Diff: sensorinterface.cpp

Revision:

0:bb17d0395fb8

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sensorinterface.cpp	Mon May 18 16:16:15 2015 +0000
@@ -0,0 +1,210 @@
+#include "sensorinterface.h"
+ 
+sensorinterface::sensorinterface() : i2c(p28,p27), readyLine(p29)
+{ 
+    readyLine.fall(this, &sensorinterface::readySet);
+    readyLine.rise(this, &sensorinterface::readyUnset);
+    
+    this->ready = false;
+    
+    char buffer[255];
+    
+    #ifdef DEBUG
+        printf("[SIF] Scanning for devices...\r\n");
+    #endif
+    
+    for (char i=1; i<=254; i=i+2)
+    {
+        //last bit determines read/write not actual address
+        if (this->i2c.read(i, &buffer[0], 1) ==0)
+        {
+            //returns 0 if ack i.e. a device is found
+            sensor newSensor;
+            newSensor = findType(newSensor, i);
+            this->sensors[i] = newSensor;
+            #ifdef DEBUG
+                printf("[SIF] Device found at 0x%.2X, device count: %i\r\n", i, this->sensors.size());
+            #endif
+        }
+    }
+}
+
+bool sensorinterface::isDataWaiting()
+{
+    return this->ready;
+}
+
+void sensorinterface::requestData()
+{
+    if (sensors.size() > 0)
+    {
+        currentSensor = sensors.begin();
+        
+        #ifdef DEBUG
+            printf("[SIF] Beginning device query chain from 0x%.2X\r\n", currentSensor->first);
+        #endif
+        
+        sendRequest(currentSensor->first);
+    }
+    else
+    {
+        #ifdef DEBUG
+            printf("[SIF] Data requested, but no devices present\r\n");
+        #endif
+    }
+}
+
+void sensorinterface::readySet()
+{
+    this->ready = true;
+}
+
+void sensorinterface::readyUnset()
+{
+    this->ready = false;
+}
+
+#ifdef DEBUG
+void sensorinterface::error(int e_num)
+{
+    printf("[SIF] Error %i\r",e_num);
+}
+#endif
+ 
+int sensorinterface::update()
+{
+    char buffer[255];
+    
+    for (char i=1; i<=254; i=i+2)
+    {
+        //last bit determines read/write not actual address
+        
+        bool connected = (this->i2c.read(i, &buffer[0], 1) == 0);
+        bool registered = (this->sensors.count(i) > 0);
+        
+        if (connected)
+        {
+            if (!registered)
+            {
+                //device added
+                #ifdef DEBUG
+                    printf("[SIF] Device added at %i\r\n", i);
+                #endif
+                sensor newSensor;
+                newSensor = findType(newSensor, i);
+                this->sensors[i] = newSensor;
+            }
+        }
+        else if (registered)
+        {
+            if (!connected)
+            {
+                //device removed
+                #ifdef DEBUG
+                    printf("[SIF] Device removed at %i\r\n", i);
+                #endif
+                this->sensors.erase(i);
+            }
+        }
+    }
+    
+    return 1;
+}
+ 
+ 
+sensor& sensorinterface::findType(sensor& s, int address)
+{
+    char response[I2C_TYPE_PACKET_SIZE];
+    char cmd[1] = {I2C_TYPE_HEADER};
+ 
+    this->i2c.write(address, cmd, 1);
+    int type_timeout = 10;
+    i2c.stop();
+    i2c.start();
+    while( (this->i2c.read(address, response, I2C_TYPE_PACKET_SIZE)) && (type_timeout) )
+    {
+        --type_timeout;
+        if (type_timeout == 2)
+        {
+            #ifdef DEBUG
+                error(3);
+            #endif
+            return s;
+        }
+    }
+
+    if (response[0] != I2C_TYPE_HEADER)
+    {
+        #ifdef DEBUG
+            error(1);
+        #endif
+    }
+
+    s.type = response[1];
+    s.packetSize = response[2];
+    s.readingSize = response[3]; 
+    return s;
+}
+ 
+int sensorinterface::sendRequest(char address)
+{
+    char cmd[1] = {I2C_REQUEST_HEADER};
+ 
+    this->i2c.write(address, cmd, 1);
+    
+    return 1;
+}
+ 
+d_reply sensorinterface::readData()
+{
+    #ifdef DEBUG
+        printf("[SIF] Reading data from current device (0x%.2X)\r\n", currentSensor->first);
+    #endif
+    char address = currentSensor->first;
+    char cmd[1] = {I2C_DATA_HEADER};
+    char bufSize = currentSensor->second.packetSize + 2;
+    char buffer[bufSize];
+    this->i2c.write(address, cmd, 1);
+    wait(0.01);
+    this->i2c.read(address, buffer, bufSize);
+    
+    d_reply reply;
+    
+    reply.type = currentSensor->second.type;
+    
+    for (int i = 2; i < bufSize; i += currentSensor->second.readingSize)
+    {
+        int r = 0;
+        for (int j = 0; j < currentSensor->second.readingSize; j++)
+        {
+            r = r << 8;
+            r += buffer[i+j];
+        }
+        reply.readings.push_back(r);
+    }
+ 
+    if (buffer[0] != I2C_DATA_HEADER)
+    {
+        //if it doesn't send the correct header bit, something has gone wrong
+        #ifdef DEBUG
+            error(0);
+        #endif
+    }
+    
+    if (currentSensor != sensors.end() && sensors.size() > 1 )
+    {
+        #ifdef DEBUG
+            printf("[SIF] Continuing chain of devices, just read from device: 0x%.2X\r\n", currentSensor->first);
+        #endif
+        currentSensor++;
+        sendRequest(currentSensor->first);
+    }
+    #ifdef DEBUG
+    else
+    {
+        printf("[SIF] All devices have been read from, end of chain\r\n");
+    }
+    #endif
+    
+    return reply;
+}
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