From 63c57d8a43828d4ec7fb0d3c4fcdaff4bddb2429 Mon Sep 17 00:00:00 2001
From: Tom Early <n7tae@tearly.net>
Date: Sat, 8 Jan 2022 04:10:24 -0700
Subject: [PATCH] now with a zero purge

---
 DV3003.cpp | 33 ++++++++++++++++++++++++---------
 DV3003.h   |  1 +
 Main.cpp   |  2 +-
 3 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/DV3003.cpp b/DV3003.cpp
index ccc17d2..a6131a1 100644
--- a/DV3003.cpp
+++ b/DV3003.cpp
@@ -138,14 +138,13 @@ bool CDV3003::OpenDevice(const std::string &ttyname, int baudrate)
 
 	if (SetBaudRate(baudrate))
 		return true;
-#ifdef DEBUG
 	std::cout << ttyname << " baudrate it set to " << baudrate << std::endl;
-#endif
 
 	devicepath.assign(ttyname);
-#ifdef DEBUG
 	std::cout << "Opened " << devicepath << " using fd " << fd << std::endl;
-#endif
+
+	if (Purge())
+		return true;
 
 	if (InitDV3003())
 		return true;
@@ -158,11 +157,31 @@ bool CDV3003::OpenDevice(const std::string &ttyname, int baudrate)
 	return false;
 }
 
+bool CDV3003::Purge()
+{
+	const char zeros[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+	// if there is a partial command in the input, this will clear it
+	for (unsigned int i=0; i<35; i++)
+	{
+		auto written = write(fd, zeros, sizeof(zeros));
+		if (0 > written)
+		{
+			std::cerr << "Cleanse failed to write zeros to " << devicepath << std::endl;
+			return true;
+		}
+		if (written < 10)
+		{
+			std::cerr << "On Cleanse pass " << i << ", only " << written << " bytes were written to " << devicepath << std::endl;
+		}
+	}
+	return false;
+}
+
 bool CDV3003::InitDV3003()
 {
 	SDV3003_Packet responsePacket, ctrlPacket;
 
-	// ********** hard reset *************
+	// ********** soft reset *************
     ctrlPacket.start_byte = PKT_HEADER;
     ctrlPacket.header.payload_length = htons(3);
     ctrlPacket.header.packet_type = PKT_CONTROL;
@@ -183,9 +202,7 @@ bool CDV3003::InitDV3003()
 	   std::cerr << "InitDV3003: invalid response to reset" << std::endl;
 	   return true;
 	}
-#ifdef DEBUG
 	std::cout << "Successfully reset " << devicepath << std::endl;
-#endif
 
 	// ********** turn off parity *********
 	ctrlPacket.header.payload_length = htons(4);
@@ -211,9 +228,7 @@ bool CDV3003::InitDV3003()
 		return true;
 	}
 
-#ifdef DEBUG
 	std::cout << "Successfully disabled parity on " << devicepath << std::endl;
-#endif
 
 	// ********* Product ID and Version *************
 	ctrlPacket.header.payload_length = htons(1);
diff --git a/DV3003.h b/DV3003.h
index 4ccba5e..d6debaf 100644
--- a/DV3003.h
+++ b/DV3003.h
@@ -125,6 +125,7 @@ private:
 	void ReadDevice();
 	bool SetBaudRate(int baudrate);
 	bool InitDV3003();
+	bool Purge();
 	bool ConfigureVocoder(uint8_t pkt_ch, Encoding type);
 	bool checkResponse(SDV3003_Packet &responsePacket, uint8_t response) const;
 	bool SendAudio(const uint8_t channel, const int16_t *audio) const;
diff --git a/Main.cpp b/Main.cpp
index 4a1b9e4..578ab7b 100644
--- a/Main.cpp
+++ b/Main.cpp
@@ -27,7 +27,7 @@ int main()
 	if (Controller.Start())
 		return EXIT_FAILURE;
 
-	std::cout << "Hybrid Transcoder version 1.0.0 successfully started" << std::endl;
+	std::cout << "Hybrid Transcoder version 0.0.0 successfully started" << std::endl;
 
 	pause();