v.0.0.2 --- basic SDR capability added

main.c

@@ -1,9 +1,14 @@
+/* abandon all hope, this shit is a mess */
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <math.h>
+#include <unistd.h>
 #include <ncurses.h>
+#include <rtl-sdr.h>
 
-/* define ANSI escape chars */
+/* define ANSI escape chars and math */
 #define RESET "\033[0m"
 #define BOLD "\033[1m"
 #define UNDERLINE "\033[4m"
@@ -26,8 +31,16 @@
 #define BG_CYAN "\033[46m"
 #define BG_WHITE "\033[47m"
 
-/* declare global constants */
+#define M_PI 3.14159265358979323846
 
+/* declare global variables */
+
+rtlsdr_dev_t *dev = NULL;
+uint32_t device_index = 0;
+uint32_t MHz = 1000000;
+uint32_t kHz = 1000;
+uint32_t bandwidth;
+uint32_t center_freq;
 
 /* declare reusable functions */
 
@@ -78,6 +91,23 @@ void util_check() {
     }
 }
 
+void rtl_sdr_check() {
+    rtlsdr_open;
+    int index;
+    const char* device_name;
+    char serial[256], product[256], manufact[256];
+    device_name = rtlsdr_get_device_name(device_index);
+    rtlsdr_get_device_usb_strings(index, manufact, product, serial);
+    printf("device name: " GREEN);
+    printf(device_name);
+    printf("\n" RESET);
+    printf(YELLOW"serial: %s\n", serial);
+    printf("product: %s\n", product);
+    printf("manufacturer: %s\n", manufact);
+    printf(RESET);
+    rtlsdr_close;
+}
+
 
 /* making sure program has everything it needs to run, more checks will be introduced as capabilities are added */
 void startup_checks() {
@@ -102,23 +132,113 @@ void startup_checks() {
     printf(MAGENTA"UTILITIES\n\n"RESET);
     util_check();
     printf("----------------------------------------------------------------------\n");
+    printf(MAGENTA"SOFTWARE-DEFINED RADIO\n\n"RESET);
+    rtl_sdr_check();
+    printf("----------------------------------------------------------------------\n");
     printf(MAGENTA"all checks finished!\n"RESET);
     printf("######################################################################\n");
+    printf(GREEN"initializing RTL-SDR...\n"RESET);
+    rtlsdr_open(&dev, device_index);
+}
+
+/* signal analysis function */
+void fourier_transform(unsigned char *buf, double *out, int n) {
+    for (int k = 0; k < n; k++) {
+        double real = 0.0;
+        double imag = 0.0;
+        for (int t = 0; t < n; t++) {
+            double angle = 2 * M_PI * t * k / n;
+            real += buf[t] * cos(angle);
+            imag -= buf[t] * sin(angle);
+        }
+        out[k] = sqrt(real * real + imag * imag);
+    }
 }
 
 /* define functions for dashboard - WIP */
 
-/*
+void init_colors() {
+    start_color();
+    init_pair(1, COLOR_RED, COLOR_BLACK);
+    init_pair(2, COLOR_GREEN, COLOR_BLACK);
+    init_pair(3, COLOR_YELLOW, COLOR_BLACK);
+    init_pair(4, COLOR_BLUE, COLOR_BLACK);
+    init_pair(5, COLOR_MAGENTA, COLOR_BLACK);
+    init_pair(6, COLOR_CYAN, COLOR_BLACK);
+    init_pair(7, COLOR_WHITE, COLOR_BLACK);
+}
+
+void draw_bar_graph(double *data, int size) {
+    clear();
+    double max_value = 0.0;
+    attron(COLOR_PAIR(6));
+    printw("center frequency: %.3f MHz    gain: %d    bandwidth: %.3f MHz", center_freq / (double)MHz, rtlsdr_get_tuner_gain(dev), bandwidth / (double)MHz);
+    attroff(COLOR_PAIR(6));
+    double bottom = center_freq - bandwidth / 2.0;
+    double step = bandwidth / (double)size;
+    for (int i = 0; i < size; i++) {
+        if (data[i] > max_value) {
+            max_value = data[i];
+        }
+    }
+    attron(COLOR_PAIR(4));
+    for (int i = 0; i < size; i++) {
+        mvprintw(i + 1, 0, "%.3f MHz: ", bottom / (double)MHz + i * step / (double)MHz);
+        for (int j = 0; j < data[i] * 50 / max_value; j++) {
+            printw(">");
+        }
+    }
+    attroff(COLOR_PAIR(4));
+    refresh();
+}
+
+
+/* define rtl-sdr specific functions and general SDR workflow - WIP */
+
+void rtl_sdr_processing(unsigned char *buf, int buffer_length) {
+    int n = buffer_length;
+    double *out = (double *)malloc(n * sizeof(double));
+    fourier_transform(buf, out, n);
+    /* debug
+    for (int i = 0; i < n; i++) {
+        printf("%f\n", out[i]);
+    } */
+    draw_bar_graph(out, n);
+    free(out);
+}
+
+void rtl_sdr_waterfall() {
+    bandwidth = 10*MHz;
+    rtlsdr_set_tuner_bandwidth(dev, bandwidth);
+    uint32_t buffer_length = 40, n_read = 10; // example buffer length
+    unsigned char *buffer = (unsigned char *)malloc(buffer_length);
+    rtlsdr_set_center_freq(dev, 104*MHz); //104MHz for testing purposes
+    center_freq = rtlsdr_get_center_freq(dev);
+    rtlsdr_read_sync(dev, buffer, buffer_length, &n_read);
+    rtl_sdr_processing(buffer, buffer_length);
+    usleep(500000);
+}
+
+/* main dashboard function */
+
 void start_dashboard() {
     initscr();
     cbreak();
     noecho();
+    init_colors();
+    do
+    {
+        rtl_sdr_waterfall();
+    } while (true);
+    rtlsdr_close(dev);
+    endwin();
 }
-*/
 
 
 int main() {
     startup_screen();
     startup_checks();
+    start_dashboard();
+
     return 0;
 }