Revision 4:e63bb299bf30, committed 2022-09-09

Comitter:

mus3

Date:

Fri Sep 09 20:14:29 2022 +0000

Parent:

3:cb2f079f1f97

Commit message:

part7 now can use external led and pushbutton

Changed in this revision

diff -r cb2f079f1f97 -r e63bb299bf30 main.cpp
--- a/main.cpp	Thu Sep 08 16:10:29 2022 +0000
+++ b/main.cpp	Fri Sep 09 20:14:29 2022 +0000
@@ -8,11 +8,12 @@
 //
 // 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
@@ -21,12 +22,19 @@
 // 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
+DigitalOut reset(p14);
+
+DigitalOut red(p9);
+DigitalIn pblight(p8);
+
+// 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.
@@ -34,21 +42,30 @@
 //  After a power on reset, both IO ports default to input mode
 //
 //  Here is the optional code for a software reset
-//  reset = 0;
-//  wait_us(1);
-//  reset = 1;
+    reset = 0;
+    wait_us(1);
+    reset = 1;
+    
+    pblight.mode(PullUp);
+    wait(0.001);
 //
 //  Set all 8 Port A bits to output direction
     chip.direction(PORT_A, 0x00);
 //  Set all 8 Port B bits to input direction
     chip.direction(PORT_B, 0xFF);
-    led1=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) {
-        led1 = chip.read(PORT_B) & 0x01;
-        wait(0.1);
-        if (led1) chip.write(PORT_A, 0x55);
-        else chip.write(PORT_A, 0x00);
+        // write 0xAA to MCP23S17 Port A
+        chip.write(PORT_A, !pblight);
+        wait(.01);
+        // read back value from MCP23S17 Port B and display B0 on mbed led1
+        red = 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
     }
-}
\ No newline at end of file
+}