ngscopeclient · May 24, 2020 · May 24, 2020 · May 24, 2020
diff --git a/scopemeasurements/CMakeLists.txt b/scopemeasurements/CMakeLists.txt
diff --git a/scopemeasurements/scopemeasurements.cpp b/scopemeasurements/scopemeasurements.cpp
diff --git a/scopemeasurements/scopemeasurements.h b/scopemeasurements/scopemeasurements.h
diff --git a/scopeprotocols/CMakeLists.txt b/scopeprotocols/CMakeLists.txt
@@ -34,8 +34,10 @@ set(SCOPEPROTOCOLS_SOURCES
 	JtagDecoder.cpp
 	MDIODecoder.cpp
 	MovingAverageDecoder.cpp
+	OvershootMeasurementDecoder.cpp
 	ParallelBusDecoder.cpp
 	PeriodMeasurementDecoder.cpp
+	PkPkMeasurementDecoder.cpp
 	RiseMeasurementDecoder.cpp
 	SincInterpolationDecoder.cpp
 	SPIDecoder.cpp
@@ -44,6 +46,7 @@ set(SCOPEPROTOCOLS_SOURCES
 	TopMeasurementDecoder.cpp
 	UARTDecoder.cpp
 	UartClockRecoveryDecoder.cpp
+	UndershootMeasurementDecoder.cpp
 	USB2ActivityDecoder.cpp
 	USB2PacketDecoder.cpp
 	USB2PCSDecoder.cpp

diff --git a/scopemeasurements/OvershootMeasurement.cpp → ...protocols/OvershootMeasurementDecoder.cpp b/scopemeasurements/OvershootMeasurement.cpp → ...protocols/OvershootMeasurementDecoder.cpp
@@ -2,7 +2,7 @@
 *                                                                                                                      *
 * ANTIKERNEL v0.1                                                                                                      *
 *                                                                                                                      *
-* Copyright (c) 2012-2019 Andrew D. Zonenberg                                                                          *
+* Copyright (c) 2012-2020 Andrew D. Zonenberg                                                                          *
 * All rights reserved.                                                                                                 *
 *                                                                                                                      *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the     *
@@ -27,68 +27,163 @@
 *                                                                                                                      *
 ***********************************************************************************************************************/
 
-/**
-	@file
-	@author Andrew D. Zonenberg
-	@brief Declaration of OvershootMeasurement
- */
-
-#include "scopemeasurements.h"
-#include "OvershootMeasurement.h"
+#include "scopeprotocols.h"
+#include "OvershootMeasurementDecoder.h"
 
 using namespace std;
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-// Construction/destruction
+// Construction / destruction
 
-OvershootMeasurement::OvershootMeasurement()
-	: FloatMeasurement(TYPE_PERCENTAGE)
+OvershootMeasurementDecoder::OvershootMeasurementDecoder(string color)
+	: ProtocolDecoder(OscilloscopeChannel::CHANNEL_TYPE_ANALOG, color, CAT_MEASUREMENT)
 {
-	//Configure for a single input
-	m_signalNames.push_back("Vin");
+	//Set up channels
+	m_signalNames.push_back("din");
 	m_channels.push_back(NULL);
+
+	m_midpoint = 0;
+	m_range = 1;
 }
 
-OvershootMeasurement::~OvershootMeasurement()
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Factory methods
+
+bool OvershootMeasurementDecoder::ValidateChannel(size_t i, OscilloscopeChannel* channel)
 {
+	if( (i == 0) && (channel->GetType() == OscilloscopeChannel::CHANNEL_TYPE_ANALOG) )
+		return true;
+	return false;
 }
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // Accessors
 
-Measurement::MeasurementType OvershootMeasurement::GetMeasurementType()
+void OvershootMeasurementDecoder::SetDefaultName()
 {
-	return Measurement::MEAS_VERT;
+	char hwname[256];
+	snprintf(hwname, sizeof(hwname), "Overshoot(%s)", m_channels[0]->m_displayname.c_str());
+	m_hwname = hwname;
+	m_displayname = m_hwname;
 }
 
-string OvershootMeasurement::GetMeasurementName()
+string OvershootMeasurementDecoder::GetProtocolName()
 {
 	return "Overshoot";
 }
 
