phil dani
/
I2CSlave
I2C Slave Example
Fork of HelloWorld by
Diff: Mmain.cpp
- Revision:
- 3:1bb80997f316
- Parent:
- 2:42d461c96301
diff -r 42d461c96301 -r 1bb80997f316 Mmain.cpp --- a/Mmain.cpp Thu Aug 29 12:35:44 2013 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,45 +0,0 @@ -/*Program Example 7.5: I2C Master, transfers switch state to second mbed acting as slave, and -displays state of slave’ s switches on its leds. -*/ -#include "mbed.h" -I2C i2c_port(p9, p10); //Configure a serial port, pins 9 and 10 are sda, scl -DigitalOut red_led(LED1); //red led -DigitalOut green_led(LED2); //green led -DigitalIn switch_ip1(p5); //input switch -DigitalIn switch_ip2(p6); -char switch_word ; //word we will send -char recd_val; //value received from slave -const int addr = 0x52; //the I2C slave address, an arbitrary even number - -int main() { - while(1) { - switch_word=0xa0; //set up a recognizable output pattern - if (switch_ip1==1) - switch_word=switch_word|0x01; //OR in lsb - if (switch_ip2==1) - switch_word=switch_word|0x02; //OR in next lsb - //send a single byte of data, in correct I2C package - i2c_port.start(); //force a start condition - i2c_port.write(addr); //send the address - i2c_port.write(switch_word); //send one byte of data, ie switch_word - i2c_port.stop(); //force a stop condition - wait(0.002); - //receive a single byte of data, in correct I2C package - i2c_port.start(); - i2c_port.write(addr|0x01); //send address, with R/W bit set to Read - recd_val=i2c_port.read(addr); //Read and save the received byte - i2c_port.stop(); //force a stop condition - //set leds according to word received from slave - red_led=0; //preset both to 0 - green_led=0; - recd_val=recd_val&0x03; //AND out unwanted bits - if (recd_val==1) - red_led=1; - if (recd_val==2) - green_led=1; - if (recd_val==3){ - red_led=1; - green_led=1; - } - } -}