dsPIC30F2010 SPI Display 5VDC DVM using MikroC

In previous example, I use the SPI module of the dsPIC30F2010 to control a serial LED display and seven-segment display. Now let put them together making a serial display digital volt-meter.

 

ADC Reading 

 

There is one on-board POT so I use it to adjust input voltage that varies between 0 and +5VDC. It will show the reading voltage on a serial seven-segment display.

Schematic: 

Schematic Diagram

This is just schematic using device symbols. I can not be simulated like other build-in models. I download the dsPIC30F2010 symbol from SnapEDA for free. 

 

MikroC Source Code: 

1. 
   
2. // Chip Select Pin
3. sbit Chip_Select at LATE3_bit;
4. sbit Chip_Select_Direction at TRISE3_bit;
5. 
   
6. void SN74595_Send(char _data){
7. SPI_Write(_data); // Send high byte via SPI
8. Chip_Select = 0; // Select SPI chip
9. Chip_Select = 1; // Deselect SPI chip
10. }
11. 
    
12. // Common Cathod Segment Data
13. const char cc[16]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,
14. 0x7F,0x6F,0x77,0x7C,0x58,0x5E,0x79,0x71};
15. 
    
16. void show_number(char number){
17. SN74595_Send(~cc[number]);
18. }
19. 
    
20. 
    
21. 
    
22. void main() {
23. unsigned int temp_res;
24. float voltage=0;
25. char digit=0;
26. Chip_Select = 1; // Deselect DAC
27. Chip_Select_Direction = 0; // Set CS# pin as Output
28. SPI1_Init(); // Initialize SPI module
29. TRISB = 0xFFFF; // PORTB is input
30. TRISD = 0; // PORTD is output
31. TRISF = 0; // PORTF is output
32. ADC1_Init(); // Enable ADC module
34. while(1){
35. temp_res = ADC1_Read(4); // Get 10-bit results of AD conversion
36. voltage = (5.0 * temp_res)/1023;
37. digit = (char)voltage;
38. show_number(digit);
39. Delay_ms(500);
40. }
41. 
    
42. }

 
Using a 0.5 second delay time making the display run very smooth without glitching. It could saves the power consumption since the ADC reading is not so frequently. For more information about using the ADC please read this post.

 

Zero Volt ADC Reading

3 Volt ADC Reading

5 Volt ADC Reading

 I test example using my DIY dsPIC30F1010 Prototype Board. For more information about this PCB see this post.