Power up your audio world with ADA4254 and PIC18LF47K40
Hear every note in clarity
Published May 14, 2023
Click board™
GainAMP 3 Click
Dev. board
EasyPIC v8
Compiler
NECTO Studio
MCU
PIC18LF47K40
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
EasyPIC v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports many high pin count 8-bit PIC microcontrollers from Microchip, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, EasyPIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any
circumstances at any time. Each part of the EasyPIC v8 development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector.
Communication options such as USB-UART, USB DEVICE, and CAN are also included, including the well-established mikroBUS™ standard, two display options (graphical and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from the smallest PIC MCU devices with only eight up to forty pins. EasyPIC v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.
Microcontroller Overview
MCU Card / MCU
Architecture
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
40
RAM (Bytes)
3728
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 EasyPIC v8 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 ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
}
}
int main ( void )
{
/* Do not remove this line or clock might not be set correctly. */
#ifdef PREINIT_SUPPORTED
preinit();
#endif
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END
