Bluetooth Based Temperature Meter Project using Microcontroller and MikroC USART Terminal

In this project , we will measure surroundings temperature and it will be shown at MikroC USART Terminal . First of all we need to set up LM35  sensor with pic microcontroller and an ADC register will take data from the temperature sensor . After calculating the temperature in centigrade  it will be sent to  our computer's MikroC USART terminal through Bluetooth[HC-06] . That is the basic concepts of this project.

Bluetooth Based Temperature Meter Project using Microcontroller

We will need an ADC Converter so that microcontroller can read the temperature .

ADC [Analog to Digital Converter]:

ADCON1 Register

Basically ADC is like as voltage divider . According to voltage It produce output .
bit 5 : VCFG0: Voltage Reference Configuration bit (VREF- source)
1 = VREF- (AN2)
0 = VSS or 0 volt

bit 4 :VCFG0: Voltage Reference Configuration bit (VREF+ source)
1 = VREF+ (AN3)
0 = VDD or 5volt

We will set  VCFG0[bit 5]=0and VCFG0[bit4]=0 . So we will get highest value 5volt[1023] and lowest value 0volt[0].The ADCON1 is a 10 bit register that means  (2 to the power 10) is it's highest counting capacity and the result is 1024 . So this register can count from 0 to 1023 . When 0 volt , we get reading at RA0 pin  0 .When 5 volt , we get reading at RA0 pin 1023. It means 5volt equivalent to 1023 .

 If  1023 reading value    equal   to 5 volt.
So 1      reading value    equal   to  5/1023 volt
So 'read_val'  reading  value   equal  to (5/1023)*read_val .volt .
As we know LM35 reading can be changed  with  0.01 v per degree centigrade change , the temperature calculation should be like that :
    0.01 volt   for     1      degree centigrade Temperature
so  1     ,,       ,,  (1/0.01)   ,,         ,,              ,,

and (5/1023)*read_val    volt    for  [{(5/1023)*read_val }/0.01]  degree centigrade Temperature .

Mikro C Library Funtions :

UARTx_Init:  This function will initialize USART option of  Microcontroller with Baud rate . We will use baud rate 38400 . The code will be look like this :

 UART1_Init(38400);

UARTx_Data_Ready: This will check if it is available to read or transmit data .

UARTx_Read_Text: To read text data .Look at the example .

if (UART1_Data_Ready() == 1) {

UART1_Read_Text(  txt,  ")" , 13); }

This is checking if data is available to read . ")" means , txt car array variable will be being stored until the ")" will found . 13 means to try for 13 times . So , i think our text should not be longer than 11 character .

UARTx_Write_Text: This will send text data . Look at the example :

if (UART1_Tx_Idle() == 1) {// this will check , if the last data transmission is completed

 UART1_Write_Text("button2");
 }

Recommended: How to Interface Bluetooth Module (HC-06) with PIC Microcontroller [Step by Step Picture]

Circuit :

Bluetooth Based Temperature Meter Project using Microcontroller and MikroC USART Terminal

Source Code :

 char txt[8];  
 double chk;  
 int i=0,ckop=0;  
 void main() {  
 ADCON1=0x0E;         // Configure RE1 pin as input  
 CMCON=7;  
 for(i=0;i<16;i++){txt[i]=' ';}  
   TRISA.F3=1;  
    TRISA.F4=1;        // Initialize ADC  
 Adc_Init();  
   UART1_Init(38400);  
      delay_ms(200);            // Initialize LCD  
  while(1){  
  chk=Adc_Read(0);  
  chk=(chk*5)/1023;  
  chk=chk/0.01;  //10mV == 1 degree
  inttostr(chk,txt);  
  UART1_Write_Text(" Temperature:");  
  UART1_Write_Text(txt);  
  UART1_Write_Text(" \n");  
  delay_ms(6000);  
 }  
 }  

Result:

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Thank You!