Enable seamless integration of analog signals into digital systems with LTC1864 and PIC18F86K90
Decode the analog realm
Published Jun 01, 2023
Click board™
ADC 11 Click
Dev Board
Fusion for PIC v8
Compiler
NECTO Studio
MCU
PIC18F86K90
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Hardware Overview
How does it work?
ADC 11 Click is based on the LTC1864, a 16-bit successive approximation A/D converter with a sample-and-hold feature that operates on a single 5V supply from Analog Devices. The supply current, which can be only 850μA at 250ksps, drops at lower speeds because the LTC1864 automatically power-down between conversions. The high impedance analog input and the ability to operate with reduced spans down to 1V full scale allow direct connection to signal sources in many applications, eliminating the need for external gain stages.
Equipped with the 3-wire SPI serial interface and extremely high sample rate-to-power ratio, this Click board™ represents an ideal solution for compact, low-power, high-speed systems. ADC 11 click communicates with MCU through the simple 3-wire serial I/O compatible with industry-standard SPI interface. The LTC1864 has an internal conversion clock, so the clock rate does not affect the conversion. This fact allows the clock rate to run to 20MHz without concern for sample-and-hold droop at low clock frequencies or clocking the ADC too fast at high clock frequencies.
TThe data transfer requires only 16 clock cycles, minimizing the time necessary to transfer the data. The entire conversion can be transferred in only 800ns if the conversion clock runs at the maximum rate of 20MHz. This Click board™ can only be operated with a 5V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used as a reference for further development.
Features overview
Development board
Fusion for PIC v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different PIC, dsPIC, PIC24, and PIC32 MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. 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, Fusion for PIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any
circumstances at any time. Each part of the Fusion for PIC 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
HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet are also included, including the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options (graphical and character-based LCD). Fusion for PIC 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
Type
8th Generation
Architecture
PIC
MCU Memory (KB)
64
Silicon Vendor
Microchip
Pin count
80
RAM (Bytes)
3828
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Fusion for PIC v8 as your development board.
Track your results in real time
Application Output
After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.
Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.
In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".
The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.
Software Support
Library Description
This library contains API for ADC 11 Click driver.
Key functions:
adc11_cfg_setup- Config Object Initialization function.adc11_init- Initialization function.adc11_default_cfg- Initialization function.
Open Source
Code example
This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.
/*!
* @file main.c
* @brief Adc11 Click example
*
* # Description
* This library contains API for ADC 11 Click driver.
* The library contains drivers for measuring ADC values
* and for calculation voltage.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes SPI driver and triggers the built-in calibration.
*
* ## Application Task
* This is an example that demonstrates the use of the ADC 11 Click board.
* In this example, we monitor and display voltage [ V ].
* Results are being sent to the Usart Terminal, where you can track their changes.
* All data logs write on USB UART changes every 2 sec.
*
* @author Nenad Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "adc11.h"
static adc11_t adc11;
static log_t logger;
adc11_calibration_data_t avg_adc_data;
float voltage;
uint16_t adc_data;
void application_init ( void ) {
log_cfg_t log_cfg; /**< Logger config object. */
adc11_cfg_t adc11_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 );
// Click initialization.
adc11_cfg_setup( &adc11_cfg );
ADC11_MAP_MIKROBUS( adc11_cfg, MIKROBUS_1 );
err_t init_flag = adc11_init( &adc11, &adc11_cfg );
if ( init_flag == SPI_MASTER_ERROR ) {
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
log_printf( &logger, "---------------------------\r\n");
log_printf( &logger, " Calibration \r\n");
log_printf( &logger, "- - - - - - - - - - - - - -\r\n");
log_printf( &logger, "> Turn OFF the Power unit <\r\n");
log_printf( &logger, "- - - - - - - - - - - - - -\r\n");
log_printf( &logger, " In the following 5 sec. \r\n");
log_printf( &logger, " turn OFF the Power Supply \r\n");
Delay_ms( 5000 );
log_printf( &logger, "-------------------------\r\n");
log_printf( &logger, " Start calibration \r\n");
if ( adc11_set_calibration( &adc11, &avg_adc_data ) == ADC11_OK ) {
log_printf( &logger, "---------------------------\r\n");
log_printf( &logger, " Calibration Done \r\n");
Delay_ms( 1000 );
}
log_printf( &logger, "---------------------------\r\n");
log_printf( &logger, " Start measurements : \r\n");
log_printf( &logger, "---------------------------\r\n");
}
void application_task ( void ) {
adc11_get_voltage( &adc11, &avg_adc_data, &voltage );
log_printf( &logger, " Volatge : %.3f V \r\n", voltage );
log_printf( &logger, "---------------------------\r\n");
Delay_ms( 2000 );
}
void main ( void ) {
application_init( );
for ( ; ; ) {
application_task( );
}
}
// ------------------------------------------------------------------------ END
