Alisa Allaire / Mbed 2 deprecated 4180L1_P7

spi

Dependencies:   MCP23S17 mbed

Files at this revision

API Documentation at this revision

Revision 0:b08b1d99aaf3, committed 2018-01-18

Comitter:
aallaire3
Date:
Thu Jan 18 18:15:18 2018 +0000
Commit message:
spi

Changed in this revision

MCP23S17.lib Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP23S17.lib	Thu Jan 18 18:15:18 2018 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/romilly/code/MCP23S17/#068b1e8909bb

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Jan 18 18:15:18 2018 +0000
@@ -0,0 +1,59 @@
+// A simple IO demo using the MCP23S17 library
+//
+// MCP23S17 Library Copyright (c) 2010 Romilly Cocking
+// Released under the MIT License: http://mbed.org/license/mit
+//
+// See http://mbed.org/users/romilly/notebook/mcp23s17-addressable-16-bit-io-expander-with-spi/
+//
+//
+// 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
+// MCP23S17 reset pin pulled high
+// MCP23S17 GPA0 connected to GPB0 for loopback test
+// 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);
+
+
+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.
+//  But just leave it pulled high for this simple demo code.
+//  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;
+//
+//  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);
+
+//  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) {
+
+        // read back value from MCP23S17 Port B and display B0 on mbed led1
+        int led = !(chip.read(PORT_B) & 0x01);
+        chip.write(PORT_A, led);
+        // led1 should blink slowly when it is all working
+    }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Thu Jan 18 18:15:18 2018 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/7130f322cb7e
\ No newline at end of file