Qi Receiver Click

NOTE: Qi Receiver Click needs to be placed near the suitable Qi Transmitter, also known as the charging pad, to harvest the transmitted power successfully. Also, lead time and pricing for this product can vary due to the current component shortage in the electronic market.

How does it work?

Qi Receiver Click, as its foundation, uses the P9025AC, a compact Qi-compliant wireless power receiver ideal for a myriad of portable applications looking to take advantage of wireless charging technology from Renesas. This Click board™ utilizes the principles of inductive coupling for wireless power transfer. It uses P9025AC’s integrated synchronous full-bridge rectifier and LDO output stage to convert the harvested wireless power signal from the Wurth Electronik’s 760308103205 wireless power coil into a regulated 5.3V/1A output (unpopulated OUT header) suitable to charge a battery or power a system directly. Its operation automatically initiates WPC AC modulation communication protocols with optimal efficiency. In addition, it employs advanced Foreign Object Detection (FOD) techniques to safeguard the system.

This Click board™ relies on the wireless power transfer standard, developed by the Wireless Power Consortium (WPC), to provide and monitor current and voltage. This standard involves digital communication to transmit the information back to the charging pad. Depending on the received information packets, the charging pad regulates the variable magnetic field's strength, generating more or less power on the receiver coil. The P9025AC includes control circuitry to transmit WPC-compliant message packets to the base station.

When Qi Receiver Click is placed on a WPS Qi-compliant charging pad, it responds to the transmitter's "ping" signal by rectifying the AC power from the transmitter. During the "ping" phase, the rectifier provides about 5V, and an internal linear voltage regulator provides the supply voltage for the digital section of the P9025AC, enabling the Qi protocol communication so that the receiver can synchronize with the charging pad. After the initial synchronization, the system enters the Power Transfer state, and the actual power transfer process is started, monitored via the ST pin routed to the CS pin of the mikroBUS™ socket and indicated by the red Status LED indicator. Termination of the charging process is indicated by the END pin routed to the PWM pin of the mikroBUS™ socket.

To simplify the Power-up and usage of the Qi Receiver Click board™; place the Qi Receiver Click with the inductive coil facing down toward the transmitter, and verify that the STAT LED is illuminated, which means that the power is being transferred. After that, connect the load to the output pads.

One special feature of this device is the possibility to detect foreign metal objects in the charging field, which can be heated up by the eddy currents generated inside, with heat translated into a power loss. This state can be especially problematic if the object is a part of the power harvesting device. To overcome this problem, the P9025AC employs advanced Foreign Object Detection (FOD) techniques to safeguard the system, accurately measure its received power, and compensate for its known losses.

Qi Receiver Click communicates with MCU using the standard I2C 2-Wire interface. The P9025AC can be enabled/disabled through the EN pin routed to the RST pin of the mikroBUS™ socket; hence, offering a switch operation to turn ON/OFF power delivery to the chip. Overvoltage, overcurrent, and thermal shutdown features are also supported. Suppose any of these conditions occurs on the output terminal. In that case, the LDO gets shut down, the charging pad stops transmitting the power, and the host MCU is notified of this situation via an interrupt signal.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via SMD jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to 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.

Specifications

Pinout diagram

This table shows how the pinout on Qi Receiver Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Overtemperature	TEOP	1	AN	PWM	16	END	Charge Termination
Enable	EN	2	RST	INT	15	INT	Interrupt
Charge Select	ST	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	SCL	I2C Clock
	NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Qi Receiver Click electrical specifications

Software Support

We provide a library for the Qi Receiver Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for Qi Receiver Click driver.

Key functions

• Function is used to measure current voltage in volt.

• Function is used to measure current amperage in mA.

• Function is used to measure current frequency in hertz.

• Function is used to enable the device.

Example Description

This application reads voltage, current and frequency.

 void application_task ( void ) 
 { 
     float voltage; 
     float current; 
     float freq; 

     voltage = qireceiver_read_voltage( &qireceiver ); 
     log_printf( &logger, "Voltage : %.2f Vrn", voltage ); 

     current = qireceiver_read_current( &qireceiver ); 
     log_printf( &logger, "Current : %.2f mArn", current ); 

     freq = qireceiver_read_freq( &qireceiver ); 
     log_printf( &logger, "Frequency : %.2f Hzrn", freq ); 

     log_printf( &logger, "-----------------rn" ); 
     Delay_ms( 1000 ); 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.QiReceiver

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MikroElektronika compilers.

mikroSDK

This Click board™ is supported with mikroSDK - MikroElektronika Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.