Optimize performance with accurate current sensing using AD8616 and PIC18F57Q43
The future of current monitoring!
Published Feb 13, 2024
Click board™
Ammeter Click
Dev. board
Curiosity Nano with PIC18F57Q43
Compiler
NECTO Studio
MCU
PIC18F57Q43
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
PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive
mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI
GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.
Microcontroller Overview
MCU Card / MCU
Architecture
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
48
RAM (Bytes)
8196
You complete me!
Accessories
Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.
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 Curiosity Nano with PIC18F57Q43 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
