beginning coursework

Coursework/Makefile

@@ -0,0 +1,7 @@
+CONTIKI_PROJECT = coursework
+all: $(CONTIKI_PROJECT)
+
+#UIP_CONF_IPV6=1
+
+CONTIKI = ../..
+include $(CONTIKI)/Makefile.include

Coursework/buffer.h

@@ -0,0 +1,60 @@
+#ifndef _BUFFER_GUARD
+#define _BUFFER_GUARD
+
+#include "util.h"
+
+void 
+aggregateBuffer(float bufferIn[], int lengthIn, float bufferOut[], int lengthOut, int groupSize)
+{
+    int requiredGroups = ceil((float)lengthIn/groupSize);
+    int finalGroupSize = (lengthIn % groupSize) * groupSize;
+
+    if(requiredGroups > lengthOut)
+    {
+        putFloat((float)lengthIn/groupSize);
+        printf(" length out buffer required, %i provided", lengthOut);
+        return;
+    }
+
+    int g;// for group number
+    for(g = 0; g < requiredGroups; g++)
+    {
+        int length = groupSize;
+        if(g == requiredGroups - 1 && finalGroupSize != 0) length = finalGroupSize;
+        bufferOut[g] = calculateMean(&bufferIn + (g*groupSize), length);
+    }
+}
+
+void 
+clearBuffer(float buffer[], int length)
+{
+    if(length > 0)
+    {
+        int i;
+        for(i = 0; i < length; i++)
+        {
+            buffer[i] = 0.0;
+        }
+    }
+}
+
+void 
+printBuffer(float buffer[], int length)
+{
+    putchar('[');
+
+    if(length > 0)
+    {
+        int i;
+        for(i = 0; i < length; i++)
+        {
+            if(i > 0) printf(", ");
+
+            putFloat(buffer[i]);
+        }
+    }    
+
+    putchar(']');
+}
+
+#endif

