MTanalogButtons, Test 1
Event management for Uno, Nano, Mega

Testing the CAN with two analog pins

When using a single analog pin, once the voltage is established for a button, it will not change. When using two pins analog, the multiplexer will switch from one voltage to another before making the conversion. The following program uses two MTanalogButtons which are read alternately. When a button is pressed, the voltage measured for the first is between 0V and 1.1V, and the second imposes a voltage of 5V at the CAN input. So we go from one side of the tensions to the other. I don't see any errors reading.

Complete program example

// This program checks that an analog reading on another analog pin does not
// disturb the measurement
// As we use a single ADC with a multiplexer, it is necessary to check that
// in moving from one pin to another, we can read well
//
// Here, we will read a keypad with pin A5 and set pin A0 to 5V.
// As we have two MTanalogButtons, we will alternately read A5 and A0
// Before reading the buttons, we will therefore read a 5V.

#include <MTobjects.h> // V1.1.1 See http://arduino.dansetrad.fr/en/MTobjects


const byte PIN_1 = A5;
const byte PIN_2 = A0; // Pin A0 is at 5V
const word THRESHOLDS_TABLE[] = {982, 920, 880, 840, 797, 754, 710, 665, 619, 571, 523, 471, 421, 369, 316, 260, 204, 145, 87, 28, 0}; // Values of comparison thresholds

void press(byte key)
{ 
  Serial.print("Key #"); 
  Serial.print(key); 
  Serial.print(" just pressed ");
}

void release(void)
{ 
  Serial.println("and released"); 
}

MTanalogButtons Keypad1(PIN_1, THRESHOLDS_TABLE, press, release); // The one we observe
MTanalogButtons Keypad2(PIN_2, THRESHOLDS_TABLE); // Will force readings to 1024


void setup()
{ 
  Serial.begin(115200); // Also set the console to 115200 baud!
  analogReference(INTERNAL); // We thus go back and forth on the ADC between 5V and a low voltage if we press a button
  Serial.println("Press keys");
}

void loop(){}