examples: Add keyboard controls to rx_ascii_art_dft

- Add keyboard controls for sample rate, gain, analog bandwidth,
frequency, as well as the display's dynamic range, reference level,
and frame rate.
- The current values for these properties, as well as the keys to
control them, are displayed in a small window at the top of the
display. This control window can be toggled by pressing 'c'

1 files changed, 116 insertions, 3 deletions

diff --git a/host/examples/rx_ascii_art_dft.cpp b/host/examples/rx_ascii_art_dft.cpp
index e242dbcd6..f37f4694e 100644
--- a/host/examples/rx_ascii_art_dft.cpp
+++ b/host/examples/rx_ascii_art_dft.cpp
@@ -27,8 +27,9 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //variables to be set by po
     std::string args, ant, subdev, ref;
     size_t num_bins;
-    double rate, freq, gain, bw, frame_rate;
+    double rate, freq, gain, bw, frame_rate, step;
     float ref_lvl, dyn_rng;
+    bool show_controls;
 
     //setup the program options
     po::options_description desc("Allowed options");
@@ -48,6 +49,8 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
         ("ref-lvl", po::value<float>(&ref_lvl)->default_value(0), "reference level for the display (dB)")
         ("dyn-rng", po::value<float>(&dyn_rng)->default_value(60), "dynamic range for the display (dB)")
         ("ref", po::value<std::string>(&ref)->default_value("internal"), "reference source (internal, external, mimo)")
+        ("step", po::value<double>(&step)->default_value(1e6), "tuning step for rate/bw/freq")
+        ("show-controls", po::value<bool>(&show_controls)->default_value(true), "show the keyboard controls")
         ("int-n", "tune USRP with integer-N tuning")
     ;
     po::variables_map vm;
@@ -98,6 +101,8 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
         std::cout << boost::format("Setting RX Gain: %f dB...") % gain << std::endl;
         usrp->set_rx_gain(gain);
         std::cout << boost::format("Actual RX Gain: %f dB...") % usrp->get_rx_gain() << std::endl << std::endl;
+    } else {
+        gain = usrp->get_rx_gain();
     }
 
     //set the analog frontend filter bandwidth
@@ -105,6 +110,8 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
         std::cout << boost::format("Setting RX Bandwidth: %f MHz...") % (bw/1e6) << std::endl;
         usrp->set_rx_bandwidth(bw);
         std::cout << boost::format("Actual RX Bandwidth: %f MHz...") % (usrp->get_rx_bandwidth()/1e6) << std::endl << std::endl;
+    } else {
+        bw = usrp->get_rx_bandwidth();
     }
 
     //set the antenna
@@ -169,20 +176,126 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
             ascii_art_dft::log_pwr_dft(&buff.front(), num_rx_samps)
         );
         std::string frame = ascii_art_dft::dft_to_plot(
-            lpdft, COLS, LINES,
+            lpdft, COLS, (show_controls ? LINES-6 : LINES),
             usrp->get_rx_rate(),
             usrp->get_rx_freq(),
             dyn_rng, ref_lvl
         );
 
+        std::string border = std::string((COLS), '-');
+
         //curses screen handling: clear and print frame
         clear();
+
+        if (show_controls) {
+            printw("%s", border.c_str());
+            printw("[f-F]req: %4.3f MHz   |   [r-R]ate: %2.2f Msps   |"
+                   "   [b-B]w: %2.2f MHz   |   [g-G]ain: %2.0f dB\n\n",
+                   freq/1e6, rate/1e6, bw/1e6, gain);
+            printw("[d-D]yn Range: %2.0f dB    |   Ref [l-L]evel: %2.0f dB   |"
+                   "   fp[s-S] : %2.0f   |   [t-T]uning step: %3.3f M\n",
+                   dyn_rng, ref_lvl, frame_rate, step/1e6);
+            printw("(press c to toggle controls)\n");
+            printw("%s", border.c_str());
+        }
         printw("%s", frame.c_str());
 
         //curses key handling: no timeout, any key to exit
         timeout(0);
         int ch = getch();
-        if (ch != KEY_RESIZE and ch != ERR) break;
+
+        // Key handling.
+        if (ch == 'r') {
+            rate -= step;
+            usrp->set_rx_rate(rate);
+            freq = usrp->get_rx_freq();
+        }
+
+        else if (ch == 'R') {
+            rate += step;
+            usrp->set_rx_rate(rate);
+            freq = usrp->get_rx_freq();
+        }
+
+        else if (ch == 'g') {
+            gain -= 1;
+            usrp->set_rx_gain(gain);
+            gain = usrp->get_rx_gain();
+        }
+
+        else if (ch == 'G') {
+            gain += 1;
+            usrp->set_rx_gain(gain);
+            gain = usrp->get_rx_gain();
+        }
+
+        else if (ch == 'b') {
+            bw -= step;
+            usrp->set_rx_bandwidth(bw);
+            bw = usrp->get_rx_bandwidth();
+        }
+
+        else if (ch == 'B') {
+            bw += step;
+            usrp->set_rx_bandwidth(bw);
+            bw = usrp->get_rx_bandwidth();
+        }
+
+        else if (ch == 'f') {
+            freq -= step;
+            usrp->set_rx_freq(freq);
+            freq = usrp->get_rx_freq();
+        }
+
+        else if (ch == 'F') {
+            freq += step;
+            usrp->set_rx_freq(freq);
+            freq = usrp->get_rx_freq();
+        }
+
+        else if (ch == 'l') ref_lvl -= 10;
+        else if (ch == 'L') ref_lvl += 10;
+        else if (ch == 'd') dyn_rng -= 10;
+        else if (ch == 'D') dyn_rng += 10;
+        else if (ch == 's') {
+            if (frame_rate > 1) {
+                frame_rate -= 1;
+            }
+        }
+        else if (ch == 'S') {
+            frame_rate += 1;
+        }
+        else if (ch == 't') {
+            if (step > 1) {
+                step /= 2;
+            }
+        }
+        else if (ch == 'T') step *= 2;
+        else if (ch == 'c' || ch == 'C') {
+            show_controls = !show_controls;
+        }
+        
+        // Arrow keypress generates 3 characters:
+        // '\033', '[', 'A'/'B'/'C'/'D' for Up / Down / Right / Left
+        else if (ch == '\033') {
+            getch();
+            switch(getch()) {
+                case 'A':
+                case 'C':
+                    freq += step;
+                    usrp->set_rx_freq(freq);
+                    freq = usrp->get_rx_freq();
+                    break;
+
+                case 'B':
+                case 'D':
+                    freq -= step;
+                    usrp->set_rx_freq(freq);
+                    freq = usrp->get_rx_freq();
+                    break;
+            }
+        }
+        else if (ch != KEY_RESIZE and ch != ERR) break;
     }
 
     //------------------------------------------------------------------