Beginner
10 min

Simplify the charging process with newest Qi RX solution based on the PIC16F15313 and PIC18F46K20

Wireless power transfer solution

Qi RX Click with EasyPIC v8

Published Nov 01, 2023

Click board™

Qi RX Click

Development board

EasyPIC v8

Compiler

NECTO Studio

MCU

PIC18F46K20

Choose Qi RX for a smarter, wireless power solution that transforms the way you charge, streamlining your energy supply with unprecedented accuracy.

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Hardware Overview

How does it work?

Qi RX Click is based on the PIC16F15313, a general-purpose 8-bit MCU that makes a flexible, low-cost alternative to wireless charging solutions based on ASICs from Microchip. The Qi RX Click allows users to quickly add wireless charging functionality to their projects without dealing with complex specific protocols or state machines. It is implemented using a general-purpose 8-bit MCU compatible with the Qi 1.1 (5W) standard. It can be used with any Qi 1.1 compatible wireless charging transmitter with the added functionality of a fully-featured Li-Ion charging controller. Wireless charging uses the principle of magnetic induction to transfer power, similar to a conventional AC transformer, where the receiver and the transmitter coils represent the transformer windings. The high-frequency signal of the Receiver Coil is rectified by a simple full-bridge rectifier implemented with four Schottky diodes (D1-D4), which output voltage is then monitored by the PIC16F15313 through a simple resistive divider R4 and R5. The communication with the

base transmitter is implemented using Amplitude Shift Keying (ASK), as recommended by the Qi 1.1 standard, with two low-power MOSFETs (Q1 and Q2) and two capacitors (C4 and C5) used to modulate the absorbed power. The rectified voltage is also applied at the input of the MCP1755, a low drop-out voltage regulator from Microchip that supplies the 5V voltage for the battery charger and the PIC16F15313 up to 300mA. This LDO is associated with the charge LED indicator labeled CHG, which will indicate the charging progress and turn off once the battery charging is finished. The battery charging functionality is provided by the MCP73830, a single-cell Li-Ion/Li-Polymer battery charge management controller from Microchip. The input current is measured by the PIC16F15313 using a shunt resistor R2 and the MCP6001, a single general-purpose OpAmp offering rail-to-rail input and output up to 6V from Microchip. The gain of this amplifier is set to 10. Measurement of the input current is necessary to accurately calculate input power and implement

the Foreign Object Detection (FOD) function using the power loss method. Qi RX Click communicates with MCU using the MCP3221, a successive approximation A/D converter with a 12-bit resolution from Microchip. This device provides one single-ended input with very low power consumption, a low maximum conversion current, and a Standby current of 250 μA and 1 μA. Data can be transferred at rates of up to 100 kbit/s in the Standard and 400 kbit/s in the Fast Mode. Also, maximum sample rates of 22.3 kSPS with the MCP3221 are possible in a Continuous-Conversion Mode with a clock rate of 400 kHz. 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.

Qi RX Click hardware overview image

Features overview

Development board

EasyPIC v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports many high pin count 8-bit PIC microcontrollers from Microchip, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer. 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, EasyPIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the EasyPIC 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 DEVICE, and CAN are also included, including the well-established mikroBUS™ standard, two display options (graphical and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from the smallest PIC MCU devices with only eight up to forty pins. EasyPIC 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.

EasyPIC v8 horizontal image

Microcontroller Overview

MCU Card / MCU

PIC18F46K20

Architecture

PIC

MCU Memory (KB)

64

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

3936

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
I2C Clock
RC3
SCL
I2C Data
RC4
SDA
Power Supply
5V
5V
Ground
GND
GND
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Take a closer look

Schematic

Qi RX Click Schematic schematic

Step by step

Project assembly

EasyPIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v8 as your development board.

EasyPIC v8 front image hardware assembly
Buck 22 Click front image hardware assembly
MCU DIP 40 hardware assembly
EasyPIC v8 DIP MB 1 - 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
Necto image step 8 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 Qi RX Click driver.

Key functions:

  • qirx_read_data - Read data function.

  • qirx_read_voltage - Read voltage 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 QiRX Click example
 *
 * # Description
 * This is an example that demonstrates the use of the Qi RX Click board.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initalizes I2C driver and makes an initial log.
 *
 * ## Application Task
 * This example shows the capabilities of the Qi RX click by measuring voltage of the connected
 * battery. In order to get correct calculations user should change "v_ref" value 
 * to his own power supply voltage.
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "qirx.h"

static qirx_t qirx;
static log_t logger;
uint16_t voltage;
uint16_t v_ref = 5058;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    qirx_cfg_t qirx_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.
    qirx_cfg_setup( &qirx_cfg );
    QIRX_MAP_MIKROBUS( qirx_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == qirx_init( &qirx, &qirx_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    log_printf( &logger, "----------------------- \r\n" );
    log_printf( &logger, "      Qi RX click       \r\n" );
    log_printf( &logger, "----------------------- \r\n" );
    
    log_info( &logger, " Application Task " );
    log_printf( &logger, "----------------------- \r\n" );
}

void application_task ( void ) 
{
    voltage = qirx_read_voltage( &qirx, v_ref );
    log_printf( &logger, " Battery voltage: %d mV \r\n", voltage );
    log_printf( &logger, "----------------------- \r\n" );
    Delay_ms( 2000 );
}

void main ( void ) 
{
    application_init( );

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

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

Additional Support

Resources