Intermediate
30 min
0

Experience the accuracy you need for confident weight measurement using ZSC31014 and PIC18F26K80

Redefining weight scales

Load Cell 4 Click with EasyPIC v7a

Published Dec 29, 2023

Click board™

Load Cell 4 Click

Development board

EasyPIC v7a

Compiler

NECTO Studio

MCU

PIC18F26K80

Make daily routines smarter by incorporating our precise weight scale solution

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Hardware Overview

How does it work?

Load Cell 4 Click is based on the ZSC31014, a CMOS integrated circuit for highly accurate amplification and analog-to-digital conversion of differential and half-bridge input signals from Renesas. The ZSC31014 has a fully differential chopper-stabilized preamplifier with eight programmable gain settings (1.5, 3, 6, 12, 24, 48, 96, and 192) through a 14-bit ADC. The resolution of the output depends on the input span and the analog gain setting. The system clock of the ZSC31014 can operate at 1MHz (lower power, better noise performance) or 4MHz (faster sample rates). Internal DSP core uses coefficients stored in EEPROM to calibrate/condition the amplified differential input signal precisely. Temperature can be measured from an internal temperature sensor, which can be calibrated to compensate for the temperature effects of the sensor bridge. After the Power-On

Reset function, the ZSC31014 wakes, and if it receives the Start_CM command during the command window, it goes into Command Mode. This Mode is primarily used in the calibration environment, and during Command Mode, the device executes commands sent by the I2C master. The ZSC31014 remains in Command Mode until it receives the Start_NOM command, which starts the Normal Operation Mode. Operation after the Power-On sequence depends on whether the part is programmed in Sleep Mode or Update Mode. In Sleep Mode, the ZSC31014 waits for commands from the master before taking measurements, while in Update Mode, data is taken at a fixed, selectable rate. Load Cell 4 Click communicates with MCU using the standard I2C 2-Wire interface with a clock frequency from 100 to 400 kHz. The INT pin of the mikroBUS™ socket,

used as an interrupt, rises when new output data is ready and falls when the next I2C communication occurs. It is most useful if the part is configured in Sleep Mode to indicate to the system that a new conversion is ready. Besides, this Click board™ also possesses an Enable pin labeled as EN, routed to the CS pin of the mikroBUS™ socket, which serves to turn the ZSC31014's power supply on/off. 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.

Load Cell 4 Click hardware overview image

Features overview

Development board

EasyPIC v7a is the seventh generation of PIC development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has a broad set of unique functions, such as the first-ever embedded debugger/programmer over USB-C. The development board is well organized and designed so that the end-user has all the necessary elements in one place, such as switches, buttons, indicators, connectors, and others. With four different connectors for each port, EasyPIC v7a allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of the EasyPIC v7a 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 various external power sources, including an external 12V power supply, 7-23V AC or 9-32V DC via DC connector/screw terminals, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART and RS-232 are also included, alongside the well-

established mikroBUS™ standard, three display options (7-segment, graphical, and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from PIC10F, PIC12F, PIC16F, PIC16Enh, PIC18F, PIC18FJ, and PIC18FK families. EasyPIC v7a 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.

EasyPIC v7a double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

64

Silicon Vendor

Microchip

Pin count

28

RAM (Bytes)

3648

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
Enable
RA5
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
RB1
INT
NC
NC
TX
NC
NC
RX
I2C Clock
RC3
SCL
I2C Data
RC4
SDA
Power Supply
5V
5V
Ground
GND
GND
2

Take a closer look

Schematic

Load Cell 4 Click Schematic schematic

Step by step

Project assembly

EasyPIC v7a front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v7a as your development board.

EasyPIC v7a front image hardware assembly
LTE IoT 5 Click front image hardware assembly
MCU DIP 28 hardware assembly
LTE IoT 5 Click complete accessories setup image hardware assembly
EasyPIC v7a Access MB 2 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto DIP image step 7 hardware assembly
EasyPIC PRO v7a Display Selection Necto Step hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

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.

UART Application Output Step 1

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.

UART Application Output Step 2

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".

UART Application Output Step 3

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.

UART Application Output Step 4

Software Support

Library Description

This library contains API for Load Cell 4 Click driver.

