BAT-SD4012_2017 / Mbed 2 deprecated ECE4180Lab1_3

I do it

Dependencies:   MCP23S17 mbed

main.cpp@0:34f3e96385fa, 2017-10-05 (annotated)

Committer:
goodguy8791
Date:
Thu Oct 05 18:52:46 2017 +0000
Revision:
0:34f3e96385fa
I do it

Who changed what in which revision?

UserRevisionLine numberNew contents of line
goodguy8791 0:34f3e96385fa 1 //NEED TO ADD “MCP23S17.cpp” AND “MCP23S17.h” TO PROJECT FILE
goodguy8791 0:34f3e96385fa 2
goodguy8791 0:34f3e96385fa 3 // A simple IO demo using the MCP23S17 library
goodguy8791 0:34f3e96385fa 4 //
goodguy8791 0:34f3e96385fa 5 // MCP23S17 Library Copyright (c) 2010 Romilly Cocking
goodguy8791 0:34f3e96385fa 6 // Released under the MIT License: http://mbed.org/license/mit
goodguy8791 0:34f3e96385fa 7 //
goodguy8791 0:34f3e96385fa 8 // See http://mbed.org/users/romilly/notebook/mcp23s17-addressable-16-bit-io-expander-with-spi/
goodguy8791 0:34f3e96385fa 9 //
goodguy8791 0:34f3e96385fa 10 //
goodguy8791 0:34f3e96385fa 11 // MCP23S17 datasheet http://ww1.microchip.com/downloads/en/DeviceDoc/21952b.pdf
goodguy8791 0:34f3e96385fa 12 // uses MCP23S17 library version 0.4
goodguy8791 0:34f3e96385fa 13
goodguy8791 0:34f3e96385fa 14 #include "mbed.h"
goodguy8791 0:34f3e96385fa 15 #include "MCP23S17.h"
goodguy8791 0:34f3e96385fa 16 // Create SPI bus
goodguy8791 0:34f3e96385fa 17 SPI spi(p5, p6, p7);
goodguy8791 0:34f3e96385fa 18 //
goodguy8791 0:34f3e96385fa 19 // Wiring Connections:
goodguy8791 0:34f3e96385fa 20 // mbed p5,p6,p7 are tied to MCP23S17 SI, SO, SCK pins
goodguy8791 0:34f3e96385fa 21 // mbed p20 to MCP23S17 CS
goodguy8791 0:34f3e96385fa 22 // MCP23S17 reset pin pulled high
goodguy8791 0:34f3e96385fa 23 // MCP23S17 GPA0 connected to GPB0 for loopback test
goodguy8791 0:34f3e96385fa 24 // A0, A1, A2 of the MCP23S17 are tied to ground on the breadboard, so the 8-bit address for writes is 0x40
goodguy8791 0:34f3e96385fa 25 // This is referred to as the opcode in the device datasheet
goodguy8791 0:34f3e96385fa 26 char Opcode = 0x40;
goodguy8791 0:34f3e96385fa 27
goodguy8791 0:34f3e96385fa 28 // Next create a MCP23S17
goodguy8791 0:34f3e96385fa 29 // mbed p20 is connected to ~chipSelect on the MCP23S17
goodguy8791 0:34f3e96385fa 30 MCP23S17 chip = MCP23S17(spi, p20, Opcode);
goodguy8791 0:34f3e96385fa 31
goodguy8791 0:34f3e96385fa 32 // Optional software reset - mbed p14 to MCP23S17 reset pin
goodguy8791 0:34f3e96385fa 33 // DigitalOut reset(p14);
goodguy8791 0:34f3e96385fa 34
goodguy8791 0:34f3e96385fa 35 DigitalOut led1(LED1); // mbed LED1 is used for test status display
goodguy8791 0:34f3e96385fa 36 //DigitalIn pb(p21);
goodguy8791 0:34f3e96385fa 37 int pb;
goodguy8791 0:34f3e96385fa 38
goodguy8791 0:34f3e96385fa 39 int main() {
goodguy8791 0:34f3e96385fa 40 // The MCP23S17 reset pin can just be pulled high, since it has a power on reset circuit.
goodguy8791 0:34f3e96385fa 41 // The reset pin can be used for a software forced reset by pulling it low with an mbed GPIO pin.
goodguy8791 0:34f3e96385fa 42 // But just leave it pulled high for this simple demo code.
goodguy8791 0:34f3e96385fa 43 // After a power on reset, both IO ports default to input mode
goodguy8791 0:34f3e96385fa 44 //
goodguy8791 0:34f3e96385fa 45 // Here is the optional code for a software reset
goodguy8791 0:34f3e96385fa 46 // reset = 0;
goodguy8791 0:34f3e96385fa 47 // wait_us(1);
goodguy8791 0:34f3e96385fa 48 // reset = 1;
goodguy8791 0:34f3e96385fa 49 //
goodguy8791 0:34f3e96385fa 50 // Set all 8 Port A bits to output direction
goodguy8791 0:34f3e96385fa 51 chip.direction(PORT_A, 0x00);
goodguy8791 0:34f3e96385fa 52
goodguy8791 0:34f3e96385fa 53 // Set all 8 Port B bits to input direction
goodguy8791 0:34f3e96385fa 54 chip.direction(PORT_B, 0xFF);
goodguy8791 0:34f3e96385fa 55 //led1=0;
goodguy8791 0:34f3e96385fa 56 // Start Loopback test sending out and reading back values
goodguy8791 0:34f3e96385fa 57 // loopback test uses A0 and B0 pins - so use a wire to jumper those two pins on MCP23S17 together
goodguy8791 0:34f3e96385fa 58
goodguy8791 0:34f3e96385fa 59 while (1) {
goodguy8791 0:34f3e96385fa 60 /*
goodguy8791 0:34f3e96385fa 61 // write 0xAA to MCP23S17 Port A
goodguy8791 0:34f3e96385fa 62 chip.write(PORT_A, 0xAA);
goodguy8791 0:34f3e96385fa 63 wait(.5);
goodguy8791 0:34f3e96385fa 64 // read back value from MCP23S17 Port B and display B0 on mbed led1
goodguy8791 0:34f3e96385fa 65 led1 = chip.read(PORT_B)& 0x01;
goodguy8791 0:34f3e96385fa 66 // write 0x55 to MCP23S17 Port A
goodguy8791 0:34f3e96385fa 67 chip.write(PORT_A, 0x55);
goodguy8791 0:34f3e96385fa 68 wait(.5);
goodguy8791 0:34f3e96385fa 69 // read back value from MCP23S17 Port B and display B0 on mbed led1
goodguy8791 0:34f3e96385fa 70 led1 = chip.read(PORT_B)& 0x01;
goodguy8791 0:34f3e96385fa 71 // led1 should blink slowly when it is all working
goodguy8791 0:34f3e96385fa 72 */
goodguy8791 0:34f3e96385fa 73
goodguy8791 0:34f3e96385fa 74 pb = chip.read(PORT_B) & 0x01;
goodguy8791 0:34f3e96385fa 75 if(pb == 0){
goodguy8791 0:34f3e96385fa 76 chip.write(PORT_A, 1);
goodguy8791 0:34f3e96385fa 77 }else{
goodguy8791 0:34f3e96385fa 78 chip.write(PORT_A, 0);
goodguy8791 0:34f3e96385fa 79 }
goodguy8791 0:34f3e96385fa 80
goodguy8791 0:34f3e96385fa 81 }
goodguy8791 0:34f3e96385fa 82 }
goodguy8791 0:34f3e96385fa 83