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Week 9: Input Devices

Week 9 assignment is to probe an input device’s analog levels and digital signals. Revisankar had made a board using INMP441 MEMS microphone. We used that board to probe the microphone. Also we tested PS2 Joystick Module Breakout Sensor.

INMP441Board

INMP441

Image taken from Amazon PS2Joystick

Image taken from Arduino Get Started

Setup and Equipment Used

  • INMP441 MEMS microphone
  • PS2 Joystick Module Breakout Sensor
  • Power Supply
  • OWON TA03104A 14-bit High Resolution Tablet Oscilloscope

Testing the INMP441

  1. For INMP441 we used USB and programmer to power the board.
  2. We then connected the hook of the Oscilloscope probe to SD pin (which will provide the signal) and the GND lead to GND of the module respectively.

Testing the PS2 Joystick

  1. For PS2 Joystick we used the Bench Power Supply to provide the power. We used female-to-male jumper wires to connect the PWR lead to 5V and GND lead to GND pins of the module respectively.
  2. We then connected the hook of the oscilloscope probe to VRX (which will provide the signal) and the GND lead to GND of module

Bench Top Power Supply

Power Supply Connection: The bench power supply was connected to provide a stable 5V power source to the Joystick sensor. PowerSupply

Oscilloscope Setup

We used the OWON TA03104A to measure voltage. Oscilloscope

  1. Calibrated the probes using the square wave and autoset button.
  2. Selected CH1
  3. Adjusted the voltage, time period, and zoomed into waveform after pressing HOR button.
  4. Provided previously mentioned connections
  5. Pressed run/stop to get a still view of the wave for analysis.

Output

This is the highest resolution of the waveform we could achieve for the digital signal of INMP441 MEMS microphone.

Conclusion

Through our experimentation, we have sucessfully visualized the digital signal output of the INMP441 and the analog signal output of the PS2 Joystick Module.

Last update: March 26, 2025