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Week12 - Input Device

Here are my week 12 assignment​

I want to design a module that supports audio input. The final one will support output and intereact with my reComputer. Here I will design a simple one for the beginning.

What should I achieve in this week:​

Group Assignment:​

  • Probe an input device's analog levels and digital signals

individual assignment:​

  • Measure something: add a sensor to a microcontroller board that you have designed and read it

Notes about Input Device​

Get singal into the microcontrollers, the input devices.

The communication/protocols: ports, comparator, A/D, I2C

I2C: SCL and SDA, two pull up registors

switch: button, switch - for more detailed, once you push the button, there will be some bounces.

magnet: hall effect sensor, current will change from the magnetic field, there are a 3D type - output/sensing the x,y,z about under the magnetic field - joy sticks, gaming system

potentiometer: variable resistor

step response: touch pad - sensing the postion of the pad, LVTD

  • series connection with 1M resistor and line, there are magentic field between plates.
  • measuring the chaning curve of the time/voltage, fix the time and measure the voltage, or fix the voltage and measure the time
  • XIAO RP2040 includes PIO which is a main processor and 8 federated processors
  • ensure the design that can protect the inner components
  • loop setting, settling time, avliding noise hint: using comparator to measure the current/voltage for there might be some distance in the PCB

temperture: the resistor is depending on the temperature, once connected, measure the current or voltage

  • The "bridge": measure the small change, connect the "bridge" with a amplifier

light: the resistor is depending on the light, once connected, measure the current or voltage

  • there are different types of light sensor, can measure differnt lights, reflection

motion: the radar, sending the signals to the object and measure the save feedback, to see whether is moving

distance: like radar, transmit the light and then receive finally output

location, time: thanks to the addtional function module, once connected, the signal will send automatically

acceleration: 9-axis IMU(inertial measurement unit) - 3 accelerometer for x, y, z, 3 gyroscope for xyz and 3 magnetometer for magnetic field - absolute oritentation. 6-axis IMU just 3 accelerometer and 3 gyroscope ; 3-axis IMU just 3 accelerometer.

sound: microphone measure audio.

  • I2S(I2C-similar) - specifically for sound, the commonication protocols, which means using SDA SCL, I2S Arduino library.
  • microphone on the bottom, not the top of the package
  • electrect is obsolete

vibration: knock on the door, shake something, tab on the door

force: the push, resistor can change by the pressure

angle: differnt point

pressure: more for air pressure, for the human pressure is force

try to make the ground is not far way from the sensor, for the interface - protection design

pulse: heartbeat sensor

air-pollution: chemical reaction

image: like the camera sensor on XIAO ESP32S3 Sense

  • OpenCV is the most poopluar libraries for camera sensing
  • WebRTC: create a serial port from the brower (Thess.js)