Fixes output formatting and variable initialization, moving config to separate file, project folder correctly named, hopefully fixes network crashes

The formatting and variable initialization fixes should fix issue #1 (closed) and #3 (closed) . Note that it should be tested (together with the Python code) before merging. Fixing #3 (closed) will make the FESA class easier to write, as I discovered when writing the Python client.

Also fixes #5 (closed), which means that clients can impose timeouts of how often they expect to see data over a TCP channel (by default every 10 sec).

This merge request hopefully also fixes the random crashes seen in CLEAR (but not on the testbench in Oslo).

Also included is a change in the location of the config variables, which are now in a separate .h file.

Finally the Arduino sources have been moved into an appropriately named subfolder, in order to avoid needing to change the name of the git repo folder after git clone.

This is all done in one big merge request in order to avoid having to test multiple times.

PositionGaugeServer/PositionGaugeServer.ino

@@ -2,6 +2,13 @@
  * Server for transmitting multiple Mitutoyo position gauge measurements over ethernet.
  * Access via HTTP on TCP port 80, or very simple text protocol (telnet-like), one port per device.
  * 
+ * Example for accessing over text interface (best for machine clients):
+ *  nc 192.168.1.31 21
+ * or
+ *  nc 192.168.1.31 22
+ * Netcat (nc) is the best client: it is a clean TCP client,
+ * which makes no attempts to negotiate anything.
+ *  
  * Kyrre Ness Sjobak, 15 Feb 2021
  * University of Oslo / CERN
  * 
@@ -18,54 +25,13 @@
 #include <SPI.h>
 #include <Ethernet.h>
 
-// ***** Mitutoyo instrument configuration *****
-
-const uint8_t numCh = 2; //How many instruments connected
-                         // Instruments are configured by arrays
-                         // pinREQ / pinDAT / pinCLK / srvTXT_port / srvTXT
-                         // Remember to update if changing the config!
-//Arduino pins
-// Used for Ethernet shield -- AVOID:
-// 4/10/11/12/13 (UNO)
-// 50/51/52/10/4 (Mega)
-const uint8_t pinREQ[numCh] = {5,7};
-const uint8_t pinDAT[numCh] = {2,8};
-const uint8_t pinCLK[numCh] = {3,9};
-
-//Uncomment this to enable the "dummy reader" code instead of the SPC protocol interface
-// This disables the actual reading of the instrument,
-// however pins are still configured on start
-// This enables debugging of the network code if no Mitutoyo instrument is connected.
-//#define DUMMY_READER
-
-// ***** NETWORK CONFIG ************************
-// *** MAC ADDRESS FOR THE ARDUINO ON THE PLASMA-LENS ***
-//byte mac[] = {0xA8, 0x61, 0x0A, 0xAE, 0x84, 0xED};
-
-// *** MAC ADDRESS FOR THE ARDUINO ON THE CLIC STRUCTURE ***
-byte mac[] = {0xA8, 0x61, 0x0A, 0xAE, 0x84, 0xEE};
-
-//To use DHCP or not to use DHCP, that's the question.
-#define USE_DHCP
-
-#ifndef USE_DHCP
-IPAddress ip(192, 168, 1, 177);
-IPAddress myDns(192, 168, 1, 1);
-IPAddress gateway(192, 168, 1, 1);
-IPAddress subnet(255, 255, 0, 0);
-#endif
-
-// ***** OTHER CONFIG ***************************
-const unsigned long update_interval     = 1000; //[ms] How often to loop
-                                                // (poll sensors, check for new network clients,
-                                                //  feed data to network clients, DHCP housekeeping)
-const unsigned long WEB_update_interval = 5;    //[s]  WEB requests are heavy, not too often is good.
-const unsigned long SPC_timeout         = 200;  //[ms] Experimentally verified to be OK.
-const unsigned long WEB_timeout         = 700;  //[ms] Max time allowed waiting for web client
+//This file holds all the configurations
+// to be modified for deployment
+#include "PositionGaugeServer_config.h"
 
 // ***** GLOBAL VARIABLES ***********************
 
-unsigned long prevUpdateTime;
+unsigned long prevUpdateTime = 0;
 
 float measData[numCh];
 bool  measDataFresh[numCh];
@@ -83,16 +49,9 @@ EthernetServer srvTXT[numCh] = {
 EthernetClient clients[MAX_SOCK_NUM];
 uint8_t        clients_ch[MAX_SOCK_NUM]; //which channel does a particular client belong to?
 
+unsigned long srvTXT_prevUpdateTime[numCh];
 
-
-
-
-
-
-
-
-
-// ***** CODE -- DO NOT CHANGE *******************
+// ***** CODE ************************************
 
 void setup() {
 
@@ -178,6 +137,7 @@ void setup() {
   srvWEB.begin();
   for (uint8_t ch = 0; ch<numCh; ch++) {
     srvTXT[ch].begin();
+    srvTXT_prevUpdateTime[ch] = 0;
   }
   
   //General
@@ -192,7 +152,8 @@ void setup() {
   }
 
   
-  Serial.print("Update interval  "); Serial.print(update_interval); Serial.println(" [ms]");
+  Serial.print("Poll interval  "); Serial.print(update_interval); Serial.println(" [ms]");
+  Serial.print("Max. interval  "); Serial.print(srvTXT_max_interval); Serial.println(" [ms]");
   Serial.println();
 }
 
@@ -453,8 +414,9 @@ void HTTPserver () {
         client.println("<p>");
         client.print("IP address:         "); client.print(Ethernet.localIP()); client.println("<br>");
         client.print("No. channels:       "); client.print(numCh); client.println("<br>");
-        client.print("Update interval     "); client.print(update_interval); client.println(" [ms]<br>");
-        client.print("WEB update interval "); client.print(WEB_update_interval); client.println(" [s]<br>");
+        client.print("Poll interval:      "); client.print(update_interval); client.println(" [ms]<br>");
+        client.print("WEB update interval:"); client.print(WEB_update_interval); client.println(" [s]<br>");
+        client.print("Max. interval:      "); client.print(srvTXT_max_interval); client.println(" [ms]");
         client.print("Internal time:      "); client.print(millis()); client.println(" [ms]<br>");
 
         client.println("</p>");
@@ -557,6 +519,10 @@ void TXTserver (uint8_t ch) {
           //clients[i].println(ch);
   
           //Feed the new client some data right away
+          if(measData[ch] >= 0) {
+            //Add the '+' so that the string is always the same length
+            clients[i].print('+');
+          }
           clients[i].print(measData[ch],3);
           if (measDataIsValid[ch]) {
             if (measDataIsMm[ch]) {
@@ -591,10 +557,16 @@ void TXTserver (uint8_t ch) {
     }
   }
   
-  //3. If fresh data is available, send it!
-  if (measDataFresh[ch]) {
+  //3. If fresh data is available or too long since last update, send it!
+  unsigned long timeSinceLastUpdate = millis() - srvTXT_prevUpdateTime[ch];
+  if (measDataFresh[ch] or (timeSinceLastUpdate >= srvTXT_max_interval)) {
+    srvTXT_prevUpdateTime[ch] = millis();
     for (byte i = 0; i < MAX_SOCK_NUM; i++) {
       if (clients[i] && (clients_ch[i]==ch)) {
+        if(measData[ch] >= 0) {
+          //Add the '+' so that the string is always the same length
+          clients[i].print('+');
+        }
         clients[i].print(measData[ch],3);
         if (measDataIsValid[ch]) {
           if (measDataIsMm[ch]) {
@@ -615,12 +587,11 @@ void TXTserver (uint8_t ch) {
   for (byte i = 0; i < MAX_SOCK_NUM; i++) { 
     if ( clients[i] && (clients_ch[i]==ch) && !clients[i].connected() ) {
       clients[i].stop();
-      clients_ch[i]=0;
 
-        Serial.print("Closed connection for ch=");
-        Serial.print(ch);
-        Serial.print(" slot ");
-        Serial.println(i);
+      Serial.print("Closed connection for ch=");
+      Serial.print(ch);
+      Serial.print(" slot ");
+      Serial.println(i);
     }
   }
 }
@@ -669,4 +640,3 @@ void DHCPhousekeeping() {
   }
 }
 #endif
-