LDC1000 Click

How does it work?

LDC1000 Click is based on the LDC1000, a low-power inductance-to-digital converter from Texas Instruments. The LDC1000 simultaneously measures an LC resonator’s impedance and resonant frequency by regulating the oscillation amplitude in a closed-loop configuration to a constant level while monitoring the energy dissipated by the resonator. By monitoring the amount of power injected into the resonator, the LDC1000 can determine the impedance value and return it as a digital value. In addition, the LDC1000 can also measure the oscillation frequency of the LC circuit, used to determine the inductance of the LC circuit, also given in a digital format. The LDC1000 has a sub-micron resolution in short-range applications suitable for precise short-range measurements of the position, motion, or composition of conductive targets.

This Click board™ comes with a detachable sensor (an LC tank comprising a 36-turn PCB coil and a 100pF 1% NPO capacitor). The LDC measures the inductance change that a conductive target causes when it moves into the inductor’s AC magnetic field to provide information about the target’s position over a sensor coil. The inductance shift is caused by eddy currents (circulating currents) generated in the target due to the sensor’s magnetic field. These currents make a secondary magnetic field that opposes the sensor field, causing a shift in the observed inductance, used for precise positioning of the target as it moves laterally over the sensor coil.

The LDC1000 communicates with MCU using the standard SPI serial interface with a maximum frequency of 4MHz. It also has an interrupt pin routed to the INT pin of the mikroBUS™ socket, which can be configured in three different ways by programming the interrupt mode register. An interrupt pin can act as a proximity switch with programmable hysteresis, a wake-up feature, or a data-ready pin indicating a valid condition for new data availability. Inductive sensing of this LDC is highly reliable where harsh conditions don’t hinder the performance of LDC1000. Alongside the detachable sensor, the onboard INA and INB pins allow you to replace the provided sensor and solder your own.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the I/O Level 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 LDC1000 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	NC
	NC	2	RST	INT	15	INT	Interrupt
SPI Chip Select	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
SPI Data OUT	SDO	5	MISO	SCL	12	NC
SPI Data IN	SDI	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

LDC1000 Click electrical specifications

Software Support

We provide a library for the LDC 1000 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 LDC 1000 Click driver.

Key functions

• This function reads the proximity data.

• This function reads the inductance data.

• This function reads the input voltage from the INT pin.

Example Description

This example showcases how to initialize and configure the logger and click modules and read and display proximity and impendance data.

 void application_task ( ) 
 { 
     uint16_t proximity; 
     uint16_t inductance; 

     proximity = ldc1000_get_proximity_data( &ldc1000 ); 
     inductance = ldc1000_get_inductance_data( &ldc1000 ); 

     if ( ( ( proximity - old_proximity ) > LDC1000_SENSITIVITY ) && 
          ( ( old_proximity - proximity ) > LDC1000_SENSITIVITY ) ) 
     { 
         log_printf( &logger, " * Proximity: %d rn", proximity ); 

         log_printf( &logger, " * Impendance: %f uHrn", inductance ); 

         old_proximity = proximity; 

         log_printf( &logger, "--------------------rn" ); 
         Delay_100ms(); 
     } 
 }

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.Ldc1000

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.