-bool OvershootMeasurement::ValidateChannel(size_t i, OscilloscopeChannel* channel)
+bool OvershootMeasurementDecoder::IsOverlay()
 {
-	if( (i == 0) && (channel->GetType() == OscilloscopeChannel::CHANNEL_TYPE_ANALOG) )
-		return true;
+	//we create a new analog channel
+	return false;
+}
+
+bool OvershootMeasurementDecoder::NeedsConfig()
+{
+	//automatic configuration
 	return false;
 }
 
+double OvershootMeasurementDecoder::GetVoltageRange()
+{
+	return m_range;
+}
+
+double OvershootMeasurementDecoder::GetOffset()
+{
+	return -m_midpoint;
+}
+
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-// Measurement processing
+// Actual decoder logic
 
-bool OvershootMeasurement::Refresh()
+void OvershootMeasurementDecoder::Refresh()
 {
 	//Get the input data
 	if(m_channels[0] == NULL)
-		return false;
-	AnalogCapture* din = dynamic_cast<AnalogCapture*>(m_channels[0]->GetData());
-	if(din == NULL || (din->GetDepth() == 0))
-		return false;
-
-	//Calculate the worst case overshoot
-	float max = GetMaxVoltage(din);
-	float top = GetTopVoltage(din);
-	float base = GetBaseVoltage(din);
-	m_value = (max-top) / (top-base);
-	return true;
+	{
+		SetData(NULL);
+		return;
+	}
+	auto din = dynamic_cast<AnalogWaveform*>(m_channels[0]->GetData());
+	if(din == NULL)
+	{
+		SetData(NULL);
+		return;
+	}
+
+	//We need meaningful data
+	size_t len = din->m_samples.size();
+	if(len == 0)
+	{
+		SetData(NULL);
+		return;
+	}
+
+	//Figure out the nominal top of the waveform
+	float top = Measurement::GetTopVoltage(din);
+	float base = Measurement::GetBaseVoltage(din);
+	float midpoint = (top+base)/2;
+
+	//Create the output
+	auto cap = new AnalogWaveform;
+
+	float 		fmax = -FLT_MAX;
+	float		fmin =  FLT_MAX;
+
+	int64_t		tmax = 0;
+	float		vmax = 0;
+
+	//For each cycle, find how far we got above the top
+	for(size_t i=0; i < len; i++)
+	{
+		//If we're below the midpoint, reset everything and add a new sample
+		float v = din->m_samples[i];
+		if(v < midpoint)
+		{
+			//Add a sample for the current value (if any)
+			if(tmax > 0)
+			{
+				//Update duration of the previous sample
+				size_t off = cap->m_offsets.size();
+				if(off > 0)
+					cap->m_durations[off-1] = tmax - cap->m_offsets[off-1];
+
+				float value = vmax - top;
+				fmax = max(fmax, value);
+				fmin = min(fmin, value);
+
+				//Add the new sample
+				cap->m_offsets.push_back(tmax);
+				cap->m_durations.push_back(0);
+				cap->m_samples.push_back(value);
+			}
+
+			//Reset
+			tmax = 0;
+			vmax = -FLT_MAX;
+		}
+
+		//Accumulate the highest peak of this cycle
+		else
+		{
+			if(v > vmax)
+			{
+				tmax = din->m_offsets[i];
+				vmax = v;
+			}
+		}
+	}
+
+	m_range = fmax - fmin;
+	if(m_range < 0.025)
+		m_range = 0.025;
+	m_midpoint = (fmax + fmin) / 2;
+
+	SetData(cap);
+
+	//Copy start time etc from the input.
+	cap->m_timescale = din->m_timescale;
+	cap->m_startTimestamp = din->m_startTimestamp;
+	cap->m_startPicoseconds = din->m_startPicoseconds;
 }
diff --git a/scopemeasurements/UndershootMeasurement.h → scopeprotocols/OvershootMeasurementDecoder.h b/scopemeasurements/UndershootMeasurement.h → scopeprotocols/OvershootMeasurementDecoder.h
@@ -2,7 +2,7 @@
 *                                                                                                                      *
 * ANTIKERNEL v0.1                                                                                                      *
 *                                                                                                                      *
-* Copyright (c) 2012-2019 Andrew D. Zonenberg                                                                          *
+* Copyright (c) 2012-2020 Andrew D. Zonenberg                                                                          *
 * All rights reserved.                                                                                                 *
 *                                                                                                                      *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the     *
@@ -30,27 +30,36 @@
 /**
 	@file
 	@author Andrew D. Zonenberg
-	@brief Declaration of UndershootMeasurement
+	@brief Declaration of OvershootMeasurementDecoder
  */
-#ifndef UndershootMeasurement_h
-#define UndershootMeasurement_h
+#ifndef OvershootMeasurementDecoder_h
+#define OvershootMeasurementDecoder_h
 
