Using LCD display

This example illustrates the use of an alphanumeric LCD display. The function libraries simplify this program, which means that the effort made to create software pays off in the end. A message written in two lines appears on the display: mikroElektronika LCD example Two seconds later, the message in the second line is changed and displays voltage present on the A/D converter input (the RA2 pin). For example: mikroElektronika voltage:3.141V In true device, the current temperature or some other measured value can be displayed instead of voltage. In order to make this example work properly, it is necessary to tick off the following libraries in the Library Manager prior to compiling:

• ADC
• LCD

/*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);
 }
}