Library Description

Initializes and defines SPI bus driver and driver functions witch offer a choice to convert analog input voltage to 24-bit digital output value. Functions also offer a choice to choose witch channels we want use for positive and negative analog input by writting in configurations registers. Functions can read converted data in two modes, single read, where we must be sure that converting is done, or continuous read mode, where we only continuously read converted data without writting anything on SPI, not even an data register address. Library also defines commands witch help us to configure registers. Check documentation for more details.

Key functions :

void adc6_writeReg( const uint8_t register_address, const uint32_t transfer_data ) - Function writes data to determined register.

uint32_t adc6_readReg( const uint8_t register_address ) - Function reads data from determined register.

uint32_t adc6_continuousReadData( void ) - Function continuously reads data from Data register without writting anything on SPI.

uint32_t adc6_getADCData( const uint8_t mode ) - Function gets data from Data register in two possible modes. In single read mode first checks ready bit, and when conversion is done (data is ready) reads data from register. In continuous read mode only reads data without writting anything on SPI bus.

Examples Description

The application is composed of three sections :

• System Initialization - Initializes peripherals and pins.
• Application Initialization - Initializes SPI bus driver and sets configuration witch enables channel 0, puts AIN0 on positive analog input and AIN1 on negative analog input, enables internal reference voltage (approximately 2.65V (AVDD = 3.3V)), and also enables bipolar operation mode and puts device on full power mode. When the ADC is configured for unipolar operation, the output code is natural (straight) binary with a zero differential input voltage resulting in a code of 0x00000000, a midscale voltage resulting in a code of 0x00800000, and a full-scale input voltage resulting in a code of 0x00FFFFFF. When the ADC is configured for bipolar operation, the output code is offset binary with a negative full-scale voltage resulting in a code of 0x00000000, a zero differential input voltage resulting in a code of 0x00800000, and a positive full-scale input voltage resulting in a code of 0x00FFFFFF.
• Application Task - (code snippet) - Gets 24-bit converted data in single read mode and logs data on USB UART. Repeats operation every 500 ms.

void applicationTask()
{
 adc_value = adc6_getADCData( _ADC6_SINGLE_GET_DATA_MODE );
 LongWordToStr( adc_value, text );
 if ( tmp )
 {
 mikrobus_logWrite( "** The ADC value is: **", _LOG_LINE );
 tmp = 0;
 }
 mikrobus_logWrite( text, _LOG_LINE );

 Delay_ms( 500 );
}

Other mikroE Libraries used in the example:

• Conversions
• SPI
• UART

Additional notes and information

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. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.