Coursework/cooja_coursework.csc

@@ -0,0 +1,137 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<simconf>
+  <project EXPORT="discard">[CONTIKI_DIR]/tools/cooja/apps/mrm</project>
+  <project EXPORT="discard">[CONTIKI_DIR]/tools/cooja/apps/mspsim</project>
+  <project EXPORT="discard">[CONTIKI_DIR]/tools/cooja/apps/avrora</project>
+  <project EXPORT="discard">[CONTIKI_DIR]/tools/cooja/apps/serial_socket</project>
+  <project EXPORT="discard">[CONTIKI_DIR]/tools/cooja/apps/collect-view</project>
+  <project EXPORT="discard">[CONTIKI_DIR]/tools/cooja/apps/powertracker</project>
+  <simulation>
+    <title>Aggregator Coursework</title>
+    <speedlimit>1.0</speedlimit>
+    <randomseed>123456</randomseed>
+    <motedelay_us>1000000</motedelay_us>
+    <radiomedium>
+      se.sics.cooja.radiomediums.UDGM
+      <transmitting_range>50.0</transmitting_range>
+      <interference_range>100.0</interference_range>
+      <success_ratio_tx>1.0</success_ratio_tx>
+      <success_ratio_rx>1.0</success_ratio_rx>
+    </radiomedium>
+    <events>
+      <logoutput>40000</logoutput>
+    </events>
+    <motetype>
+      se.sics.cooja.mspmote.SkyMoteType
+      <identifier>sky1</identifier>
+      <description>Sky Mote Type #sky1</description>
+      <source EXPORT="discard">[CONTIKI_DIR]/surrey/Coursework/coursework.c</source>
+      <commands EXPORT="discard">make coursework.sky TARGET=sky</commands>
+      <firmware EXPORT="copy">[CONTIKI_DIR]/surrey/Coursework/coursework.sky</firmware>
+      <moteinterface>se.sics.cooja.interfaces.Position</moteinterface>
+      <moteinterface>se.sics.cooja.interfaces.RimeAddress</moteinterface>
+      <moteinterface>se.sics.cooja.interfaces.IPAddress</moteinterface>
+      <moteinterface>se.sics.cooja.interfaces.Mote2MoteRelations</moteinterface>
+      <moteinterface>se.sics.cooja.interfaces.MoteAttributes</moteinterface>
+      <moteinterface>se.sics.cooja.mspmote.interfaces.MspClock</moteinterface>
+      <moteinterface>se.sics.cooja.mspmote.interfaces.MspMoteID</moteinterface>
+      <moteinterface>se.sics.cooja.mspmote.interfaces.SkyButton</moteinterface>
+      <moteinterface>se.sics.cooja.mspmote.interfaces.SkyFlash</moteinterface>
+      <moteinterface>se.sics.cooja.mspmote.interfaces.SkyCoffeeFilesystem</moteinterface>
+      <moteinterface>se.sics.cooja.mspmote.interfaces.Msp802154Radio</moteinterface>
+      <moteinterface>se.sics.cooja.mspmote.interfaces.MspSerial</moteinterface>
+      <moteinterface>se.sics.cooja.mspmote.interfaces.SkyLED</moteinterface>
+      <moteinterface>se.sics.cooja.mspmote.interfaces.MspDebugOutput</moteinterface>
+      <moteinterface>se.sics.cooja.mspmote.interfaces.SkyTemperature</moteinterface>
+    </motetype>
+    <mote>
+      <breakpoints />
+      <interface_config>
+        se.sics.cooja.interfaces.Position
+        <x>29.99841204907099</x>
+        <y>-115.95137024353158</y>
+        <z>0.0</z>
+      </interface_config>
+      <interface_config>
+        se.sics.cooja.mspmote.interfaces.MspMoteID
+        <id>1</id>
+      </interface_config>
+      <motetype_identifier>sky1</motetype_identifier>
+    </mote>
+  </simulation>
+  <plugin>
+    se.sics.cooja.plugins.SimControl
+    <width>417</width>
+    <z>0</z>
+    <height>160</height>
+    <location_x>400</location_x>
+    <location_y>0</location_y>
+  </plugin>
+  <plugin>
+    se.sics.cooja.plugins.Visualizer
+    <plugin_config>
+      <skin>se.sics.cooja.plugins.skins.IDVisualizerSkin</skin>
+      <viewport>0.9090909090909091 0.0 0.0 0.9090909090909091 153.72871631902638 172.41033658502872</viewport>
+    </plugin_config>
+    <width>393</width>
+    <z>4</z>
+    <height>430</height>
+    <location_x>1</location_x>
+    <location_y>1</location_y>
+  </plugin>
+  <plugin>
+    se.sics.cooja.plugins.TimeLine
+    <plugin_config>
+      <mote>0</mote>
+      <showRadioRXTX />
+      <showRadioHW />
+      <showLEDs />
+      <split>-1</split>
+      <zoomfactor>500.0</zoomfactor>
+    </plugin_config>
+    <width>397</width>
+    <z>3</z>
+    <height>443</height>
+    <location_x>0</location_x>
+    <location_y>433</location_y>
+  </plugin>
+  <plugin>
+    se.sics.cooja.plugins.Notes
+    <plugin_config>
+      <notes>Enter notes here</notes>
+      <decorations>true</decorations>
+    </plugin_config>
+    <width>6</width>
+    <z>5</z>
+    <height>160</height>
+    <location_x>680</location_x>
+    <location_y>0</location_y>
+  </plugin>
+  <plugin>
+    se.sics.cooja.plugins.MoteInterfaceViewer
+    <mote_arg>0</mote_arg>
+    <plugin_config>
+      <interface>Serial port</interface>
+      <scrollpos>0,0</scrollpos>
+    </plugin_config>
+    <width>1201</width>
+    <z>1</z>
+    <height>706</height>
+    <location_x>397</location_x>
+    <location_y>162</location_y>
+  </plugin>
+  <plugin>
+    se.sics.cooja.plugins.MoteInterfaceViewer
+    <mote_arg>0</mote_arg>
+    <plugin_config>
+      <interface>Temperature and Light</interface>
+      <scrollpos>0,0</scrollpos>
+    </plugin_config>
+    <width>397</width>
+    <z>2</z>
+    <height>179</height>
+    <location_x>2</location_x>
+    <location_y>247</location_y>
+  </plugin>
+</simconf>
+

