Diff: main.cpp

Revision:

0:09c1e7c28d04

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Mar 07 11:36:12 2017 +0000
@@ -0,0 +1,46 @@
+ /*Program Example 7.6: I2C Slave, when called transfers switch state to mbed acting as
+Master, and displays state of Master’s switches on its leds.
+*/
+#include <mbed.h>
+I2CSlave slave(p9, p10); //Configure I2C slave
+DigitalOut red_led(p25); //red led
+DigitalOut green_led(p26); //green led
+DigitalIn switch_ip1(p5);
+DigitalIn switch_ip2(p6);
+
+char switch_word ; //word we will send
+char recd_val; //value received from master
+
+int main() 
+{
+    slave.address(0x52);
+    while (1) {
+        //set up switch_word from switches that are pressed
+        switch_word=0xa0; //set up a recognizable output pattern
+        if (switch_ip1==1)
+            switch_word=switch_word | 0x01;
+        if (switch_ip2==1)
+            switch_word=switch_word | 0x02;
+        slave.write(switch_word); //load up word to send
+        //test for I2C, and act accordingly
+        int i = slave.receive();
+        if (i == 3)
+            { 
+            //slave is addressed, Master will write
+            recd_val= slave.read();
+            //now set leds according to received word
+            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;
+                }
+            }
+        }
+}
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