Analog & Serial

More interesting interactions with the world.

Outline

• Quantization
• Pulse-Width Modulation (PWM)
• Potentiometers
• Analog to Digital Conversion (ADC)
• map() function
• Hysteresis
• Serial communication:
  • RX vs TX
  • Baud rate
  • Parity
  • Serialization
  • Serial console
• ASCII encoding
• RGB(A) color model
• RGB LEDs
• Serial debugging

Exercises

1. In anticipation of building your own audio amplifier, you decide to create a volume indicator. Using four LEDs, create a 4-LED volume indicator where a potentiometer serves as the volume knob. Ensure that hysteresis is added to each of the volume regions to prevent flickering of volume levels.

2. Since I’m a huge Pink Floyd fan, let’s pick Any Colour You Like. Utilize three potentiometers to change the color of an RGB LED to any color you like. Optionally, add a button to dim the LED brightness by 50%.

3. Since moving our hands from the keyboard is such a hassle, let’s instead utilize the serial console to control the color of the LED. Your code should expect a valid hex RGB value followed by a newline. If this value is malformed, return an error to the user with a meaningful error code; otherwise, return a success code. Optionally, add support for an optional alpha channel. If the user supplies no alpha channel, assume alpha is 100%.