Termometru dublu si indicator tensiune baterie cu ATtiny85 pe afisaj LCD1602

   Daca am putut face cu microcontroleul ATtiny85 un termometru dublu cu afisare pe ecran alfanumeric LCD1602 prin intermediul unui registru de deplasare 74HC595, m-am gandit ca pot sa am si indicarea tensiunii bateriei unei masini si astfel sa am indicatii despre temperatura din exterior si cea din interior, asta daca pot folosi pinul fizic 1, RESET, dar si ADC0 (A0), dupa cum e prezentat pe site-ul http://www.pighixxx.com/

   In cel mai rau caz, voi renunta la temperatura din interior...
   Schema gandita de mine deriva din cea a termometrului dublu la care am adaugat un divizor rezistiv cu raport de 1:4 (tensiune maxima de intrare de 20V), cum am facut la indicarul starii bateriei masinii cu led multicolor.

   Trebuie sa schimb pictogramele, iar afisarea sa fie ceva de genul:

    Pictogramele vor fi de genul:

- baterie: 

- temperatura interior (masina):

- temperatura exterior (un copac):

   Sketch-ul pe care l-am gandit si de care am fost multumit:

/*
this sketch is adapted by niq_ro from
http://www.tehnic.go.ro
http://www.niqro.3x.ro
http://nicuflorica.blogspot.ro/
http://arduinotehniq.blogspot.com/
for made a dual thermometer & battery status for car with ATtiny85 as Arduino..

 * 3-pin Arduino interface for HD44780 LCDs via 74HC595 Shift Register
 *     by Rowan Simms   code@rowansimms.com
 *     License: Creative Commons - Attribution.
 *     Full Documentation and Description:  http://rowansimms.com/article.php/lcd-hookup-in-seconds
 *
 * This sketch allows Arduinos to use a shift register to control an LCD, allowing 
 * a reduction in pins it requires from 6 to 3 while still retaining full control
 * including backlight on/off.
 * This requires the use of the LiquidCrystal595 library
 * available at: http://code.google.com/p/arduino-lcd-3pin/
 */

#include <LiquidCrystal595.h>    // include the library
LiquidCrystal595 lcd(0,1,2);     // datapin, latchpin, clockpin

byte baterie1[8] = {
  B00000,
  B01100,
  B11111,
  B10000,
  B10000,
  B10000,
  B10000,
  B11111,
};

byte baterie2[8] = {
  B00000,
  B00110,
  B11111,
  B00001,
  B00001,
  B00001,
  B00001,
  B11111,
};

byte masina1[8] = {
  B00111,
  B01000,
  B01111,
  B10110,
  B10000,
  B11111,
  B01100,
  B01100
};

byte masina2[8] = {
  B11100,
  B00010,
  B11110,
  B01101,
  B00001,
  B11111,
  B00110,
  B00110
};


byte grad[8] = {
  B01110,
  B10001,
  B10001,
  B01110,
  B00000,
  B00000,
  B00000,
};

byte pom1[8] = {
  B00111,
  B01000,
  B10101,
  B10010,
  B10000,
  B01111,
  B00001,
  B00001
};

byte pom2[8] = {
  B11000,
  B00110,
  B10101,
  B01001,
  B00010,
  B11100,
  B10000,
  B10000
};



// variables 
// variabile 
int t1, t2;
float t10, t20;
float t11, t21;
float t12, t22;


int temperaturePin1 = A0; // output from first LM335 is put at analog input no.0
int temperaturePin2 = A3; // output from second LM335 is put at analog input no.1
// cei 2 senzori de temperaturia LM335 sunt legati la pinii A0 si A1

int divbaterie = A2; //the input pin for voltage divider
int u = 0;  // variable to store the value coming from the sensor
float k=4.90/5; // corection voltage (real voltage after 7805 output)
float k1 = k; // real divider correction

float u1 = 0; // voltage on battery
float divizor = 0.25; // divider raport

void setup() {
    lcd.begin(16,2);             // 16 characters, 2 rows
  lcd.createChar(0, grad);
  lcd.createChar(1, baterie1);
  lcd.createChar(2, baterie2);
  lcd.createChar(3, masina1);
  lcd.createChar(4, masina2);
  lcd.createChar(5, pom1);
  lcd.createChar(6, pom2);


 lcd.clear(); // clear the screen
 lcd.setCursor(2, 0); // put cursor at colon 2 and row 0 = left/up
 lcd.print("ATtiny85 dual"); // print a text
 lcd.setCursor(2, 1); // put cursor at colon 0 and row 0 = left/down
 lcd.print("thermometer +"); // print a text
 delay (3000);
 lcd.clear(); // clear the screen

 lcd.setCursor(0, 0); // put cursor at colon 2 and row 0 = left/up
 lcd.print("+ battery status"); // print a text
 lcd.setCursor(4, 1); // put cursor at colon 0 and row 0 = left/down
 lcd.print("by niq_ro"); // print a text
 delay (3000);
 lcd.clear(); // clear the screen

}


void loop() {

  // Read and store Sensor Data
t11=0;
t21=0;
//lcd.clear(); // clear the screen

for (int x=1; x <= 5; x++)
  {
// calculate the value  
t1 = analogRead(temperaturePin1); // read value from temperature from first sensor (LM335);
 t10 = 100.0*(k*5.0*t1/1023-2.980)+25.0;
 t11 = t10 + t11;

t2 = analogRead(temperaturePin2); // read value from temperature from second sensor (LM335);
 t20 = 100.0*(k*5.0*t2/1023-2.980)+25.0;
 t21 = t20 + t21;

delay (500);
  }   

t12 = t11/5.0 -1.5 ; // average and corrected temperature  
t22 = t21/5.0 -1.0; // average and corrected temperature  

    lcd.setCursor(0, 0);
    lcd.write(byte(3));
    lcd.write(byte(4));
    lcd.print(":");
  //  lcd.print("t1="); 
    if (t12<10) lcd.print(" "); 
    if (t12>0.0) lcd.print("+"); 
    lcd.print(t12,1);
  //  lcd.write(0b11011111);
  lcd.write(byte(0));
    lcd.print("C ");
  
  
    lcd.setCursor(0, 1);
//   lcd.print("ext:");
  //  lcd.print("t2="); 
    lcd.write(byte(5));
    lcd.write(byte(6));
lcd.print(":");
    if (t22<10) lcd.print(" "); 
    if (t22>0.0) lcd.print("+"); 
    lcd.print(t22,1);
   // lcd.write(0b11011111);
   lcd.write(byte(0));
    lcd.print("C ");


 // read the value from the sensor:
  u = analogRead(divbaterie);      

u1 = k1*5.0*u/1023.0; // conver ADC in voltage value
u1 = u1/divizor+0.05;

lcd.setCursor(14, 0);
lcd.write(byte(1));
lcd.write(byte(2));
lcd.setCursor(11, 1);
  if (u1<10) lcd.print(" "); 
  lcd.print(u1,1);
  lcd.print("V"); 
}

   Ca marime, el nu este foarte mare fata de cel care avea doar termometru dublu:

   Am realizat montajul si am comparat cu un multimetru:

   Ca de obicei, am facut un filmulet.. numit termometru dublu cu indicare stare acumulator masina cu ATtiny85