The Grove 2-Channel Inductive Sensor is based on Texas Instruments(TI) LDC1612, a 28-bit inductance to digital converter(LDC) for inductive sensing solutions. With multiple channels and support for remote sensing, the LDC1612 enables the performance and reliability benefits of inductive sensing to be realized at minimal cost and power. Inductance is an effect caused by the magnetic field of a current-carrying conductor acting back on the conductor. So by sensing the inductance, this sensor can detect the proximity of conductors especially metal nearby.
LDC1612 works based on measuring the parameters of the LC oscillator, formed by the PCB copper trace and the capacitor.
LDC1612 is able to measure the amount of energy it needs to provide to maintain the LC oscillation when a conductive object is magnetically coupled with the LC oscillator approach. As the power loss of the oscillator circuit is proportional to the impedance of the conducting object, and the impedance value is affected by the distance of the object, it can then be used to determine the distance between the object and the LC oscillator. In this case, the PCB copper trace can be seen as an impedance sensor.
Highlighted Features
- Excellent sensing range: Remote sensor position of >20 cm and supports wide sensor frequency range of 1 kHz to 10 MHz and 2 channels with the matched sensor drive
- Powerful anti-interference and outstanding durability: Supports operation in harsh environments, Immunity to DC magnetic fields and magnets, and aging compensation
- Multiple references clocking options: Included internal clock for lower system cost and support for 40 MHz external clock for higher system performance.
- Low power consumption: 35 µA low power sleep mode and 200 nA shutdown mode
- Grove unified socket: The sensor ensures "Plug and Play" and could be versatile for various applications.
Applications
- Knobs in consumer, appliances, and automotive
- Linear and rotational encoders
- Buttons in home electronics, wearables, manufacturing, and automotive
- Keypads in manufacturing and appliances
- Slider buttons in consumer products
- Metal detection in industrial and automotive
- POS and EPOS
- Flow meters in consumer and appliances
Hardware Overview
Figure 1: Connection Point
Figure 2: Device Schematics