Measure force or weight of an object with ADS1230 and PIC18F47Q10
Force meter
Published Mar 04, 2023
Click board™
Load Cell 7 Click
Dev Board
Curiosity HPC
Compiler
NECTO Studio
MCU
PIC18F47Q10
Complete front-end for bridge sensing applications
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Hardware Overview
How does it work?
Load Cell 7 Click is based on the ADS1230, a high accuracy, low noise, and low power 20-bit ΣΔ ADC with an outstanding noise performance from Texas Instruments. It includes a low-noise PGA, internal oscillator, third-order delta-sigma (ΔΣ) modulator, and fourth-order digital filter, thus providing a complete front-end solution for bridge sensor applications. The ADS1230 is easy to configure, and all digital control is accomplished through dedicated pins; there are no programmable registers. The conversions from the ADS1230 are sent to the MCU through SPI serial interface, with the digital information converted to weight. The low-noise PGA has a selectable gain,
performed by an onboard SMD jumper labeled as GAIN SEL to an appropriate position marked as 64 and 128, supporting a full-scale differential input of ±39mV or ±19.5mV, respectively. Besides, data can be output at 10SPS for excellent 50Hz and 60Hz rejection or at 80SPS when higher speeds are needed. The onboard SMD jumper labeled SPS SEL can select this feature, placing it in an appropriate position marked as 10 and 80. The ADS1230 can be put in a low-power standby mode or shut off completely in power-down mode. This Click board™ uses the 4-wire load cell configuration, with two sense pins and two output connections. The load cell differential S lines connected to
the AD7780 reference inputs create a ratiometric configuration immune to low-frequency power supply excitation voltage changes. Those sense pins are connected to the high and low sides of the Wheatstone bridge, where voltage can be accurately measured, regardless of the voltage drop due to the wiring resistance. 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
Curiosity HPC, standing for Curiosity High Pin Count (HPC) development board, supports 28- and 40-pin 8-bit PIC MCUs specially designed by Microchip for the needs of rapid development of embedded applications. This board has two unique PDIP sockets, surrounded by dual-row expansion headers, allowing connectivity to all pins on the populated PIC MCUs. It also contains a powerful onboard PICkit™ (PKOB), eliminating the need for an external programming/debugging tool, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, a set of indicator LEDs, push button switches and a variable potentiometer. All
these features allow you to combine the strength of Microchip and Mikroe and create custom electronic solutions more efficiently than ever. Each part of the Curiosity HPC development board contains the components necessary for the most efficient operation of the same board. An integrated onboard PICkit™ (PKOB) allows low-voltage programming and in-circuit debugging for all supported devices. When used with the MPLAB® X Integrated Development Environment (IDE, version 3.0 or higher) or MPLAB® Xpress IDE, in-circuit debugging allows users to run, modify, and troubleshoot their custom software and hardware
quickly without the need for additional debugging tools. Besides, it includes a clean and regulated power supply block for the development board via the USB Micro-B connector, alongside all communication methods that mikroBUS™ itself supports. Curiosity HPC development board allows you to create a new application in just a few steps. Natively supported by Microchip software tools, it covers many aspects of prototyping thanks to many number of different Click boards™ (over a thousand boards), the number of which is growing daily.
Microcontroller Overview
MCU Card / MCU
Architecture
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
40
RAM (Bytes)
3615
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 HPC as your development board.
Track your results in real time
Application Output
This Click board can be interfaced and monitored in two ways:
Application Output- Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.
UART Terminal- Monitor data via the UART Terminal using a USB to UART converter. For detailed instructions, check out this tutorial.
Software Support
Library Description
This library contains API for Load Cell 7 Click driver.
Key functions:
loadcell7_tare_scaleThis function calculates the @b ctx->tare_scale which is the raw ADC readings of the empty container.loadcell7_calibrate_weightThis function calibrates the weight by calculating the @b ctx->weight_scale for the input calibration weight.loadcell7_get_weightThis function calculates the weight of the goods in grams.
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 main.c
* @brief Load Cell 7 Click example
*
* # Description
* This example demonstrates the use of Load Cell 7 click by measuring the weight
* in grams of the goods from the load cell sensor connected to the click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and reads the tare scale of the empty container, and after
* that, it calibrates the weight scale with a known calibration weight.
*
* ## Application Task
* Reads the net weight of the goods in grams approximately once per second and logs the
* results on the USB UART.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "loadcell7.h"
// Enter below the weight in grams of the goods with a known weight which
// you will use to calibrate the scale weight.
#define LOADCELL7_CALIBRATION_WEIGHT_G 1000.0
static loadcell7_t loadcell7;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
loadcell7_cfg_t loadcell7_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.
loadcell7_cfg_setup( &loadcell7_cfg );
LOADCELL7_MAP_MIKROBUS( loadcell7_cfg, MIKROBUS_1 );
if ( SPI_MASTER_ERROR == loadcell7_init( &loadcell7, &loadcell7_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
log_printf( &logger, " Remove all goods from the scale in the following 5 sec.\r\n");
Delay_ms ( 5000 );
log_printf( &logger, " Calculating tare scale...\r\n");
if ( LOADCELL7_OK == loadcell7_tare_scale ( &loadcell7 ) )
{
log_printf( &logger, " Tarring complete!\r\n\n");
}
else
{
log_error( &logger, " Calculating tare scale.");
for ( ; ; );
}
log_printf( &logger, " Place a %ug calibration weight on the scale in the following 5 sec.\r\n",
( uint16_t ) LOADCELL7_CALIBRATION_WEIGHT_G );
Delay_ms ( 5000 );
log_printf( &logger, " Calibrating weight...\r\n");
if ( LOADCELL7_OK == loadcell7_calibrate_weight ( &loadcell7, LOADCELL7_CALIBRATION_WEIGHT_G ) )
{
log_printf( &logger, " Calibration complete!\r\n\n");
}
else
{
log_error( &logger, " Calibrating weight.");
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float weight;
if ( LOADCELL7_OK == loadcell7_get_weight ( &loadcell7, &weight ) )
{
log_printf(&logger, " Weight : %.2f g\r\n", weight );
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
