2.5 Foundation Drivers: UART - All example snippets

Video demonstrating how to use the various UART code snippets.

Getting Started Topics

Video: Foundation Drivers - UART all example snippets

uart_example.c

/**
\file
\brief This file contains sample source codes to demonstrate the UART Foundation Services APIs.

For this example application to work the following needs to be done:
    1. Configure the EUSART module as follows:
        - Enable EUSART: ticked
        - Enable Transmit: ticked
        - Enable Receive: ticked
        - Enable EUSART Interrupts: ticked
        - Redirect STDIO to USART: ticked
        - Configure other settings as desired.
        - Select TX and RX pins in Pin Manager: Grid View.
    2. Connect the board to a laptop serial port.
    3. Open a serial port terminal application (i.e. PuTTY or TeraTerm)
    4. Configure the serial port application to the following settings:
        - Baud Speed: same as the UART configuration
        - Data: same as the UART configuration
        - Parity: none
        - Stop bits: same as the UART configuration
        - Flow control: none
        - Receive: Carriage Return
        - Transmit: Carriage Return
        - Local Echo: On
    5. Call UART_example_<USE_CASE>() from main().   

This example works like this:
    1. Upon reset, the application will display "START" to test UART_Write function.
    2. The program will then print the following to test printf support:
        <br>Hello World! 1
        <br>Hello World! 2
        <br>Hello World! 3
    3. The program will then display "Type a message then press enter (max 16 chars):"
    4. Type a message no longer than 16 characters.
    5. The program will then print "You typed:" and echo back your message. This will ensure that the UART_Read function is working.
    6. If everything is working fine, the program will print "OK."

Note: To test other instances, feel free to modify this file.
\copyright (c) 2020 Microchip Technology Inc. and its subsidiaries.
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    software and any derivatives exclusively with Microchip products.

    THIS SOFTWARE IS SUPPLIED BY MICROCHIP "AS IS". NO WARRANTIES, WHETHER
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    WHATSOEVER RELATED TO THE SOFTWARE, HOWEVER CAUSED, EVEN IF MICROCHIP HAS
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*/

#include "../drivers/uart.h" 
#include "uart_example.h"
#include <string.h>
#include <stdio.h>

static uint8_t rx[16];
const char * string = "Transmit test\n";

/**
Call this function from main to send a string of characters. This can be a light-weight alternative to printf, e.g. for a string of ASCII characters.
@param none
*/
void UART_example_WRITE_STRING(char *str)
{
    uint8_t count = 0; 
	
    while (count < strlen(str)){
        uart[UART1].Write(str[count]);
        count++;
    }   
}
/**
Call this function from main to print to a terminal a string with a uint8_t variable
@param none
*/
void UART_example_PRINTF(void)
{
    uint8_t count = 0;
    
    while (++count<4)
        printf("Hello World! %d\n",count);
}
/**
Call this function in main() to type a message into a serial terminal for the program to echo back what you typed. 
@param none
 */
void UART_example_READ(void)
{
    printf("Receive test: Type a message then press enter (max 16 chars):");
    
    //Wait until data is ready
    while(uart[UART1].DataReady()==0){
        ;
    }

    
    //Receive the typed word/information
    int index = 0;
    
    memset(rx, 0, sizeof(rx));
    for (int i = 0; i < sizeof(rx); i++) {
	rx[i] = uart[UART1].Read(); // Blocks until character is available
        if (rx[i] == '\n'){ 
            index = i;
            break;
        }
    }
    
    //Echo back the information
    printf("You typed: ");
    for (int i = 0; i < index; i++) {
	printf("%c",rx[i]);
    }
}
/**
Call this function in main() to sequentially run
@param none
 */
void UART_example_RUNALL(void)
{   
    // Test UART Write/Transmit functionality
    UART_example_WRITE_STRING(string);

    // Test printf() support
    UART_example_PRINTF();

    // Test UART Read/Receive functionality
    UART_example_READ();

    // If we get here, everything was OK
    printf("\nok");
}
/**
 End of File
 */