

Example Description

This example demonstrates the use of Ambient 18 Click board™ by measuring and displaying the illuminance value in Lux.

 void application_task ( void ) 
 { 
     float voltage = 0; 
     if ( AMBIENT18_OK == ambient18_read_voltage ( &ambient18, &voltage ) )  
     { 
         log_printf( &logger, " Illuminance : %ld Luxrnn", ambient18_voltage_to_lux( &ambient18, voltage ) ); 
         Delay_ms( 1000 ); 
     } 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Ambient18

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MikroElektronika compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MikroElektronika Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.