Juan Angel García / Mbed 2 deprecated 7_6

I2C slave

Dependencies:   mbed

main.cpp@0:09c1e7c28d04, 2017-03-07 (annotated)

Committer:
jangelgm
Date:
Tue Mar 07 11:36:12 2017 +0000
Revision:
0:09c1e7c28d04
I2C slave

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jangelgm 0:09c1e7c28d04 1 /*Program Example 7.6: I2C Slave, when called transfers switch state to mbed acting as
jangelgm 0:09c1e7c28d04 2 Master, and displays state of Master’s switches on its leds.
jangelgm 0:09c1e7c28d04 3 */
jangelgm 0:09c1e7c28d04 4 #include <mbed.h>
jangelgm 0:09c1e7c28d04 5 I2CSlave slave(p9, p10); //Configure I2C slave
jangelgm 0:09c1e7c28d04 6 DigitalOut red_led(p25); //red led
jangelgm 0:09c1e7c28d04 7 DigitalOut green_led(p26); //green led
jangelgm 0:09c1e7c28d04 8 DigitalIn switch_ip1(p5);
jangelgm 0:09c1e7c28d04 9 DigitalIn switch_ip2(p6);
jangelgm 0:09c1e7c28d04 10
jangelgm 0:09c1e7c28d04 11 char switch_word ; //word we will send
jangelgm 0:09c1e7c28d04 12 char recd_val; //value received from master
jangelgm 0:09c1e7c28d04 13
jangelgm 0:09c1e7c28d04 14 int main()
jangelgm 0:09c1e7c28d04 15 {
jangelgm 0:09c1e7c28d04 16 slave.address(0x52);
jangelgm 0:09c1e7c28d04 17 while (1) {
jangelgm 0:09c1e7c28d04 18 //set up switch_word from switches that are pressed
jangelgm 0:09c1e7c28d04 19 switch_word=0xa0; //set up a recognizable output pattern
jangelgm 0:09c1e7c28d04 20 if (switch_ip1==1)
jangelgm 0:09c1e7c28d04 21 switch_word=switch_word | 0x01;
jangelgm 0:09c1e7c28d04 22 if (switch_ip2==1)
jangelgm 0:09c1e7c28d04 23 switch_word=switch_word | 0x02;
jangelgm 0:09c1e7c28d04 24 slave.write(switch_word); //load up word to send
jangelgm 0:09c1e7c28d04 25 //test for I2C, and act accordingly
jangelgm 0:09c1e7c28d04 26 int i = slave.receive();
jangelgm 0:09c1e7c28d04 27 if (i == 3)
jangelgm 0:09c1e7c28d04 28 {
jangelgm 0:09c1e7c28d04 29 //slave is addressed, Master will write
jangelgm 0:09c1e7c28d04 30 recd_val= slave.read();
jangelgm 0:09c1e7c28d04 31 //now set leds according to received word
jangelgm 0:09c1e7c28d04 32 red_led=0; //preset both to 0
jangelgm 0:09c1e7c28d04 33 green_led=0;
jangelgm 0:09c1e7c28d04 34 recd_val=recd_val & 0x03; //AND out unwanted bits
jangelgm 0:09c1e7c28d04 35 if (recd_val==1)
jangelgm 0:09c1e7c28d04 36 red_led=1;
jangelgm 0:09c1e7c28d04 37 if (recd_val==2)
jangelgm 0:09c1e7c28d04 38 green_led=1;
jangelgm 0:09c1e7c28d04 39 if (recd_val==3)
jangelgm 0:09c1e7c28d04 40 {
jangelgm 0:09c1e7c28d04 41 red_led=1;
jangelgm 0:09c1e7c28d04 42 green_led=1;
jangelgm 0:09c1e7c28d04 43 }
jangelgm 0:09c1e7c28d04 44 }
jangelgm 0:09c1e7c28d04 45 }
jangelgm 0:09c1e7c28d04 46 }