Hello, I do not think your project is silly. It is doable. For example, wireless communication work very poorly under water. So this could be a simple metod for two wire, robust, communication. The cable work as a capacitor. So, for long lenghts, you would see the voltage charge the "capacitor", voltage rise pulse ramp up/down issues. We do not know what cable you have. But this can be tested. For long distances, some company "coil up" the cable, to avoid this capacitor effekt, as the coil work as a inductor, "reversing" the capacitor effect. You could also use resistors to change the ramp up/down pulse voltage rise/decay.
The code is not that hard to understand: Simple analog read and IF statements. So you need to send different voltages to the cable reciver. This is done with resistor devider circuits usings ohms law.
Your suggestion reminds me about the arduino lcd display shield with pushbuttons. It use resistor devider circuit you talk about. Maybe you could even use it for your project. Note, the code is for example only. Here is the code and pay attetion the the if statements in the bottom:
/* YourDuino.com Example Software Sketch
TEST LCD Display with Pushbuttons
Based on code by Mark Bramwell and debouncing by peterstrobl
terry@yourduino.com */
/*-----( Import needed libraries )-----*/
#include <LiquidCrystal.h>
/*-----( Declare objects )-----*/
LiquidCrystal lcd(8, 9, 4, 5, 6, 7); //These are the pins used on this shield
/*-----( Declare Constants )-----*/
#define btnRIGHT 0
#define btnUP 1
#define btnDOWN 2
#define btnLEFT 3
#define btnSELECT 4
#define btnNONE 5
/*-----( Declare Variables )-----*/
int lcd_key = 0;
int adc_key_in = 0;
int adc_key_prev = 0;
void setup() /*----( SETUP: RUNS ONCE )----*/
{
lcd.begin(16, 2); // start the lcd object
lcd.setCursor(0,0);
lcd.print("Push A Button!");
lcd.setCursor(10,1);
lcd.print("A="); // For display of A0 Analog values from button push
}/*--(end setup )---*/
void loop() /*----( LOOP: RUNS CONSTANTLY )----*/
{
lcd.setCursor(7,1); // move cursor to second line "1" and 7 spaces over
lcd.print(millis()/1000); // display seconds elapsed since power-up
adc_key_prev = lcd_key ; // Looking for changes
lcd_key = read_LCD_buttons(); // read the buttons
if (adc_key_prev != lcd_key)
{
lcd.setCursor(12,1);
lcd.print(" "); // Blank, display returned Analog value of button
lcd.setCursor(12,1);
lcd.print(adc_key_in);
}
lcd.setCursor(0,1); // move to the begining of the second line
switch (lcd_key) // depending on which button was pushed, we perform an action
{
case btnRIGHT:
{
lcd.print("RIGHT ");
break;
}
case btnLEFT:
{
lcd.print("LEFT ");
break;
}
case btnUP:
{
lcd.print("UP ");
break;
}
case btnDOWN:
{
lcd.print("DOWN ");
break;
}
case btnSELECT:
{
lcd.print("SELECT");
break;
}
case btnNONE:
{
lcd.print("NONE ");
break;
}
}/* --(end switch )-- */
}/* --(end main loop )-- */
/*-----( Declare User-written Functions )-----*/
int read_LCD_buttons()
{
adc_key_in = analogRead(0); // read the value from the sensor
delay(5); //switch debounce delay. Increase this delay if incorrect switch selections are returned.
int k = (analogRead(0) - adc_key_in); //gives the button a slight range to allow for a little contact resistance noise
if (5 < abs(k)) return btnNONE; // double checks the keypress. If the two readings are not equal +/-k value after debounce delay, it tries again.
// my buttons when read are centered at these valies: 0, 144, 329, 504, 741
// we add approx 50 to those values and check to see if we are close
if (adc_key_in > 1000) return btnNONE; // We make this the 1st option for speed reasons since it will be the most likely result
if (adc_key_in < 50) return btnRIGHT;
if (adc_key_in < 195) return btnUP;
if (adc_key_in < 380) return btnDOWN;
if (adc_key_in < 555) return btnLEFT;
if (adc_key_in < 790) return btnSELECT;
return btnNONE; // when all others fail, return this...
}
