I2C Slave device. Mimics the 24LC256 in a very limited way (no addressing)
Fork of I2CSlave by
main.cpp@3:1bb80997f316, 2013-08-29 (annotated)
- Committer:
- Kit1
- Date:
- Thu Aug 29 15:01:15 2013 +0000
- Revision:
- 3:1bb80997f316
- Parent:
- 2:42d461c96301
- Child:
- 4:d1d5a02cc721
I2C Slave working
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
Kit1 | 2:42d461c96301 | 1 | /*Program Example 7.6: I2C Slave, when called transfers switch state to mbed acting as Master, and |
Kit1 | 2:42d461c96301 | 2 | displays state of Master’ s switches on its leds. |
Kit1 | 2:42d461c96301 | 3 | */ |
Kit1 | 2:42d461c96301 | 4 | #include <mbed.h> |
Kit1 | 3:1bb80997f316 | 5 | I2CSlave slave(p28, p27); //Configure I2C slave |
Kit1 | 3:1bb80997f316 | 6 | DigitalOut red_led(LED1); //red led |
Kit1 | 3:1bb80997f316 | 7 | DigitalOut green_led(LED2); //green led |
Kit1 | 2:42d461c96301 | 8 | DigitalIn switch_ip1(p5); |
Kit1 | 2:42d461c96301 | 9 | DigitalIn switch_ip2(p6); |
Kit1 | 2:42d461c96301 | 10 | char switch_word ; //word we will send |
Kit1 | 2:42d461c96301 | 11 | char recd_val; //value received from master |
Kit1 | 2:42d461c96301 | 12 | |
Kit1 | 2:42d461c96301 | 13 | int main() { |
Kit1 | 2:42d461c96301 | 14 | slave.address(0x52); |
Kit1 | 2:42d461c96301 | 15 | while (1) { |
Kit1 | 2:42d461c96301 | 16 | //set up switch_word from switches that are pressed |
Kit1 | 2:42d461c96301 | 17 | switch_word=0xa0; //set up a recognizable output pattern |
Kit1 | 2:42d461c96301 | 18 | if (switch_ip1==1) |
Kit1 | 2:42d461c96301 | 19 | switch_word=switch_word|0x01; |
Kit1 | 2:42d461c96301 | 20 | if (switch_ip2==1) |
Kit1 | 2:42d461c96301 | 21 | switch_word=switch_word|0x02; |
Kit1 | 2:42d461c96301 | 22 | slave.write(switch_word); //load up word to send |
Kit1 | 2:42d461c96301 | 23 | //test for I2C, and act accordingly |
Kit1 | 2:42d461c96301 | 24 | int i = slave.receive(); |
Kit1 | 2:42d461c96301 | 25 | if (i == 3){ //slave is addressed, Master will write |
Kit1 | 2:42d461c96301 | 26 | recd_val= slave.read(); |
Kit1 | 2:42d461c96301 | 27 | //now set leds according to received word |
Kit1 | 2:42d461c96301 | 28 | red_led=0; //preset both to 0 |
Kit1 | 3:1bb80997f316 | 29 | green_led=0; |
Kit1 | 2:42d461c96301 | 30 | recd_val=recd_val&0x03; //AND out unwanted bits |
Kit1 | 2:42d461c96301 | 31 | if (recd_val==1) |
Kit1 | 2:42d461c96301 | 32 | red_led=1; |
Kit1 | 2:42d461c96301 | 33 | if (recd_val==2) |
Kit1 | 2:42d461c96301 | 34 | green_led=1; |
Kit1 | 2:42d461c96301 | 35 | if (recd_val==3){ |
Kit1 | 2:42d461c96301 | 36 | red_led=1; |
Kit1 | 2:42d461c96301 | 37 | green_led=1; |
Kit1 | 2:42d461c96301 | 38 | } |
Kit1 | 2:42d461c96301 | 39 | } |
Kit1 | 2:42d461c96301 | 40 | } |
Kit1 | 2:42d461c96301 | 41 | } |