Revision 3:cb2f079f1f97, committed 22 months ago

Comitter:

logostarr

Date:

Thu Sep 08 16:10:29 2022 +0000

Parent:

2:934a0500abde

Child:

4:e63bb299bf30

Commit message:

PArt 7

Changed in this revision

--- a/main.cpp	Fri Jan 28 02:04:05 2011 +0000
+++ b/main.cpp	Thu Sep 08 16:10:29 2022 +0000
@@ -8,12 +8,11 @@
 //
 // MCP23S17 datasheet http://ww1.microchip.com/downloads/en/DeviceDoc/21952b.pdf
 // uses MCP23S17 library version 0.4
-
 #include "mbed.h"
 #include "MCP23S17.h"
 // Create SPI bus
 SPI spi(p5, p6, p7);
-// 
+//
 // Wiring Connections:
 // mbed p5,p6,p7 are tied to MCP23S17 SI, SO, SCK pins
 // mbed p20 to MCP23S17 CS
@@ -22,16 +21,12 @@
 // 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;
-
 // Next create a MCP23S17
 // mbed p20 is connected to ~chipSelect on the MCP23S17
 MCP23S17 chip = MCP23S17(spi, p20, Opcode);
-
 // Optional software reset - mbed p14 to MCP23S17 reset pin
 // DigitalOut reset(p14);
-
 DigitalOut led1(LED1); // mbed LED1 is used for test status display
-
 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 +46,9 @@
 //  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);
-        // read back value from MCP23S17 Port B and display B0 on mbed led1
-        led1 = chip.read(PORT_B)& 0x01;
-        // 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;
-        // led1 should blink slowly when it is all working
+        led1 = chip.read(PORT_B) & 0x01;
+        wait(0.1);
+        if (led1) chip.write(PORT_A, 0x55);
+        else chip.write(PORT_A, 0x00);
     }
-}
+}
\ No newline at end of file