From ddd3cdf8fc00adefeb326b714f6041751a4e80f3 Mon Sep 17 00:00:00 2001
From: Lars Beemster <l.j.beemster@gmail.com>
Date: Wed, 30 May 2018 18:40:35 +0200
Subject: [PATCH] keep alive and accept some input from keyboard

---
 fl2k-psk.c | 59 ++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 44 insertions(+), 15 deletions(-)

diff --git a/fl2k-psk.c b/fl2k-psk.c
index 3965764..eaccfcd 100644
--- a/fl2k-psk.c
+++ b/fl2k-psk.c
@@ -23,6 +23,10 @@ uint32_t fl2k_dev_idx = 0;
 // Catches ^C and stops
 static void sighandler(int signum) {
 	cout << "Signal caught, exiting!" << endl;
+	
+	fl2k_stop_tx(fl2k_dev);
+	fl2k_close(fl2k_dev);
+
 	exit(0);
 }
 
@@ -62,32 +66,57 @@ void attach_sighandlers() {
 	sigaction(SIGPIPE, &sigign, nullptr);
 }
 
+void set_freq_carrier(uint32_t freq) {
+	uint32_t samplerate = freq * 2; // sample rate twice the frequency gives the smoothest output (TODO: experiment)
 
-int main(int argc, char **argv) {
-	uint32_t freq_carrier = 14000000;
-	uint32_t samplerate = freq_carrier * 2; // sample rate twice the frequency gives the smoothest output (TODO: experiment)
+	// Set the sample rate
+	int r = fl2k_set_sample_rate(fl2k_dev, samplerate);
+	if (r < 0) {
+		cout << "WARNING: Failed to set sample rate. " << r << endl;
+	}
+
+	/* read back actual frequency */
+	samplerate = fl2k_get_sample_rate(fl2k_dev);
+	cout << "Actual sample rate = " << samplerate << endl;
+}
 
+
+int main(int argc, char **argv) {
 	attach_sighandlers();
 	init_txbuffer();
 	fl2k_open(&fl2k_dev, fl2k_dev_idx);
 	
-	if (!fl2k_dev) {
+	if(!fl2k_dev) {
 		cout << "Failed to open fl2k device #" << fl2k_dev_idx << endl;
-		exit(0);
 	}
-	cout << "Opened device" << endl;
-
-	int r = fl2k_start_tx(fl2k_dev, fl2k_callback, nullptr, 0);
+	else {
+		cout << "Opened device" << endl;
+	
+		int r = fl2k_start_tx(fl2k_dev, fl2k_callback, nullptr, 0);
+		set_freq_carrier(14000000);
+	}
 
-	// Set the sample rate
-	r = fl2k_set_sample_rate(fl2k_dev, samplerate);
-	if (r < 0) {
-		cout << "WARNING: Failed to set sample rate. " << r << endl;
+	cout << "Press u,d,q to raise or lower frequency, or quit: " << flush;
+	char c;
+	while(cin.get(c)) {
+		switch(c) {
+		case 'u':
+			set_freq_carrier(fl2k_get_sample_rate(fl2k_dev) + 1000000);
+			break;
+		case 'd':
+			set_freq_carrier(fl2k_get_sample_rate(fl2k_dev) - 1000000);
+			break;
+		case 'q':
+			exit(0);
+			break;
+		default:
+			break;
+		}
+		
+		cin.ignore();
+		cout << "> " << flush;
 	}
 
-	/* read back actual frequency */
-	samplerate = fl2k_get_sample_rate(fl2k_dev);
-	cout << "Actual sample rate = " << samplerate << endl;
 
 	return 0;
 }