lambda meter problem

[dope40]

Thanks , but i know the formula ... i dont know how to write it in C so i can use it on the PIC

 

[dope40]

Hi , i found this voltmeter code , so can i somehow remake it so it shows the equation result instead of the voltage?

/*Header******************************************************/

// LCD module connections
sbit LCD_RS at RB4_bit;
sbit LCD_EN at RB5_bit;
sbit LCD_D4 at RB0_bit;
sbit LCD_D5 at RB1_bit;
sbit LCD_D6 at RB2_bit;
sbit LCD_D7 at RB3_bit;
sbit LCD_RS_Direction at TRISB4_bit;
sbit LCD_EN_Direction at TRISB5_bit;
sbit LCD_D4_Direction at TRISB0_bit;
sbit LCD_D5_Direction at TRISB1_bit;
sbit LCD_D6_Direction at TRISB2_bit;
sbit LCD_D7_Direction at TRISB3_bit;
// End LCD module connections

unsigned char ch;                    //
unsigned int adc_rd;                 // Declare variables
char *text;                          //
long tlong;                          //

void main() {
    INTCON = 0;                      // All interrupts disabled
    ANSEL = 0x04;                    // Pin RA2 is configured as an analog input
    TRISA = 0x04;
    ANSELH = 0;                      // Rest of pins are configured as digital
    
    Lcd_Init();                      // LCD display initialization
    Lcd_Cmd(_LCD_CURSOR_OFF);        // LCD command (cursor off)
    Lcd_Cmd(_LCD_CLEAR);             // LCD command (clear LCD)
    
    text = "mikroElektronika";       // Define the first message
    Lcd_Out(1,1,text);               // Write the first message in the first line
    text = "LCD example";            // Define the second message
    Lcd_Out(2,1,text);               // Define the first message
    
    ADCON1 = 0x82;                   // A/D voltage reference is VCC
    TRISA = 0xFF;                    // All port A pins are configured as inputs
    Delay_ms(2000);
    
    text = "voltage:";               // Define the third message
    
    while (1) {
        adc_rd = ADC_Read(2);        // A/D conversion. Pin RA2 is an input.
        Lcd_Out(2,1,text);           // Write result in the second line
        tlong = (long)adc_rd * 5000; // Convert the result in millivolts
        tlong = tlong / 1023;        // 0..1023 -> 0-5000mV
        ch = tlong / 1000;           // Extract volts (thousands of millivolts)
                                     // from result
        Lcd_Chr(2,9,48+ch);          // Write result in ASCII format
        Lcd_Chr_CP('.');
        ch = (tlong / 100) % 10;     // Extract hundreds of millivolts
        Lcd_Chr_CP(48+ch);           // Write result in ASCII format
        ch = (tlong / 10) % 10;      // Extract tens of millivolts
        Lcd_Chr_CP(48+ch);           // Write result in ASCII format
        ch = tlong % 10;             // Extract digits for millivolts
        Lcd_Chr_CP(48+ch);           // Write result in ASCII format
        Lcd_Chr_CP('V');
        Delay_ms(1);
    }
}