Revision 3:07745b21792d, committed 2015-02-18

Comitter:

lzzcd001

Date:

Wed Feb 18 14:49:26 2015 +0000

Parent:

2:934a0500abde

Commit message:

Extra problem 5 for HW 1

Changed in this revision

--- a/main.cpp	Fri Jan 28 02:04:05 2011 +0000
+++ b/main.cpp	Wed Feb 18 14:49:26 2015 +0000
@@ -13,6 +13,8 @@
 #include "MCP23S17.h"
 // Create SPI bus
 SPI spi(p5, p6, p7);
+DigitalOut a(p21);
+
 // 
 // Wiring Connections:
 // mbed p5,p6,p7 are tied to MCP23S17 SI, SO, SCK pins
@@ -22,10 +24,12 @@
 // A0, A1, A2 of the MCP23S17  are tied to ground on the breadboard, so the 8-bit address for writes is 0x40
 // This is referred to as the opcode in the device datasheet
 char Opcode = 0x40;
+char OpcodeIn = 0x42;
 
 // Next create a MCP23S17
 // mbed p20 is connected to ~chipSelect on the MCP23S17
 MCP23S17 chip = MCP23S17(spi, p20, Opcode);
+MCP23S17 chip2 = MCP23S17(spi, p20, OpcodeIn);
 
 // Optional software reset - mbed p14 to MCP23S17 reset pin
 // DigitalOut reset(p14);
@@ -33,6 +37,7 @@
 DigitalOut led1(LED1); // mbed LED1 is used for test status display
 
 int main() {
+    a = 1;
 //  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.
 //  But just leave it pulled high for this simple demo code.
@@ -47,20 +52,24 @@
     chip.direction(PORT_A, 0x00);
 //  Set all 8 Port B bits to input direction
     chip.direction(PORT_B, 0xFF);
+    chip2.direction(PORT_A, 0x00);
+    chip2.direction(PORT_B, 0xFF);
     led1=0;
+    int mid = 0;
 //  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) {
         // write 0xAA to MCP23S17 Port A
-        chip.write(PORT_A, 0xAA);
-        wait(.5);
+        mid = chip.read(PORT_B) & 0x01;
+        wait(.1);
+        chip.write(PORT_A, mid);
         // read back value from MCP23S17 Port B and display B0 on mbed led1
-        led1 = chip.read(PORT_B)& 0x01;
+        wait(.1);
+        mid = chip2.read(PORT_B);
+        wait(.1);
         // write 0x55 to MCP23S17 Port A
-        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;
+        chip2.write(PORT_A, mid);
+        wait(.1);
         // led1 should blink slowly when it is all working
     }
 }