Bridge the gap between the analog and digital domains with ADS1262 and PIC18F85K22
From waves to digits
Published Jun 01, 2023
Click board™
ADC 13 Click
Dev Board
Fusion for PIC v8
Compiler
NECTO Studio
MCU
PIC18F85K22
Achieve greater data accuracy and precision than ever before with our high-performance ADC
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Hardware Overview
How does it work?
ADC 13 Click is based on the ADS1262, a low noise, low-drift, 38.4kSPS, delta-sigma (ΔΣ) ADC with an integrated PGA, reference, and internal fault monitors from Texas Instruments. This 32-bit ADC provides output data rates from 2.5 to 38400SPS for flexibility in resolution and data rates over various applications. The ADC's low noise and low drift architecture make these devices suitable for precisely digitizing low-level transducers, such as load cell bridges and temperature sensors. Following the input multiplexer, ADS1262 features a high-impedance CMOS, a programmable gain amplifier, which provides a low voltage and current noise, enabling direct connection to low-level transducers. The PGA gain is programmable from 1 to 32V/V in binary steps, can be bypassed to allow the input range to extend below ground, and has voltage
over-range monitors to improve the integrity of the conversion result. The ADS1262 communicates with MCU using the standard SPI serial interface with a maximum frequency of 8MHz to read the conversion data and configure and control the ADC. ADC conversions, which can be programmed to a free-run mode or perform one-shot conversions, are started by a control STR pin, routed to the PWM pin of the mikroBUS™ socket, or by commands. An additional ready signal, routed on the INT pin of the mikroBUS™ socket labeled as DTR, is added, indicating that new data is ready for the host. Alongside this pin, this Click board™ has a Reset feature routed to the RST pin on the mikroBUS™ socket, which with a low logic level, puts the module into a Reset state, and with a high level, operates the module normally.
In addition to the ADS1262 present on the ADC 13, this Click board™ has two 2x3 male headers. Eleven analog inputs on these headers are configurable as either ten single-ended inputs, five differential inputs, or any combination. Many of the analog inputs are multifunction as programmed by the user. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. 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
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)
32
Silicon Vendor
Microchip
Pin count
80
RAM (Bytes)
2048
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 13 Click driver.
Key functions:
adc13_cfg_setup- Config Object Initialization function.adc13_init- Initialization function.adc13_default_cfg- Click Default Configuration 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 ADC13 Click example
*
* # Description
* This example demonstrates the use of ADC 13 click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs the click default configuration.
*
* ## Application Task
* Reads the voltage between AIN0 and AIN1 channels, and the module internal temperature as well.
* All values are being displayed on the USB UART where you can track their changes.
*
* @note
* An internal 2.5V reference is set by default.
* If you want, you can change it using the adc13_set_voltage_reference function.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "adc13.h"
static adc13_t adc13;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
adc13_cfg_t adc13_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.
adc13_cfg_setup( &adc13_cfg );
ADC13_MAP_MIKROBUS( adc13_cfg, MIKROBUS_1 );
err_t init_flag = adc13_init( &adc13, &adc13_cfg );
if ( SPI_MASTER_ERROR == init_flag )
{
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
adc13_default_cfg ( &adc13 );
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float voltage = 0;
float temperature = 0;
adc13_measure_voltage ( &adc13, ADC13_VREF_INTERNAL, &voltage );
log_printf( &logger, " Voltage: %.3f V\r\n", voltage );
adc13_measure_temperature ( &adc13, &temperature );
log_printf( &logger, " Temperature: %.2f C\r\n", temperature );
log_printf( &logger, " ---------------------------\r\n" );
Delay_ms( 500 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
