Juan Angel García
/
7_9
UART
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?
User | Revision | Line number | New 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 | } |