Coursework/coursework.c

@@ -0,0 +1,107 @@
+#define READING_INTERVAL 3 //in Hz
+#define BUFFER_SIZE 5
+
+#define SD_THRESHOLD 3
+#define AGGREGATION_GROUP_SIZE 4
+
+#include "contiki.h"
+#include "dev/light-sensor.h"
+
+#include <stdio.h> /* For printf() */
+
+#include "util.h" // for print methods
+#include "math.h"
+#include "buffer.h"
+
+// get float from light sensor including T function
+float
+getLight(void)
+{
+    int lightData = light_sensor.value(LIGHT_SENSOR_PHOTOSYNTHETIC);
+
+    float V_sensor = 1.5 * lightData / 4096;
+    float I = V_sensor/1e5;
+    float light = 0.625 * 1e6 * I * 1000;
+    return light;
+}
+
+// Process final buffer following aggregation
+void
+handleFinalBuffer(float buffer[], int length)
+{
+    printf("Final buffer output: ");
+    printBuffer(buffer, length);putchar('\n');putchar('\n');
+}
+
+// Buffer filled with readings, process and aggregate
+void
+handleBufferRotation(float buffer[], int length)
+{
+    printf("Buffer full, aggregating\n\n");
+    float aggregated[BUFFER_SIZE];
+
+    Stats sd = calculateStdDev(buffer, length);
+    if(sd.std > SD_THRESHOLD)
+    {// buffer length by 4
+        printf("Significant STD: ");
+        putFloat(sd.std);
+        printf(", compressing buffer\n");
+
+        float outBuffer[BUFFER_SIZE];
+        int outLength = ceil((float)length/AGGREGATION_GROUP_SIZE);
+        aggregateBuffer(buffer, length, outBuffer, outLength, AGGREGATION_GROUP_SIZE);
+
+        handleFinalBuffer(outBuffer, outLength);
+    }else
+    {// buffer length to 1
+        printf("Insignificant STD: ");
+        putFloat(sd.std);
+        printf(", squashing buffer\n");
+
+        handleFinalBuffer(&sd.mean, 1);
+    }
+    clearBuffer(buffer, length);
+}
+
+float buffer[BUFFER_SIZE];
+
+/*---------------------------------------------------------------------------*/
+PROCESS(aggregator_process, "Aggregator process");
+AUTOSTART_PROCESSES(&aggregator_process);
+/*---------------------------------------------------------------------------*/
+PROCESS_THREAD(aggregator_process, ev, data)
+{
+    /*INIT*/
+    static struct etimer timer;
+    PROCESS_BEGIN();
+
+    etimer_set(&timer, CLOCK_SECOND/READING_INTERVAL);
+    SENSORS_ACTIVATE(light_sensor);
+    
+    clearBuffer(buffer, BUFFER_SIZE);
+    printBuffer(buffer, BUFFER_SIZE);putchar('\n');putchar('\n');
+    /*END INIT*/
+    
+    static int counter = 0;
+    while(1)
+    {
+        PROCESS_WAIT_EVENT_UNTIL(ev=PROCESS_EVENT_TIMER);
+        
+        float light_lx = getLight();
+
+        buffer[counter] = light_lx;
+        printBuffer(buffer, BUFFER_SIZE);putchar('\n');
+        
+        counter++;
+        if(counter == BUFFER_SIZE)
+        {
+            handleBufferRotation(buffer, BUFFER_SIZE);
+            counter = 0;
+        }
+
+        etimer_reset(&timer);
+    }
+
+    PROCESS_END();
+}
+/*---------------------------------------------------------------------------*/

Coursework/math.h

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+#ifndef _MATH_GUARD
+#define _MATH_GUARD
+
+typedef struct Stats {
+    float mean;
+    float std;
+} Stats;
+
+int
+ceil(float in)
+{
+    int num = (int) in;
+    if(in - num > 0) num++;
+    return num;
+}
+
+float
+sqrt(float in)
+{
+    float sqrt = in/2;
+    float temp = 0;
+
+    while(sqrt != temp)
+    {
+        temp = sqrt;
+        sqrt = (in/temp + temp) / 2;
+    }
+    return sqrt;
+}
+
+float
+calculateMean(float buffer[], int length)
+{
+    if(length <= 0)
+    {
+        printf("%i items is not valid length\n", length);
+        return 0;
+    }
+
+    float sum = 0;
+    int i;
+    for(i = 0; i < length; i++)
+    {
+        sum += buffer[i];
+    }
+    
+    return sum / length;
+}
+
+Stats
+calculateStdDev(float buffer[], int length)
+{
+    Stats stats;
+    if(length <= 0)
+    {
+        printf("%i items is not valid length\n", length);
+        return stats;
+    }
+
+    stats.mean = calculateMean(buffer, length);
+
+    float sum = 0;
+    int i;
+    for(i = 0; i < length; i++)
+    {
+        float diffFromMean = buffer[i] - stats.mean;
+        sum += diffFromMean*diffFromMean;
+    }
+    
+    stats.std = sqrt(sum/length);
+
+    return stats;
+}
+
+#endif

Coursework/symbols.c

@@ -0,0 +1,4 @@
+#include "symbols.h"
+
+const int symbols_nelts = 0;
+const struct symbols symbols[] = {{0,0}};

Coursework/symbols.h

@@ -0,0 +1,3 @@
+#include "loader/symbols.h"
+
+extern const struct symbols symbols[1];

Coursework/util.h

@@ -0,0 +1,37 @@
+#ifndef _UTIL_GUARD
+#define _UTIL_GUARD
+
+typedef unsigned short USHORT;
+
+//print a unsigned short (as returned from rand) picewise char by char
+void
+putShort(USHORT in) 
+{
+    // recursively shift each digit of the int to units from most to least significant
+    if (in >= 10)
+    {
+        putShort(in / 10);
+    }
+    // isolate unit digit from each number by modulo and add '0' char to turn integer into corresponding ascii char
+    putchar((in % 10) + '0');
+}
+
+void
+putFloat(float in)
+{
+    if(in < 0) 
+    {
+        putchar('-'); // print negative sign if required
+        in = -in;
+    }	
+	
+    USHORT integerComponent = (USHORT) in; // truncate float to integer
+    float fractionComponent =  (in - integerComponent) * 1000; // take fraction only and promote to integer
+    if (fractionComponent - (USHORT)fractionComponent >= 0.5) fractionComponent++; // round
+
+    putShort(integerComponent);
+    putchar('.');
+    putShort((USHORT) fractionComponent);
+}
+
+#endif