Diff: main.cpp

Revision:

0:2467aed99127

Child:

1:e180256ba6fb

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Aug 31 19:45:31 2011 +0000
@@ -0,0 +1,278 @@
+/* mbed bus - Main
+ * Copyright (c) 2011 Wim Huiskamp
+ *
+ * Released under the MIT License: http://mbed.org/license/mit
+ *
+ * version 0.2 Initial Release
+*/
+#include "mbed.h"
+#include "BusDefines.h"
+#include "PCF8574_DataBus.h"
+#include "PCF8574_AddressBus.h"
+#include "PCF8574_EnableBus.h"
+#include "MBED_ControlBus.h"
+  
+// Debug stuff
+#define __DEBUG  
+#include "Dbg.h"
+
+// mbed Interface Hardware definitions
+DigitalOut myled1(LED1);
+DigitalOut myled2(LED2);
+DigitalOut myled3(LED3);
+DigitalOut heartbeatLED(LED4);
+
+// Host PC Communication channels
+Serial pc(USBTX, USBRX);
+
+//I2C Bus
+I2C i2c(D_SDA, D_SCL);
+
+// Bus Interface Hardware definitions
+PCF8574_DataBus    databus = PCF8574_DataBus(i2c, D_I2C_DATA_BUS);  //Copy constructors..
+PCF8574_AddressBus addressbus = PCF8574_AddressBus(i2c, D_I2C_ADDR_BUS);
+PCF8574_EnableBus  enablebus = PCF8574_EnableBus(i2c, D_I2C_ENA_BUS);
+MBED_ControlBus  controlbus = MBED_ControlBus(D_WR, D_RD, D_DTR, D_CDBUF, D_CDINT);
+
+// Dummy delay
+#define DEVICE_WAIT_MS   0
+
+
+// Variables for Heartbeat and Status monitoring
+Ticker heartbeat;
+bool heartbeatflag=false;
+
+// Cycle Timer
+Timer cycletimer;
+int cyclecount = 0;
+const int maxcount = 10;
+
+// Local functions
+void clear_screen() {
+//ANSI Terminal Commands
+    pc.printf("\x1B[2J");
+    pc.printf("\x1B[H");
+}
+
+
+void init_interfaces() {
+// Init Host PC communication, default is 9600
+    pc.baud(D_BAUDRATE);
+      
+// Init I/F hardware
+    i2c.frequency(100000);  
+  
+    //Done, Tell me about it
+    myled1 = 1;
+    DBG("Init Interfaces Done\r");    
+}
+      
+
+// Heartbeat monitor
+void pulse() {
+  heartbeatLED = !heartbeatLED;
+}
+
+void heartbeat_start() {
+  heartbeat.attach(&pulse, 0.5);
+  heartbeatflag = true;
+}
+
+void heartbeat_stop() {
+  heartbeat.detach();
+  heartbeatflag = false;
+}
+
+void show_LEDS () {
+  static int state = 0;
+ 
+  switch (state) {
+   case 0: 
+        myled1 = 1;
+        myled2 = 0;
+        myled3 = 0;
+        state = 1;
+        break;
+   case 1: 
+        myled1 = 0;
+        myled2 = 1;
+        myled3 = 0;
+        state = 2;
+        break;
+   case 2:     
+        myled1 = 0;
+        myled2 = 0;
+        myled3 = 1;
+        state = 0;
+        break;
+   }
+}
+
+
+// The next two functions are examples of low-level reading and writing to a device that is connected on the mbed bus.
+// In your own application you can develop a Class for each specific slave device and include modified versions of the 
+// functions below as 'private' functions. This allows you to hardcode the device CS_pin signals, define specific delays
+// when needed, change the sequence of CS, WR etc or mask out certain address or databits when they are not used in a certain case.
+//
+
+/*---------------------------------------------------------------------------*\
+ |
+ |  Function:       write
+ |
+ |  Description:    Low level data write routine for device. Takes in data
+ |                  and address and CS pin to identify the device and writes
+ |                  data to the display. For simplicity, entire address byte
+ |                  is written, even though top two bits are unused inputs.
+ |                  After performing the operation, address lines are set
+ |                  all high, in order to eliminate current drain through
+ |                  pullup resistors (0.5mA per pin with 10K pullups)
+ |
+ |  Parameters:     address - full address in bits 0-5
+ |                  device  - enum CS_Pin for Chip Select pin
+ |                  data - data byte to write out
+ |
+ |  Returns:        Nothing.
+ |
+\*---------------------------------------------------------------------------*/
+
+void write(uint8_t address, CS_Pin device, uint8_t data)
