Revision 3:bdc6c6bafe13, committed 2018-01-31

Comitter:

bjs9

Date:

Wed Jan 31 06:10:23 2018 +0000

Parent:

2:934a0500abde

Child:

4:58a089a8b601

Commit message:

changes to button

Changed in this revision

--- a/main.cpp	Fri Jan 28 02:04:05 2011 +0000
+++ b/main.cpp	Wed Jan 31 06:10:23 2018 +0000
@@ -31,7 +31,7 @@
 // DigitalOut reset(p14);
 
 DigitalOut led1(LED1); // mbed LED1 is used for test status display
-
+int B0;
 int main() {
 //  The MCP23S17 reset pin can just be pulled high, since it has a power on reset circuit.
 //  The reset pin can be used for a software forced reset by pulling it low with an mbed GPIO pin.
@@ -51,16 +51,23 @@
 //  Start Loopback test sending out and reading back values
 //  loopback test uses A0 and B0 pins - so use a wire to jumper those two pins on MCP23S17 together
     while (1) {
+        B0 = chip.read(PORT_B)& 0x01;
+        if (B0 == 0)
+        {
+            chip.write(PORT_A,1); // output 1 at A0 to light up LED 
+        } else {
+            chip.write(PORT_A,0); // turn off LED
+        }
         // write 0xAA to MCP23S17 Port A
-        chip.write(PORT_A, 0xAA);
-        wait(.5);
+       // chip.write(PORT_A, 0xAA);
+        //wait(.5);
         // read back value from MCP23S17 Port B and display B0 on mbed led1
-        led1 = chip.read(PORT_B)& 0x01;
+        //led1 = chip.read(PORT_B)& 0x01;
         // write 0x55 to MCP23S17 Port A
-        chip.write(PORT_A, 0x55);
-        wait(.5);
+        //chip.write(PORT_A, 0x55);
+        //wait(.5);
         // read back value from MCP23S17 Port B and display B0 on mbed led1
-        led1 = chip.read(PORT_B)& 0x01;
+        //led1 = chip.read(PORT_B)& 0x01;
         // led1 should blink slowly when it is all working
     }
 }