Juan Angel García / Mbed 2 deprecated 7_9

UART

Dependencies:   mbed

main.cpp@0:4ec99b800425, 2017-03-07 (annotated)

Committer:
jangelgm
Date:
Tue Mar 07 11:38:01 2017 +0000
Revision:
0:4ec99b800425
UART

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jangelgm 0:4ec99b800425 1 /*Program Example 7.9: Sets the mbed up for async communication, and exchanges data with
jangelgm 0:4ec99b800425 2 a similar node, sending its own switch positions, and displaying those of the other.
jangelgm 0:4ec99b800425 3 */
jangelgm 0:4ec99b800425 4 #include "mbed.h"
jangelgm 0:4ec99b800425 5 Serial async_port(p9, p10); //set up TX and RX on pins 9 and 10
jangelgm 0:4ec99b800425 6
jangelgm 0:4ec99b800425 7 DigitalOut red_led(p25); //red led
jangelgm 0:4ec99b800425 8 DigitalOut green_led(p26); //green led
jangelgm 0:4ec99b800425 9 DigitalOut strobe(p7); //a strobe to trigger the scope
jangelgm 0:4ec99b800425 10
jangelgm 0:4ec99b800425 11 DigitalIn switch_ip1(p5);
jangelgm 0:4ec99b800425 12 DigitalIn switch_ip2(p6);
jangelgm 0:4ec99b800425 13
jangelgm 0:4ec99b800425 14 char switch_word ; //the word we will send
jangelgm 0:4ec99b800425 15 char recd_val; //the received value
jangelgm 0:4ec99b800425 16
jangelgm 0:4ec99b800425 17 int main()
jangelgm 0:4ec99b800425 18 {
jangelgm 0:4ec99b800425 19 async_port.baud(9600); //set baud rate to 9600 (ie default)
jangelgm 0:4ec99b800425 20 //accept default format, of 8 bits, no parity
jangelgm 0:4ec99b800425 21 while (1) {
jangelgm 0:4ec99b800425 22 //Set up the word to be sent, by testing switch inputs
jangelgm 0:4ec99b800425 23 switch_word=0xa0; //set up a recognizable output pattern
jangelgm 0:4ec99b800425 24 if (switch_ip1==1)
jangelgm 0:4ec99b800425 25 switch_word=switch_word | 0x01; //OR in lsb
jangelgm 0:4ec99b800425 26 if (switch_ip2==1)
jangelgm 0:4ec99b800425 27 switch_word=switch_word | 0x02; //OR in next lsb
jangelgm 0:4ec99b800425 28 strobe =1; //short strobe pulse
jangelgm 0:4ec99b800425 29 wait_us(10);
jangelgm 0:4ec99b800425 30 strobe=0;
jangelgm 0:4ec99b800425 31 async_port.putc(switch_word); //transmit switch_word
jangelgm 0:4ec99b800425 32 if (async_port.readable()==1) //is there a character to be read?
jangelgm 0:4ec99b800425 33 recd_val=async_port.getc(); //if yes, then read it
jangelgm 0:4ec99b800425 34 red_led=0; //preset both to 0
jangelgm 0:4ec99b800425 35 green_led=0;
jangelgm 0:4ec99b800425 36 recd_val=recd_val & 0x03; //AND out unwanted bits
jangelgm 0:4ec99b800425 37 if (recd_val==1)
jangelgm 0:4ec99b800425 38 red_led=1;
jangelgm 0:4ec99b800425 39 if (recd_val==2)
jangelgm 0:4ec99b800425 40 green_led=1;
jangelgm 0:4ec99b800425 41 if (recd_val==3) {
jangelgm 0:4ec99b800425 42 red_led=1;
jangelgm 0:4ec99b800425 43 green_led=1;
jangelgm 0:4ec99b800425 44 }
jangelgm 0:4ec99b800425 45 }
jangelgm 0:4ec99b800425 46 }