Juan Angel García
/
7_6
I2C slave
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?
User | Revision | Line number | New 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 | } |