Fine-tune resistance or any other parameter in a circuit with PTA3043-2015CPB103 and PIC32MZ2048EFM100

Precision in your hands: Redefine control with our mechanical slider

Published Oct 10, 2023

Click board™

Slider Click

Dev. board

Curiosity PIC32 MZ EF

Compiler

NECTO Studio

MCU

PIC32MZ2048EFM100

Our mechanical slide potentiometer, equipped with built-in LEDs to visualize its position, is designed to revolutionize control and provide a smooth and accurate way to adjust various parameters while offering real-time visual feedback

Hardware Overview

How does it work?

Slider Click is based on two sections: the first section is the slider section itself, with the sliding potentiometer end terminals connected between GND and the VCC, and the wiper connected to the MCP3551 IC, which is a low-power, single-channel 22-bit delta-sigma ADC from Microchip. The slider acts as a voltage divider so that the voltage between the GND and the wiper position is determined by the slider position. This voltage is then applied to the input pin of the 22bit ADC converter and converted to a digital value. The MCP3551 has its SPI lines routed to the mikroBUS™ so that the values can be read easily

by the MCU. The second section of this Click board™ consists of the MAX6969, a well know 16-port, constant-current LED driver from Maxim Integrated, used to control the SMD LEDs. The MAX6969 IC uses the same SPI lines as the ADC, but to avoid data collision, different chip select (CS) line is used. While the ADC uses the CS line routed to the CS pin of the mikroBUS™, the LED driver uses the RST line of the mikroBUS™ as the chip select input. This allows to work with both ICs independently. MAX6969 output enable (OE) pin is routed to the AN pin of the mikroBUS™, making it easy to completely turn off the output stage

of the MAX6969, by setting this pin to a HIGH logic state. If left floating, this pin will be pulled down to the GND by the 10K resistor. The output LED current is constant and it is set to around 20mA by the resistor on the SET pin of the MAX6969. 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. 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

Curiosity PIC32 MZ EF development board is a fully integrated 32-bit development platform featuring the high-performance PIC32MZ EF Series (PIC32MZ2048EFM) that has a 2MB Flash, 512KB RAM, integrated FPU, Crypto accelerator, and excellent connectivity options. It includes an integrated programmer and debugger, requiring no additional hardware. Users can expand

functionality through MIKROE mikroBUS™ Click™ adapter boards, add Ethernet connectivity with the Microchip PHY daughter board, add WiFi connectivity capability using the Microchip expansions boards, and add audio input and output capability with Microchip audio daughter boards. These boards are fully integrated into PIC32’s powerful software framework, MPLAB Harmony,

which provides a flexible and modular interface to application development a rich set of inter-operable software stacks (TCP-IP, USB), and easy-to-use features. The Curiosity PIC32 MZ EF development board offers expansion capabilities making it an excellent choice for a rapid prototyping board in Connectivity, IOT, and general-purpose applications.

Microcontroller Overview

MCU Card / MCU

Architecture

PIC32

MCU Memory (KB)

2048

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

LED Driver Output Enable

RPB4

LED Driver SPI Chip Select

RA9

RST

ADC SPI Chip Select

RPD4

SPI Clock

RPD1

SCK

SPI Data OUT

RPD14

MISO

SPI Data IN

RPD3

MOSI

Power Supply

3.3V

Ground

GND

PWM

INT

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

Curiosity PIC32MZ EF front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity PIC32 MZ EF as your development board.

GNSS2 Click front image hardware assembly

Board mapper by product7 hardware assembly

Curiosity PIC32 MZ EF MCU Step hardware assembly

Necto No Display image step 8 hardware assembly

Debug Image Necto Step hardware assembly

Software Support

Library Description

This library contains API for Slider Click driver.

Key functions:

slider_read_adc_and_ready - Function calls slider_readADC function, but first checks is ADC conversion finished
slider_enable_led_output - Function enables LED output to shows output laches when state is low, and disables LED output when state is high
slider_enable_output_laches - Function enables output laches to monitor converted ADC value, when state is high

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 Slider Click example
 * 
 * # Description
 * This example detect even the smallest move, faithfully capturing the smoothness of 
 * the slider movement, while digitizing its position.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes Click driver
 * 
 * ## Application Task  
 * Converts analog input voltage (VCC), witch value depends on the slider position,
 * to digital output value, shows result of conversion on LED and logs result on USB UART.
 * 
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "slider.h"

// ------------------------------------------------------------------ VARIABLES

static slider_t slider;
static log_t logger;

static float adc_value;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    slider_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.

    slider_cfg_setup( &cfg );
    SLIDER_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    slider_init( &slider, &cfg );
    Delay_ms ( 200 );

}

void application_task ( void )
{
    adc_value = slider_write_output( &slider );
    log_printf( &logger, "%.2f\r\n", adc_value );
    Delay_ms ( 100 );
}

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