Diff: main.cpp

Revision:

0:4f326062cb33

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Aug 03 10:17:41 2017 +0000
@@ -0,0 +1,85 @@
+/* ---------------------------------------
+   ---------------------------------------
+   Author: Joel Holland
+   Purpose: To have mbed send bytes of 
+            data to a TCP server.
+   Note: Do not update ethernetinterface.h
+         new repositories are broken.
+    --------------------------------------
+    -------------------------------------- */
+    
+#include "mbed.h"
+#include "EthernetInterface.h"
+
+EthernetInterface eth;    //ethernet object
+TCPSocketConnection socket;  //socket object
+Serial pc(USBTX,USBRX);      //interface with TeraTerm
+DigitalOut P17(p17);
+AnalogIn LM35(p15);
+DigitalOut P16(p16);
+DigitalOut P18(p18);
+DigitalOut P19(p19);
+DigitalOut P20(p20);
+
+static const char* ip = "10.58.92.178";
+static const char* mask = "255.255.192.0";
+static const char* gateway = "10.58.64.1";
+
+// A data structure of the data to send
+// In this case it's fairly pointless, you may as well just use a uint16_t[] directly in place of this
+// But if you package what you want into a structure then you don't need to change the 
+// transmission code if you change what is being sent, you just change the structure definition.
+typedef struct packetToSent_s {   
+uint8_t data[1];   //specify data types within the struct, in this case an 80 element array of 8-bit unsigned int
+} packetToSend_t;
+
+packetToSend_t dataOut;  //an instance of the packet to send
+
+int main()
+{    
+    pc.printf("This program constantly polls the temperature sensor\n\n");
+    pc.printf("and sends the data packets out through both USB and TCP.\n\n");
+    eth.init(ip,mask,gateway);  //static
+    wait(5);
+    eth.connect();
+    wait(5);    //allow the mbed time to be dynamically assigned an IP and to connect before printing IP address
+    pc.printf("IP address is %s\n\n", eth.getIPAddress()); //function in ethernet library to return string containing IP
+    pc.printf("Mask is is %s\n\n", eth.getNetworkMask());
+    pc.printf("Gateway is %s\n\n", eth.getGateway());
+    
+    socket.connect("10.58.74.19", 23);  //ip address of PC, and port to be listened to by the HOST     
+    wait(1);
+   
+    while(1) {
+            float tempC,mv,avgtemp;
+            //specify data to be sent. Here we would desire the output from the multiplexer.
+            for(int i=0;i<1;i++) {
+                float avg=0;
+                    for(int j=0;j<100;j++) {
+                         mv = ((LM35.read()-0.02)*3300);    //calibrate the analogue pin, multiply by reference voltage, convert to mv.
+                 //      pc.printf("voltage of sensor is %.2f",mv);
+                //       wait(1);
+                         tempC = mv/10;              //LM35 device has a 1 degree change for every 10mv, therefore divide by this to get temp in C.
+               //        pc.printf("temperature sample is %.2f C\t",tempC);  
+               //        wait(1);                                            
+                         avg=avg+tempC;
+                         wait(0.01); //take 100 samples at a rate of 1ms
+                    }
+            avgtemp=avg/100;
+            pc.printf("Temperature is %2.2f C\t\t\t", avgtemp);  
+            uint8_t b;
+            b=avgtemp; //remove offset from analogue pin, then convert to unsigned integer 8 bit (2 bytes). 
+            dataOut.data[i]=b;  //populate array with analogue readings from pin 17. Remove offset.
+            }
+
+    //send the data packet by passing a pointer to the start of the data, and specifying its size. 
+    
+    socket.send_all((char*)&dataOut,sizeof(packetToSend_t));
+    //socket.send_all((char*)&dataOut2,sizeof(packetToSend_t));  here we could send packets corresponding to different data types
+    }
+//ideally should check return value from send_all to verify no errors have occured.
+
+
+}
+
+