Use LCD display

This example illustrates the use of an alphanumeric LCD display. The function libraries make this program simpler. Two messages written in two lines appear on the display: mikroElektronika LCD example Two seconds later, the second message is replaced with the voltage present on the A/D converter input (the RA2 pin). For example: mikroElektronika voltage:3.141V Anyway, 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 check the following libraries in the Library Manager prior to compiling:

• ADC
• LCD

'Header******************************************************
program example_10 ' Program name

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

dim text as string [16] ' Variable text is of string type
dim ch, adc_rd as word ' Variables ch and adc_rd are of word type
dim tlong as longword ' Variable tlong is of longword type

main: ' Start of program
TRISB = 0 ' All port PORTB pins are configured as outputs
PORTB = 0xFF
INTCON = 0 ' All interrupts disabled
ANSEL = 0x04 ' Pin RA2 is configured as an analog input
TRISA = 0x04
ANSELH = 0 ' Rest of pins is 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) ' Write the second message in the second line

ADCON1 = 0x80 ' A/D voltage reference is VCC
TRISA = 0xFF ' All PORTA pins are configured as inputs
Delay_ms(2000)
text = "Voltage=" ' Define the third message

while 1 ' Endless loop
 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 = adc_rd * 5000 ' Convert the result in millivolts
 tlong = tlong / 1023 ' 0..1023 -> 0-5000mV
 ch = (tlong / 1000) mod 10 ' Extract volts (thousands of millivolts)
 ' from result
 Lcd_Chr(2,9,48+ch) ' Write result in ASCII format
 Lcd_Chr_CP(".") ' Write the decimal pint
 ch = (tlong / 100) mod 10 ' Extract hundreds of millivolts
 Lcd_Chr_CP(48+ch) ' Write result in ASCII format
 ch = (tlong / 10) mod 10 ' Extract tens of millivolts
 Lcd_Chr_CP(48+ch) ' Write result in ASCII format
 ch = tlong mod 10 ' Extract digits for millivolts
 Lcd_Chr_CP(48+ch) ' Write result in ASCII format
 Lcd_Chr_CP("V") ' Write a mark for voltage "V"
 Delay_ms(1) ' 1mS delay
wend

end. ' End of program