From faefaed63cb9bb430216e1f418cba08c72020036 Mon Sep 17 00:00:00 2001
From: Tristan Krause <tristan.krause@stud.htwk-leipzig.de>
Date: Thu, 16 May 2019 11:03:49 +0200
Subject: [PATCH] nullpointer check added

---
 control/examples/pegel/Makefile |  2 +-
 control/examples/pegel/main.cpp | 11 ++++------
 control/src/drv/b15f.cpp        | 38 ++++++++++++++++++++++++++-------
 3 files changed, 35 insertions(+), 16 deletions(-)

diff --git a/control/examples/pegel/Makefile b/control/examples/pegel/Makefile
index fc23b62..8000d6e 100644
--- a/control/examples/pegel/Makefile
+++ b/control/examples/pegel/Makefile
@@ -24,7 +24,7 @@ help:
 	
 clean:
 	@echo "Cleaning..."
-	rm -f $(OBJECTS) $(OUT)
+	rm -f $(OBJECTS) $(OUT) *.bin gnuplotscript.gp
 
 .cpp.o:
 	$(COMPILE) -c $< -o $@
diff --git a/control/examples/pegel/main.cpp b/control/examples/pegel/main.cpp
index e3eb666..960b8ad 100644
--- a/control/examples/pegel/main.cpp
+++ b/control/examples/pegel/main.cpp
@@ -3,7 +3,7 @@
 #include <b15f/b15f.h>
 #include <b15f/plottyfile.h>
 
-constexpr char * PLOT_FILE = "plot.bin";
+const char PLOT_FILE[] = "plot.bin";
 
 int main()
 {
@@ -12,7 +12,6 @@ int main()
 	PlottyFile pf;
 	
 	uint16_t ba[1024];
-	uint16_t bb[1024];
 	
 	const uint16_t sample_count = 1024;
 	const uint16_t delta = 1;
@@ -31,14 +30,12 @@ int main()
 	uint8_t curve = 0;
 		
 	
-    drv.analogSequence(0, &ba[0], 0, 1, &bb[0], 0, 0, delta, sample_count);
+    drv.analogSequence(0, &ba[0], 0, 1, nullptr, 0, 0, delta, sample_count);
     
     for(uint16_t x = 0; x < sample_count * delta; x += delta)
     {
-		drv.analogWrite0(x);
-		uint16_t y = drv.analogRead(0);
-		std::cout << x << " - " << y << std::endl;
-        pf.addDot(Dot(x, y, curve));
+		std::cout << x << " - " << ba[x] << std::endl;
+        pf.addDot(Dot(x, ba[x], curve));
     }
     
 	// speichern und plotty starten
diff --git a/control/src/drv/b15f.cpp b/control/src/drv/b15f.cpp
index 3d5de24..22937e9 100644
--- a/control/src/drv/b15f.cpp
+++ b/control/src/drv/b15f.cpp
@@ -240,8 +240,12 @@ uint16_t B15F::analogRead(uint8_t channel)
 
 void B15F::analogSequence(uint8_t channel_a, uint16_t* buffer_a, uint32_t offset_a, uint8_t channel_b, uint16_t* buffer_b, uint32_t offset_b, uint16_t start, int16_t delta, uint16_t count)
 {
-	buffer_a += offset_a;
-	buffer_b += offset_b;
+	// check pointers
+	if(buffer_a)
+		buffer_a += offset_a;
+	if(buffer_b)
+		buffer_b += offset_b;
+	
 	
 	usart.clearInputBuffer();
 	usart.writeByte(RQ_ADC_DAC_STROKE);
@@ -249,15 +253,33 @@ void B15F::analogSequence(uint8_t channel_a, uint16_t* buffer_a, uint32_t offset
 	usart.writeByte(channel_b);
 	usart.writeInt(start);
 	usart.writeInt(static_cast<uint16_t>(delta));
-	usart.writeInt(count);
-	
+	usart.writeInt(count);	
 	
 	for(uint16_t i = 0; i < count; i++)
 	{
-		buffer_a[i] = usart.readInt();
-		buffer_b[i] = usart.readInt();
-		if(buffer_a[i] > 1023 || buffer_b[i] > 1023)
-			abort("Bad ADC data detected (2)");
+		if(buffer_a)
+		{
+			buffer_a[i] = usart.readInt();
+			
+			if(buffer_a[i] > 1023) // check for broken usart connection
+				abort("Bad ADC data detected (2)");
+		}
+		else
+		{
+			usart.readInt();
+		}
+		
+		if(buffer_b)
+		{
+			buffer_b[i] = usart.readInt();
+			
+			if(buffer_b[i] > 1023) // check for broken usart connection
+				abort("Bad ADC data detected (3)");
+		}
+		else
+		{
+			usart.readInt();
+		}
 	}
 	
 	uint8_t aw = usart.readByte();