DAQ 3 Click

How does it work?

DAQ 3 Click as its foundation uses the ADAQ4003, a fast and precise system-in-package DAQ signal chain solution from Analog Devices. This μModule combines multiple standard signal processing and conditioning blocks into a single device containing a high bandwidth fully differential ADC driver, a low noise reference buffer, and an 18-bit SAR ADC along with selectable gain options. It can convert 2,000,000 samples per second (2 MSPS), achieving a high degree of specified accuracy. The ADAQ4003 also has a valid first conversion after being powered down for long periods to reduce the power consumed in applications where the ADC does not convert constantly.

The ADAQ4003 requires a supply voltage of 1.8V to work regularly. Therefore, a small regulating LDO, the ADP151 from Analog Devices, provides a 1.8V out of mikroBUS™ rails. In combination with LT3032, dual low noise positive and negative low dropout voltage linear regulator, it can generate regulated ±15 V positive and negative rails for any additional signal conditioning. This Click board™ also includes the LT6656, a precise voltage regulator that provides low noise and low drop out voltage reference of 4.096V. This feature intends to optimally drive the dynamic input impedance of the SAR ADC reference node.

DAQ 3 Click communicates with MCU using the 16-bit SPI serial interface compatible with standard SPI, QSPI™, MICROWIRE™, and digital signal processors (DSPs). The ADAQ4003 also has a Turbo mode allowing a slower SPI clock rate, making interfacing simpler. Turbo mode activates by writing to the configuration register and replaces the busy indicator feature when enabled. The ADAQ4003 can achieve the maximum throughput of 2 MSPS only with enabled Turbo mode and a minimum clock rate of 75 MHz.

An additional feature of this Click board™ represents specific settings related to a fully differential ADC driver like Power-Down Reference Buffer and Amplifier labeled as DRE and DAM routed on the RST and AN pins of the mikroBUS™ socket. Also, the ADC driver has one power mode pin labeled as MOD and routed on the PWM pin of the mikroBUS™ socket, which enables the full performance of the driver with this pin sets to its high logic state. On the other hand, the ADAQ4003 also uses INT pin as an interrupt, indicating that the conversion result is available on the SDO line of the SPI interface.

This Click board™ also comes with the jumpers labeled from JP2-JP8 required to achieve optimized performance with selectable gain options of 0.454, 0.909, 1, or 1.9. With jumpers labeled as JP4 and JP7 populated on the board, the default gain of the ADAQ4003 is set to 1. For more information about the correct jumper configuration when selecting gain, please consult the attached datasheet.

DAQ 3 Click possesses two SMA connectors labeled as IN- and IN+ that provide low noise analog signal sources. These inputs are fed and buffered with the LTC6373, a precision instrumentation amplifier with fully differential outputs that achieves excellent offset voltage, gain error, gain drift, and gain non-linearity. The user can easily program the gain to one of seven available settings through 3 slide switches labeled as GAIN SEL.

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 properly use the SPI communication lines. 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 DAQ 3 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Reference Amplifier Power-Down Control	DAM	1	AN	PWM	16	MOD	ADC Driver Power Mode Selection
Reference Buffer Power-Down Control	DRE	2	RST	INT	15	INT	Interrupt / Busy Indicator
SPI Chip Select	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
SPI Data OUT	SDO	5	MISO	SCL	12	NC
SPI Data IN	SDI	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

DAQ 3 Click electrical specifications

Software Support

We provide a library for the DAQ 3 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 DAQ 3 Click driver.

Key functions:

• float daq3_get_voltage ( daq3_t *ctx ); - DAQ 3 get voltage function.
• int32_t daq3_get_conversion_result ( daq3_t *ctx, daq3_reg_cfg_t cfg_data ); - DAQ 3 get conversion result function.
• err_t daq3_generic_read ( daq3_t *ctx, uint8_t reg, uint8_t *data_out ); - DAQ 3 data reading function.

Examples description

The demo application reads ADC value, calculate and display voltage ( mV ).

The demo application is composed of two sections :

void application_task ( void ) {   
    float voltage = daq3_get_voltage( &daq3 );
    log_printf( &logger, "   Voltage : %.3f mV       rn", voltage );
    log_printf( &logger, "---------------------------rn" );
    Delay_ms( 2000 );
}

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.Daq3

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

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.