dsPIC30F2010 MikroC for dsPIC UART Example

Overview

The UART is a simple serial communication interface exists in most of micro-controllers. Its protocol is very simple. A build-in UART module of a micro-controller offer a high speed, configurable and reliable data communication. This module doesn't exist in some low-end 8-bit micro-controller for example the PIC16F54 or the popular PIC16F84A. However the programmer can emulate this communication protocol in firmware such Assembly or even embedded C programming language (Software UART) due to its clarity. Some C compilers have their software UART allowing the user access to their build-in function libraries.

 

UART Received ASCII Data

 

This communication interface is used to interact between micro-controller to microcontroller due to its two data wire - Transmit (TX) and Receive (RX). Some peripheral device such as GSM module, Wi-Fi modem (ESP8266), or HMI use UART.

 

MikroC for dsPIC UART Library

MikroC has built-in UART library that supports both hardware and software UART. Hardware UART implements the internal dedicated UART modules of any 16-bit PIC micro-controllers. Some 16-bit PIC micro-controllers have more than one UART interface, UART1, UART2, etc.

These are MikroC Hardware UART Library Routines:

Library Routines

• UARTx_Init
• UARTx_Init_Advanced
• UARTx_Data_Ready
• UARTx_Tx_Idle
• UARTx_Read
• UARTx_Read_Text
• UARTx_Write
• UARTx_Write_Text
• UART_Set_Active

Generic Routines

• UART_Data_Ready
• UART_Tx_Idle
• UART_Read
• UART_Read_Text
• UART_Write
• UART_Write_Text

 

Now let test the UART1 communication interface of the dsPIC30F2010 using the MikroC UART example.

MikroC Source Code:

1. 
   
2. char uart_rd;
3. 
   
4. void main() {
5. 
   
6. UART1_Init(9600); // Initialize UART module at 9600 bps
7. Delay_ms(100); // Wait for UART module to stabilize
8. 
   
9. // U1MODEbits.ALTIO = 1; // Un-comment this line to have Rx and Tx pins on their alternate
10. // locations. This is used to free the pins for other module, namely the SPI.
11. 
    
12. UART1_Write_Text("Start");
13. UART1_Write(10);
14. UART1_Write(13);
15. 
    
16. while (1) { // Endless loop
17. if (UART1_Data_Ready()) { // If data is received,
18. uart_rd = UART1_Read(); // read the received data,
19. UART1_Write(uart_rd); // and send data via UART
20. }
21. }
22. }

 

In the Library Manger Window, Tick on UART. Then build the source code.

 

UART in Library Manager

 

In MikroC IDE, go to Tools -> USART Terminal to open the interface.

 

USART Terminal

 

Enter any characters and click Send, then the MCU will send back the received data. UART requires a precise micro-controller timing. So don't forget to set a correct clock source and frequency.

Let put a character LCD that displays received ASCII characters from PC Serial Port Terminal.

MikroC Source Code:

1. // LCD module connections
2. sbit LCD_RS at LATE0_bit;
3. sbit LCD_EN at LATE1_bit;
4. sbit LCD_D4 at LATE2_bit;
5. sbit LCD_D5 at LATE3_bit;
6. sbit LCD_D6 at LATE4_bit;
7. sbit LCD_D7 at LATE5_bit;
8. 
   
9. sbit LCD_RS_Direction at TRISE0_bit;
10. sbit LCD_EN_Direction at TRISE1_bit;
11. sbit LCD_D4_Direction at TRISE2_bit;
12. sbit LCD_D5_Direction at TRISE3_bit;
13. sbit LCD_D6_Direction at TRISE4_bit;
14. sbit LCD_D7_Direction at TRISE5_bit;
15. // End LCD module connections
16. 
    
17. char txt1[] = "dsPIC30F2010";
18. char txt2[] = "UART Example";
19. char txt3[] = "Lcd4bit";
20. char txt4[] = "example";
21. 
    
22. char i=1;
23. char uart_rd;
24. 
    
25. void main(){
26. ADPCFG = 0xFFFF; // Configure AN pins as digital I/O
27. 
    
28. Lcd_Init(); // Initialize LCD
29. UART1_Init(9600); // Initialize UART module at 9600 bps
30. Delay_ms(100); // Wait for UART module to stabilize
31. UART1_Write_Text("Reply for dsPIC30F2010 MCU");
32. UART1_Write(10);
33. UART1_Write(13);
35. Lcd_Cmd(_LCD_CLEAR); // Clear display
36. Lcd_Cmd(_LCD_CURSOR_OFF); // Cursor off
37. Lcd_Out(1,3,txt1); // Write text in first row
38. 
    
39. Lcd_Out(2,3,txt2); // Write text in second row
40. Delay_ms(5000);
41. 
    
42. Lcd_Cmd(_LCD_CLEAR); // Clear display
43. Delay_ms(10);
44. Lcd_Out(1, 1 ,"PC Terminal:");
45. 
    
46. while(1) { // Endless loop
47. if (UART1_Data_Ready()) { // If data is received,
48. uart_rd = UART1_Read(); // read the received data,
49. UART1_Write(uart_rd); // and send data via UART
50. Lcd_Chr(2, i, uart_rd);
51. i++;
52. }
53. if(i>15) {
54. i = 1;
55. Lcd_Cmd(_LCD_CLEAR);
56. Delay_ms(10);
57. Lcd_Out(1 ,1 ,"PC Terminal:");
58. }
59. }
60. }

 

The LCD shows UART characters, and the MCU will clears it automatically whenever the UART receiving counts reach 15.

Schematic:

Schematic Diagram in Proteus

dsPIC30F2010 Prototype Board Testing:

 

Serial Port Terminal

 

Testing Program

 

UART ASCII Data Receiving