Key functions:

  • loadcell4_power_dev - Enable power function

  • loadcell4_tare - Tare the scales function

  • loadcell4_get_weight - Get weight 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 LoadCell4 Click example
 *
 * # Description
 * This is an example that demonstrates the use of the Load Cell 4 click board.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes I2C driver and performs the power on. 
 * Sets tare the scale, calibrate scale and start measurements.
 *
 * ## Application Task
 * The Load Cell 4 click board can be used to measure weight,
 * shows the measurement of scales in grams [ g ].
 * Results are being sent to the Usart Terminal where you can track their changes.
 * All data logs write on USB uart changes for every 4 sec.
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "loadcell4.h"

static loadcell4_t loadcell4;
static log_t logger;

static loadcell4_data_t cell_data;
static float weight_val;

void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    loadcell4_cfg_t loadcell4_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.
    loadcell4_cfg_setup( &loadcell4_cfg );
    LOADCELL4_MAP_MIKROBUS( loadcell4_cfg, MIKROBUS_1 );
    err_t init_flag = loadcell4_init( &loadcell4, &loadcell4_cfg );
    if ( I2C_MASTER_ERROR == init_flag ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }
    loadcell4_default_cfg ( &loadcell4 );
    
    loadcell4_power_dev( &loadcell4, LOADCELL4_PWR_ON );
    Delay_ms( 500 );
    
    log_printf( &logger, "-------------------------\r\n" );
    log_printf( &logger, "     ~~~  STEP 1  ~~~    \r\n" );
    log_printf( &logger, "-------------------------\r\n" );
    log_printf( &logger, "     Tare the scale :    \r\n" );
    log_printf( &logger, "- - - - - - - - - - - - -\r\n" );
    log_printf( &logger, " >> Remove all object << \r\n" );
    log_printf( &logger, "- - - - - - - - - - - - -\r\n" );
    log_printf( &logger, " In the following 10 sec \r\n" );
    log_printf( &logger, " please remove all object\r\n" );
    log_printf( &logger, "     from the scale.     \r\n" );
    Delay_ms( 10000 );
    
    log_printf( &logger, "-------------------------\r\n" );
    log_printf( &logger, "    Start tare scales    \r\n" );
    loadcell4_tare( &loadcell4, &cell_data );
    Delay_ms( 500 );

    log_printf( &logger, "-------------------------\r\n" );
    log_printf( &logger, "   Tarring is complete   \r\n" );
    
    log_printf( &logger, "-------------------------\r\n" );
    log_printf( &logger, "     ~~~  STEP 2  ~~~    \r\n" );
    log_printf( &logger, "-------------------------\r\n" );
    log_printf( &logger, "    Calibrate Scale :    \r\n" );
    log_printf( &logger, "- - - - - - - - - - - - -\r\n" );
    log_printf( &logger, "   >>> Load etalon <<<   \r\n" );
    log_printf( &logger, "- - - - - - - - - - - - -\r\n" );
    log_printf( &logger, " In the following 10 sec \r\n" );
    log_printf( &logger, "place 100 g weight etalon\r\n" );
    log_printf( &logger, "    on the scale for     \r\n" );
    log_printf( &logger, "   calibration purpose.  \r\n" );
    Delay_ms( 10000 );

    log_printf( &logger, "-------------------------\r\n" );
    log_printf( &logger, "    Start calibration    \r\n" );

    if ( loadcell4_calibration( &loadcell4, LOADCELL4_WEIGHT_100G, &cell_data ) == LOADCELL4_OK ) {
        log_printf( &logger, "-------------------------\r\n" );
        log_printf( &logger, "    Calibration  Done    \r\n" );
        log_printf( &logger, "- - - - - - - - - - - - -\r\n" );
        log_printf( &logger, "  >>> Remove etalon <<<  \r\n" );
        log_printf( &logger, "- - - - - - - - - - - - -\r\n" );
        log_printf( &logger, " In the following 10 sec \r\n" );
        log_printf( &logger, "   remove 100 g weight   \r\n" );
        log_printf( &logger, "   etalon on the scale.  \r\n" );
        Delay_ms( 10000 );
    } else {
        log_printf( &logger, "-------------------------\r\n" );
        log_printf( &logger, "   Calibration  Error   \r\n" );
        for ( ; ; );
    }

    log_printf( &logger, "-------------------------\r\n" );
    log_printf( &logger, "   Start measurements :  \r\n" );
    log_printf( &logger, "-------------------------\r\n" );
}

void application_task ( void ) {
    weight_val = loadcell4_get_weight( &loadcell4, &cell_data );
    log_printf( &logger, "     Weight : %.2f g \r\n", weight_val );
    Delay_ms( 100 );
}

void main ( void ) {
    application_init( );

    for ( ; ; ) {
        application_task( );
    }
}

// ------------------------------------------------------------------------ END

Additional Support

Resources