Optimize processes and workflows with accurate distance measurements provided by VL53L0X and PIC18LF46K42
Measure distances with high precision and reliability
Published Nov 01, 2023
Click board™
LightRanger 2 Click
Dev Board
EasyPIC v7
Compiler
NECTO Studio
MCU
PIC18LF46K42
Drive innovation in various fields by integrating gesture recognition and ranging capabilities
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Hardware Overview
How does it work?
LightRanger 2 Click is based on the VL53L0X, the world’s smallest Time-of-Flight (ToF) ranging and gesture detection sensor from STMicroelectronics. The VL53L0X integrates a leading-edge SPAD array (Single Photon Avalanche Diodes) and embeds ST’s second generation FlightSense™ patented technology. FlightSense™ technology measures the time it takes for a photon to reach the nearest object. The photon travel time is multiplied by the speed of light, and a distance is calculated from there. The photon travel time is not affected by reflectance, and this kind of technology is immune to ambient illumination and optical path variations. The VL53L0X’s 940nm VCSEL emitter (Vertical Cavity Surface-Emitting Laser) is invisible to the human eye, and coupled with internal physical infrared filters, it enables longer ranging distance, higher immunity to ambient light
and better robustness to cover-glass optical cross-talk. The VL53L0X has three ranging modes. The Single-ranging mode is performed only once after the function is called. The Continuous ranging mode is performed continuously, and as soon as the measurement is finished, another one is started without delay. The time-ranging mode is the same as the Continuous mode, with a user-defined delay between measurements. LightRanger 2 Click uses a standard 2-Wire I2C serial interface to communicate with the host MCU, supporting speeds up to 400kbit/s. The data can be obtained by polling the sensor over the I2C interface or by an interrupt feature when the sensor sends the interrupt over the INT pin to the host when a new measurement is available. There is an EN pin to turn the sensor ON or OFF. As this Click board™ can work on both the 3.3V and the
5V logic level devices, it features a few logic level translators. For I2C interface logic level translation, the LightRanger 2 Click uses the PCA9306, a dual bidirectional I2C bus and SMBus voltage-level translator from Texas Instruments. For additional enable and interrupt pins, this Click board™ uses a couple of SN74LVC1T45s, single-bit dual-supply bus transceivers with configurable voltage translation, and 3-state outputs from Texas Instruments. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the LOGIC 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
EasyPIC v7 is the seventh generation of PIC development boards specially designed to develop embedded applications rapidly. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB-B. 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 v7 allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of
the EasyPIC v7 development board contains the components necessary for the most efficient operation of the same board. An integrated mikroProg, a fast USB 2.0 programmer with mikroICD hardware In-Circuit Debugger, offers many valuable programming/debugging options and seamless integration with the Mikroe software environment. Besides it also includes a clean and regulated power supply block 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-B (USB-B) 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 v7 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
Architecture
PIC
MCU Memory (KB)
64
Silicon Vendor
Microchip
Pin count
40
RAM (Bytes)
4096
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 EasyPIC v7 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 LightRanger 2 Click driver.
Key functions:
lightranger2_write_byte- This function writes a byte of data to the targeted 8-bit registerlightranger2_read_bytes- This function reads a sequential data starting from the targeted 8-bit registerlightranger2_get_range_continuous- This function gets a range measurement in millimeters when continuous mode is active
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
* \brief LightRanger2 Click example
*
* # Description
* This example collects data from the sensor, calculates it, and then logs the
* results.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization driver,
* enable Vl6180X sensor, hardware reset and sets default configuration of
* Vl6180X, also write log.
*
* ## Application Task
* This is a example which demonstrates the use of LightRanger 2 Click board.
* Measures the distance of the object from the sensor.
* Results are being sent to the Usart Terminal where you can track their changes.
* All data logs on usb uart for aproximetly every 1 sec when the data value changes.
*
*
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "lightranger2.h"
// ------------------------------------------------------------------ VARIABLES
static lightranger2_t lightranger2;
static log_t logger;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
lightranger2_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.
lightranger2_cfg_setup( &cfg );
LIGHTRANGER2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
lightranger2_init( &lightranger2, &cfg );
lightranger2_default_cfg( &lightranger2 );
lightranger2_start_continuous( &lightranger2, 0 );
Delay_ms( 100 );
}
void application_task ( void )
{
uint16_t distance;
distance = lightranger2_get_range_continuous( &lightranger2 );
Delay_ms( 10 );
if ( distance )
{
log_printf( &logger, "Distance: %u mm \r\n", distance );
Delay_ms( 100 );
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
