Hello readers welcome to new post here we will discuss Introduction to MPR121 Capacitive Touch Sensor. The MPR121 is created after the MPR03x series devices’ common applications. The MPR121 comes with enhanced inner intelligence with Freescale 2nd generation capacitance detection engine. With other features it has are electrode count, and hardware configuration 12c protocol.In this post, we will cover its details about the different paramerts such as working, pinouts, and applications so let get started.
Introduction to MPR121 Capacitive Touch Sensor
- MPR121 is a capacitive touch sensing device that operates through I2c interfacing. This board can be regulated till the 12 single electrodes with 13 simulated electrodes,
- There are 8 light-emitting diode pins it has when these pins are not used as electrodes work to operate any LED.
- It comes with 4 jumpers wires that adjust with the default setting.
- Jumper connects with the Add pinout with the ground it indicates that the default address of the board will be 0x5A
- Before varying the address of the board there must open jumper. Jumper also has SDA, SCL and interrupt pinout with the ten kilo pull-up resistances.
- There is no existence of regulation at the board hence voltage is given must be between 2.5 to 3.6 volts dc.
- The connection of VREG pin to ground with the series combination of 0.1 microFarad capacitor that indicates till you will not adjust the board MPR121 can not run for supply volts of 1.71 to 2.75 volts dc
MPR121 Pinout
- The main pinout of MPR121 are discussed here
- 0 to 11: These pins are used as inputs for capacitive sensors.
- GND: It is ground pins
- ADD: it used as an address selector of I2c
- SDA: It used for serial transmission of data through i2c
- SCL: Serial clock is given here
- IRQ: It is an open-drain interrupt output pinout
- 3.3V: Input power is given here
MPR121 Features
- Its main features are discussed here.
- The voltage range for this board is 1.71 to 3.6 volts.
- Twenty-nine microamperes input current can it get
- Its shutdown current is three microamperes.
- It comes with twelve electrodes on the board.
- It has an LED operating circuit with eight LED pins.
- Its operating temperature is minus forty to plus eighty-five centigrade.
MPR121 Applications
- The main applications of MPR121 are discussed here.
- It is used in computer systems.
- Used in sound systems
- It is used in circuits of remote controllers of different devices.
- It is used in mobile
- Employed for control of light through sensors without a switch
Working of Capacitive Touch Sensor Module
- The capacitor is an electronic component that stores charge for a short time. It is good for features of making voltage increases in a linear way if constant current is given and exponentially if connected with a resistor to a constant voltage source.
- These features are employed for timing circuits. If one end of the capacitor is connected with the circuit and the other is made with a floating body, the result is that the time constant of the circuit varies.
- It is the main working feature of the capacitive touch sensor; one end is connected with an IC that employs a time constant for generating a signal, and the other is made with finger-touching contact. This circuit is completed with parasitic capacitance with ground.
- MPR121 is an IC that needed to apply 12 capacitive touch sensors. The 12 pins can be configured with electrodes that are metallic pads.
- 8th pin is double since LED driver output The I2C protocol is used for communication with ICs. 4 different addresses are used through making a connection with ADD pin with ground, VCC, SCL, or SDA.
FAQs
What does a capacitive touch sensor do?
- There are different types of sensors used for capacitive seeing, such as sensors for detection and measuring proximity, position and displacement, force, fluid level, and acceleration. Human interface devices configured on capacitive sensing, like touchpads, replaced computer mice.
What is the sampling rate of MPR121?
- MPR121 is configured with a sampling interval between 1 1ms and 128 128ms.
What is the voltage of MPR121?
- MPR121 operated in a voltage range of 2 to 3.6 volts. The VDD pin is the main supply input for MPR121 and decoupled with a 0.1uF ceramic capacitor with Vss. High noise for VDD is avoided. The VDD pin comes with a working voltage range of 1.71V to 3.6V.
Read also
That is all about the MPR121 Capacitive Touch Sensor. I have explained all the parameters about these modules with the details if you have any further queries ask on the comments thanks for reading have a good day.