+{
+//    // Switch databus buffer to outputs (note: this is the default state)
+//    controlbus.busdir(WRITE);        
+//    // Switch databus to outputs
+//    databus.busdir(WRITE);   
+
+    
+    // Write out the address on to the addressbus and wait
+    addressbus.write(address);
+    wait_ms(DEVICE_WAIT_MS);
+
+    // Set CE low and wait
+    enablebus.chipselect(device, LOW);  
+    wait_ms(DEVICE_WAIT_MS);
+
+    // Write data to the databus
+    databus.write(data);        
+    wait_ms(DEVICE_WAIT_MS);
+     
+    // Set WR low, wait, then set high and wait
+    controlbus.WR(LOW);
+    wait_ms(DEVICE_WAIT_MS);
+    controlbus.WR(HIGH);
+    wait_ms(DEVICE_WAIT_MS);
+
+    // Set CE high and wait
+    enablebus.chipselect(device, HIGH);  
+    wait_ms(DEVICE_WAIT_MS);
+    
+//    // Switch databus back to inputs
+//    databus.busdir(READ);        
+//    // Switch databus buffer back to inputs
+//    controlbus.busdir(READ);  
+
+//    // Set address lines all high to minimise power through pullups
+//    addressbus.write(0xFF);
+}
+
+/*---------------------------------------------------------------------------*\
+ |
+ |  Function:       read
+ |
+ |  Description:    Low level data read routine for a Device. Takes in 
+ |                  address and CS pin to identify the device and then 
+ |                  reads data from the device.
+ |                  After performing the operation, address lines are set
+ |                  all high, in order to eliminate current drain through
+ |                  pullup resistors (0.5mA per pin with 10K pullups)
+ |
+ |  Parameters:     address - 8 bit address
+ |                  device  - enum CS_Pin for Chip Select pin
+ |  Returns:        data - data byte read
+ |
+\*---------------------------------------------------------------------------*/
+
+uint8_t read(uint8_t address, CS_Pin device)
+{
+    uint8_t data = 0;
+
+    // Switch databus to inputs (default state is output)
+    databus.busdir(READ);        
+    // Switch databus buffer to inputs
+    controlbus.busdir(READ);      
+       
+    // Write out the address on to the addressbus and wait
+    addressbus.write(address);
+    wait_ms(DEVICE_WAIT_MS);
+
+    // Set CE low and wait
+    enablebus.chipselect(device, LOW);
+    wait_ms(DEVICE_WAIT_MS);
+
+    // Set RD low and wait
+    controlbus.RD(LOW);
+    wait_ms(DEVICE_WAIT_MS);
+    
+    // Read the data byte from databus
+    data = databus.read();
+
+    // set RD high and wait
+    controlbus.RD(HIGH);
+    wait_ms(DEVICE_WAIT_MS);
+
+    // Set CE high and wait
+    enablebus.chipselect(device, HIGH);
+    wait_ms(DEVICE_WAIT_MS);
+
+//    // Set address lines all high to minimise power through pullups
+//    addressbus.write(0xFF);
+
+    // Switch databus buffer back to outputs
+    controlbus.busdir(WRITE);        
+    // Switch databus to outputs
+    databus.busdir(WRITE);   
+    
+    // Return read data to caller
+    return data;
+}
+
+int main() {
+    int address, result;
+    uint8_t data, dummy;
+
+    init_interfaces();
+    
+    heartbeat_start();
+          
+    clear_screen(); 
+        
+    DBG("Start Main Loop\r");    
+
+//Testing stuff
+        
+    //Test cycletime
+    cycletimer.start();      
+    cycletimer.reset();
+    
+    while (1) {
+      for (address=0; address<256; address++) {
+        //data = read(address, CS_SWITCH);
+        
+        dummy = ~address;
+        write(address, LATCHEN_1, dummy); 
+//        wait(0.05);       
+      }    
+    
+      // Just for Info, lets see how fast this cycle is...
+      cyclecount++;
+      if (cyclecount == maxcount) {
+        pc.printf("Freq = %d Hz\r", (cyclecount * 256 * 1000) / cycletimer.read_ms());
+        cyclecount = 0;          
+        cycletimer.reset();      
+      }
+      
+      show_LEDS ();      
+    }
+
+      
+    DBG("I'll be back...\r\r");
+}