Power up your audio world with ADA4254 and ATmega2560
Hear every note in clarity
Published Feb 14, 2024
Click board™
GainAMP 3 Click
Dev. board
Arduino Mega 2560 Rev3
Compiler
NECTO Studio
MCU
ATmega2560
Take control of your audio with our programmable gain instrumentation amplifier, offering precise gain adjustment for optimal sound customization
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Hardware Overview
How does it work?
GainAMP 3 Click is based on the ADA4254, a zero drift, high voltage, programmable gain instrumentation amplifier (PGIA) designed for process control and industrial applications from Analog Devices. It accurately measures sensors, voltages, and currents with wide dynamic ranges and provides safety information about what is being measured. It features 12 binary weighted gains ranging from 1/16V/V to 128V/V and three scaling gain options of 1V/V, 1.25V/V, and 1.375V/V, resulting in 36 possible gain settings. Its zero-drift amplifier topology self-calibrates DC errors and low-frequency noise, achieving excellent DC precision over the entire specified temperature range, maximizing dynamic range, and significantly reducing calibration requirements in many applications.
The ADA4254 communicates with MCU using the standard SPI serial interface with a maximum frequency of 5MHz, supporting the most common SPI mode, SPI Mode 0. It comes with a 4-channel input multiplexer providing ±60V protection to the high impedance inputs of the amplifier and an excitation current source output available to bias sensors such as resistance temperature detectors (RTDs). In addition to these channels located on the onboard 9-pole connector, the ADA4254 also has a differential output stage and output excitation current channels. A differential output stage lets the device connect to high-precision ADCs directly. When making such a connection, it is recommended to use a low-pass filter before a connection to the ADCs to minimize noise
and aliasing. A software configurable excitation current outputs can be used to excite external circuitry, such as resistive bridges or RTD sensors, and be programmed to a value from 100μA to 1.5mA in increments of 100μA. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. In addition to choosing the logic voltage level using a jumper labeled DIGI, selecting the amplifier's supply voltage using the AN jumper by positioning SMD jumpers to an appropriate position is possible. This way, both 3.3V and 5V capable MCUs can 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.
Features overview
Development board
Arduino Mega 2560 is a robust microcontroller platform built around the ATmega 2560 chip. It has extensive capabilities and boasts 54 digital input/output pins, including 15 PWM outputs, 16 analog inputs, and 4 UARTs. With a 16MHz crystal
oscillator ensuring precise timing, it offers seamless connectivity via USB, a convenient power jack, an ICSP header, and a reset button. This all-inclusive board simplifies microcontroller projects; connect it to your computer via USB or power it up
using an AC-to-DC adapter or battery. Notably, the Mega 2560 maintains compatibility with a wide range of shields crafted for the Uno, Duemilanove, or Diecimila boards, ensuring versatility and ease of integration.
Microcontroller Overview
MCU Card / MCU
Architecture
AVR
MCU Memory (KB)
256
Silicon Vendor
Microchip
Pin count
100
RAM (Bytes)
8192
You complete me!
Accessories
Click Shield for Arduino Mega comes equipped with four mikroBUS™ sockets, with two in the form of a Shuttle connector, allowing all the Click board™ devices to be interfaced with the Arduino Mega board with no effort. Featuring an AVR 8-bit microcontroller with advanced RISC architecture, 54 digital I/O pins, and Arduino™ compatibility, the Arduino Mega board offers limitless possibilities for prototyping and creating diverse applications. This board is controlled and powered conveniently through a USB connection to program and debug the Arduino Mega board efficiently out of the box, with an additional USB cable connected to the USB B port on the board. Simplify your project development with the integrated ATmega16U2 programmer and unleash creativity using the extensive I/O options and expansion capabilities. There are eight switches, which you can use as inputs, and eight LEDs, which can be used as outputs of the MEGA2560. In addition, the shield features the MCP1501, a high-precision buffered voltage reference from Microchip. This reference is selected by default over the EXT REF jumper at the bottom of the board. You can choose an external one, as you would usually do with an Arduino Mega board. There is also a GND hook for testing purposes. Four additional LEDs are PWR, LED (standard pin D13), RX, and TX LEDs connected to UART1 (mikroBUS™ 1 socket). This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the Arduino Mega board with Click Shield for Arduino Mega, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Arduino Mega 2560 Rev3 as your development board.
Track your results in real time
Application Output
1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.
2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.
3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.
Software Support
Library Description
This library contains API for GainAMP 3 Click driver.
Key functions:
gainamp3_write_register- This function writes a data byte to the selected register by using SPI serial interface.gainamp3_set_amplifier_gain- This function sets the amplifier gain level.gainamp3_set_input_channel- This function sets the input channel.
Open Source
Code example
The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.
/*!
* @file main.c
* @brief GainAMP3 Click example
*
* # Description
* This example demonstrates the use of GainAMP 3 click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs the click default configuration which
* verifies the communication and sets active the input channel 1.
*
* ## Application Task
* Changes the amplifier gain level every 3 seconds and displays the gain value on the USB UART.
*
* @note
* VDDH should be within the range from +5V to +30V.
* VSSH should be within the range from -5V to -30V.
* Input channels should be within the range from GND to VCC selected by the VCC_SEL SMD jumpers.
* Gain * Input voltage must not exceed VCC voltage.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "gainamp3.h"
static gainamp3_t gainamp3;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
gainamp3_cfg_t gainamp3_cfg; /**< Click config object. */
/**
* Logger initialization.
* Default baud rate: 115200
* Default log level: LOG_LEVEL_DEBUG
* @note If USB_UART_RX and USB_UART_TX
* are defined as HAL_PIN_NC, you will
* need to define them manually for log to work.
* See @b LOG_MAP_USB_UART macro definition for detailed explanation.
*/
LOG_MAP_USB_UART( log_cfg );
log_init( &logger, &log_cfg );
log_info( &logger, " Application Init " );
// Click initialization.
gainamp3_cfg_setup( &gainamp3_cfg );
GAINAMP3_MAP_MIKROBUS( gainamp3_cfg, MIKROBUS_1 );
err_t init_flag = gainamp3_init( &gainamp3, &gainamp3_cfg );
if ( SPI_MASTER_ERROR == init_flag )
{
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
init_flag = gainamp3_default_cfg ( &gainamp3 );
if ( GAINAMP3_ERROR == init_flag )
{
log_error( &logger, " Default Config Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
for ( uint8_t cnt = GAINAMP3_GAIN_1_OVER_16; cnt <= GAINAMP3_GAIN_128; cnt++ )
{
gainamp3_set_amplifier_gain ( &gainamp3, cnt );
log_printf( &logger, " Amplifier gain set to " );
float gain = ( 1 << cnt ) / 16.0;
if ( gain < 1.0 )
{
log_printf( &logger, "1/%u\r\n", ( uint16_t ) ( 1.0 / gain ) );
}
else
{
log_printf( &logger, "%u\r\n", ( uint16_t ) gain );
}
Delay_ms( 3000 );
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
Additional Support
Resources
Category:Amplifier
