Getting started with Arduino
This is an “Arduino playground” I built for a friend who was new to electronics. I designed it for hands-on experimentation and included sample projects to spark his creativity.
The 74HC237 chip is a 3-to-8 decoder. It takes a binary value from 0-7 on pins 1-3 and puts 5V on the corresponding output at pins 7,9-15. For example, a binary input of 101 (decimal 5) would put 5V on output #5 (pin 10).
The 74HC4511 chip is a 7-segment decoder. Like the ‘237, it takes a binary value from 0-7 on pins 2,1,7 and lights up the appropriate segments to display that number on a 7-segment display.
To demonstrate the platform, I wrote several sample projects:
- CenterLED: Lights all LEDs by cycling through them very quickly, but lights up one LED brighter than the others.
- LEDPot: The variable resistor controls the PWM LED brightness and also selects one LED in the array.
- LEDSequence: Lights each LED in sequence.
- LEDSequenceSwitch: Lights each LED in sequence, reversing direction when the switch is pressed.
- LEDSequenceSwitchPot: Lights each LED in sequence at a speed controlled by the variable resistor, reversing direction when the switch is pressed. Also debounces the switch input so that one press = one direction change, regardless of how long it is held down.
- Pulse: Pulses the PWM LED on and off.
- SerialVoltage: Given a digit between 0 and 9 on the serial interface, outputs a corresponding voltage between 0 and 5v on the PWM pin.
- SerialVoltageDecimal: Given two digits on the serial interface, interprets them as a decimal voltage (eg '11' = 1.1v) and puts that voltage on the PWM pin.
You can download the sample projects here.
The reference material on the Arduino site is helpful as well: