separate the gqrx protocol

.gitignore

@@ -72,4 +72,5 @@ CTestTestfile.cmake
 
 bin
 build
+gqrx-scan
 

.vscode/tasks.json

@@ -2,15 +2,26 @@
     // See https://go.microsoft.com/fwlink/?LinkId=733558
     // for the documentation about the tasks.json format
     "version": "2.0.0",
+    "options": {
+            "cwd": "${workspaceRoot}/bin/Debug"
+    },
+
     "tasks": [
         {
             "taskName": "Build",
-            "command": "gcc -g -o gqrx-scan gqrx-scan.c -lm",
+            "command": "make",
             "type": "shell",
             "group": {
                 "kind": "build",
                 "isDefault": true
             }
+        },
+        {
+            "taskName": "Clean",
+            "command": "make clean",
+            "type": "shell",
+            "group": "build",
+            "problemMatcher": []
         }
     ]
 }

CMakeLists.txt

@@ -8,6 +8,6 @@ set(LIBRARY_OUTPUT_PATH ${CMAKE_BINARY_DIR}/${CMAKE_BUILD_TYPE} CACHE PATH "Libr
 
 # The following folder will be included
 include_directories("${PROJECT_SOURCE_DIR}")
-add_executable(gqrx-scan ${PROJECT_SOURCE_DIR}/gqrx-scan.c)
+add_executable(gqrx-scan ${PROJECT_SOURCE_DIR}/gqrx-scan.c ${PROJECT_SOURCE_DIR}/gqrx-prot.c)
 target_link_libraries(gqrx-scan m)
 install (TARGETS gqrx-scan DESTINATION bin)

gqrx-prot.c

@@ -0,0 +1,177 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h> 
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <stdbool.h>
+#include <linux/limits.h>
+#include <math.h>
+#include "gqrx-prot.h"
+
+// 
+// error - wrapper for perror
+//
+void error(char *msg) {
+    perror(msg);
+    exit(0);
+}
+
+//
+// Connect
+//
+int Connect (char *hostname, int portno)
+{
+    int sockfd, n;
+    struct sockaddr_in serveraddr;
+    struct hostent *server;
+
+
+    /* socket: create the socket */
+    sockfd = socket(AF_INET, SOCK_STREAM, 0);
+    if (sockfd < 0) 
+        error("ERROR opening socket");
+
+    /* gethostbyname: get the server's DNS entry */
+    server = gethostbyname(hostname);
+    if (server == NULL) {
+        fprintf(stderr,"ERROR, no such host as %s\n", hostname);
+        exit(0);
+    }
+
+    /* build the server's Internet address */
+    bzero((char *) &serveraddr, sizeof(serveraddr));
+    serveraddr.sin_family = AF_INET;
+    bcopy((char *)server->h_addr, 
+	  (char *)&serveraddr.sin_addr.s_addr, server->h_length);
+    serveraddr.sin_port = htons(portno);
+
+    /* connect: create a connection with the server */
+    if (connect(sockfd, (const struct sockaddr *) &serveraddr, sizeof(serveraddr)) < 0) 
+      error("ERROR connecting");
+
+    return sockfd;
+}
+//
+// Send
+//
+bool Send(int sockfd, char *buf)
+{
+    int n;
+
+    n = write(sockfd, buf, strlen(buf));
+    if (n < 0) 
+      error("ERROR writing to socket");
+    return true;
+}
+
+//
+// Recv
+//
+bool Recv(int sockfd, char *buf)
+{
+    int n;
+
+    n = read(sockfd, buf, BUFSIZE);
+    if (n < 0) 
+      error("ERROR reading from socket");
+    buf[n]= '\0';
+    return true;
+}
+
+
+//
+// GQRX Protocol
+//
+bool GetCurrentFreq(int sockfd, long *freq)
+{
+    char buf[BUFSIZE];
+
+    Send(sockfd, "f\n");
+    Recv(sockfd, buf);
+
+    if (strcmp(buf, "RPRT 1") == 0 )
+        return false;
+
+    sscanf(buf, "%ld", freq);
+    return true;
+}
+bool SetFreq(int sockfd, long freq)
+{
+    char buf[BUFSIZE];
+
+    sprintf (buf, "F %ld\n", freq);
+    Send(sockfd, buf);
+    Recv(sockfd, buf);
+
+    if (strcmp(buf, "RPRT 1") == 0 )
+        return false;
+
+    long freq_current = 0;
+    do
+    {
+        GetCurrentFreq(sockfd, &freq_current);
+    } while (freq_current != freq);
+
+    return true;
+}
+
+bool GetSignalLevel(int sockfd, double *dBFS)
+{
+    char buf[BUFSIZE];
+
+    Send(sockfd, "l\n");
+    Recv(sockfd, buf);
+
+    if (strcmp(buf, "RPRT 1") == 0 )
+        return false;
+
+    sscanf(buf, "%lf", dBFS);
+    *dBFS = round((*dBFS) * 10)/10;
+
+    if (*dBFS == 0.0)
+        return false;
+    return true;
+}
+
+bool GetSquelchLevel(int sockfd, double *dBFS)
+{
+    char buf[BUFSIZE];
+
+    Send(sockfd, "l SQL\n");
+    Recv(sockfd, buf);
+
+    if (strcmp(buf, "RPRT 1") == 0 )
+        return false;
+
+    sscanf(buf, "%lf", dBFS);
+    *dBFS = round((*dBFS) * 10)/10;
+
+    return true;
+}
+//
+// GetSignalLevelEx
+// Get a bunch of sample with some delay and calculate the mean value
+//
+bool GetSignalLevelEx(int sockfd, double *dBFS, int n_samp)
+{
+    double temp_level;
+    *dBFS = 0;
+    int errors = 0;
+    for (int i = 0; i < n_samp; i++)
+    {
+        if ( GetSignalLevel(sockfd, &temp_level) )
+            *dBFS = *dBFS + temp_level; 
+        else
+            errors++;
+        usleep(1000);
+    }
+    *dBFS = *dBFS / (n_samp - errors);
+    return true;
+}

gqrx-prot.h

@@ -0,0 +1,43 @@
+#ifndef _GQRX_PROT_H_
+#define _GQRX_PROT_H_
+
+#define BUFSIZE         1024
+#define FREQ_MAX        4096
+#define SAVED_FREQ_MAX  1000
+#define TAG_MAX         100
+
+
+
+
+// 
+// error - wrapper for perror
+//
+void error(char *msg);
+
+//
+// Connect
+//
+int Connect (char *hostname, int portno);
+
+//
+// Send
+//
+bool Send(int sockfd, char *buf);
+
+//
+// Recv
+//
+bool Recv(int sockfd, char *buf);
+
+//
+// GQRX Protocol
+//
+bool GetCurrentFreq(int sockfd, long *freq);
+bool SetFreq(int sockfd, long freq);
+bool GetSignalLevel(int sockfd, double *dBFS);
+bool GetSquelchLevel(int sockfd, double *dBFS);
+bool GetSignalLevelEx(int sockfd, double *dBFS, int n_samp);
+
+
+
+#endif /* _GQRX_PROT_H_ */