Optimize performance with accurate current sensing using AD8616 and ATmega328P
The future of current monitoring!
Published Feb 14, 2024
Click board™
Ammeter Click
Dev. board
Arduino UNO Rev3
Compiler
NECTO Studio
MCU
ATmega328P
Our advanced ammeter provides real-time measurement of electric currents, empowering you with instant and accurate data to optimize efficiency and ensure safe operations
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Hardware Overview
How does it work?
Ammeter Click is based on the AD8616, a precision 20MHz CMOS rail-to-rail input/output operational amplifier from Analog Devices. It is a dual single-supply amplifier featuring very low offset voltage, wide signal bandwidth, and low input voltage and current noise. The AD8616 uses a patented trimming technique that achieves superior precision without laser trimming. Two onboard screw terminals labeled probe+ and probe-are bringing in the current, which then passes through a shunt resistor. A voltage proportional to the strength of the current is generated across the resistor, which is then processed in the operational
amplifier. The voltage amplified through the AD8616 can be directly monitored through the AN pin of the mikroBUS™ socket. One of the main features of the Ammeter Click is the MCP3201, a 12-bit A/D converter with the SPI serial interface from Microchip. This A/D converter has a sampling rate of up to 100ksps and has an onboard sample and hold circuitry. It provides a single pseudo-differential input with maximum differential nonlinearity at ±1LSB. The AD8616 fed the amplified current to this A/D convertor, which gets the 2.048V reference voltage from the MAX6106, a micropower low-dropout high-output-current
voltage reference from Analog Devices. The MCP3201 outputs digital value through the mikroBUS™ socket SPI interface to the host MCU. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the PWR SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this 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 UNO is a versatile microcontroller board built around the ATmega328P chip. It offers extensive connectivity options for various projects, featuring 14 digital input/output pins, six of which are PWM-capable, along with six analog inputs. Its core components include a 16MHz ceramic resonator, a USB connection, a power jack, an
ICSP header, and a reset button, providing everything necessary to power and program the board. The Uno is ready to go, whether connected to a computer via USB or powered by an AC-to-DC adapter or battery. As the first USB Arduino board, it serves as the benchmark for the Arduino platform, with "Uno" symbolizing its status as the
first in a series. This name choice, meaning "one" in Italian, commemorates the launch of Arduino Software (IDE) 1.0. Initially introduced alongside version 1.0 of the Arduino Software (IDE), the Uno has since become the foundational model for subsequent Arduino releases, embodying the platform's evolution.
Microcontroller Overview
MCU Card / MCU
Architecture
AVR
MCU Memory (KB)
32
Silicon Vendor
Microchip
Pin count
28
RAM (Bytes)
2048
You complete me!
Accessories
Click Shield for Arduino UNO has two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the Arduino UNO board without effort. The Arduino Uno, a microcontroller board based on the ATmega328P, provides an affordable and flexible way for users to try out new concepts and build prototypes with the ATmega328P microcontroller from various combinations of performance, power consumption, and features. The Arduino Uno has 14 digital input/output pins (of which six can be used as PWM outputs), six analog inputs, a 16 MHz ceramic resonator (CSTCE16M0V53-R0), a USB connection, a power jack, an ICSP header, and reset button. Most of the ATmega328P microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. 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 UNO board with our Click Shield for Arduino UNO, 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 UNO 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 Ammeter Click driver.
Key functions:
ammeter_amperage- Function is used to measure amperage of a power consumer connected to the Ammeter Click
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
* \brief Ammeter Click example
*
* # Description
* Demo app measures and displays current by using Ammeter Click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initalizes SPI, LOG and Click drivers.
*
* ## Application Task
* This is an example that shows the capabilities of the Ammeter Click by
* measuring amperage in miliampers. Ammeter Click board can be used to saftly
* measure current up to 1A both AC and DC, in the case of AC,
* for peak to peak value.
*
* *note:*
* It is important to notice that this Click board has its' own electronic
* circuit, and may not be powered from the same source which we are measuring.
* Result will not be correct in that case.
*
* \author Jovan Stajkovic
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "ammeter.h"
// ------------------------------------------------------------------ VARIABLES
static ammeter_t ammeter;
static log_t logger;
static float amperage;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
ammeter_cfg_t cfg;
/**
* 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.
ammeter_cfg_setup( &cfg );
AMMETER_MAP_MIKROBUS( cfg, MIKROBUS_1 );
ammeter_init( &ammeter, &cfg );
log_printf( &logger, "-----------------------\r\n" );
log_printf( &logger, " Ammeter Click \r\n" );
log_printf( &logger, "-----------------------\r\n" );
}
void application_task ( void )
{
amperage = ammeter_amperage( &ammeter );
log_printf( &logger, " Current: %.2f mA\r\n", amperage );
log_printf( &logger, "-----------------------\r\n" );
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
Additional Support
Resources
Category:Current sensor