-#include "../scopehal/Measurement.h"
+#include "../scopehal/ProtocolDecoder.h"
 
-class UndershootMeasurement : public FloatMeasurement
+class OvershootMeasurementDecoder : public ProtocolDecoder
 {
 public:
-	UndershootMeasurement();
-	virtual ~UndershootMeasurement();
+	OvershootMeasurementDecoder(std::string color);
 
-	virtual bool Refresh();
+	virtual void Refresh();
+
+	virtual bool NeedsConfig();
+	virtual bool IsOverlay();
+
+	static std::string GetProtocolName();
+	virtual void SetDefaultName();
+
+	virtual double GetVoltageRange();
+	virtual double GetOffset();
 
-	static std::string GetMeasurementName();
 	virtual bool ValidateChannel(size_t i, OscilloscopeChannel* channel);
 
-	virtual MeasurementType GetMeasurementType();
+	PROTOCOL_DECODER_INITPROC(OvershootMeasurementDecoder)
 
-	MEASUREMENT_INITPROC(UndershootMeasurement)
+protected:
+	double m_midpoint;
+	double m_range;
 };
 
 #endif
diff --git a/scopemeasurements/PkPkVoltageMeasurement.cpp → scopeprotocols/PkPkMeasurementDecoder.cpp b/scopemeasurements/PkPkVoltageMeasurement.cpp → scopeprotocols/PkPkMeasurementDecoder.cpp
@@ -2,7 +2,7 @@
 *                                                                                                                      *
 * ANTIKERNEL v0.1                                                                                                      *
 *                                                                                                                      *
-* Copyright (c) 2012-2019 Andrew D. Zonenberg                                                                          *
+* Copyright (c) 2012-2020 Andrew D. Zonenberg                                                                          *
 * All rights reserved.                                                                                                 *
 *                                                                                                                      *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the     *
@@ -27,65 +27,180 @@
 *                                                                                                                      *
 ***********************************************************************************************************************/
 
-/**
-	@file
-	@author Andrew D. Zonenberg
-	@brief Declaration of PkPkVoltageMeasurement
- */
-
-#include "scopemeasurements.h"
-#include "PkPkVoltageMeasurement.h"
+#include "scopeprotocols.h"
+#include "PkPkMeasurementDecoder.h"
 
 using namespace std;
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-// Construction/destruction
+// Construction / destruction
 
-PkPkVoltageMeasurement::PkPkVoltageMeasurement()
-	: FloatMeasurement(TYPE_VOLTAGE)
+PkPkMeasurementDecoder::PkPkMeasurementDecoder(string color)
+	: ProtocolDecoder(OscilloscopeChannel::CHANNEL_TYPE_ANALOG, color, CAT_MEASUREMENT)
 {
-	//Configure for a single input
-	m_signalNames.push_back("Vin");
+	//Set up channels
+	m_signalNames.push_back("din");
 	m_channels.push_back(NULL);
+
+	m_midpoint = 0;
+	m_range = 1;
 }
 
-PkPkVoltageMeasurement::~PkPkVoltageMeasurement()
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Factory methods
+
+bool PkPkMeasurementDecoder::ValidateChannel(size_t i, OscilloscopeChannel* channel)
 {
+	if( (i == 0) && (channel->GetType() == OscilloscopeChannel::CHANNEL_TYPE_ANALOG) )
+		return true;
+	return false;
 }
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // Accessors
 
-Measurement::MeasurementType PkPkVoltageMeasurement::GetMeasurementType()
+void PkPkMeasurementDecoder::SetDefaultName()
 {
-	return Measurement::MEAS_VERT;
+	char hwname[256];
+	snprintf(hwname, sizeof(hwname), "PkPk(%s)", m_channels[0]->m_displayname.c_str());
+	m_hwname = hwname;
+	m_displayname = m_hwname;
 }
 
-string PkPkVoltageMeasurement::GetMeasurementName()
+string PkPkMeasurementDecoder::GetProtocolName()
 {
-	return "Pk-Pk";
+	return "Peak-to-Peak";
 }
 
-bool PkPkVoltageMeasurement::ValidateChannel(size_t i, OscilloscopeChannel* channel)
+bool PkPkMeasurementDecoder::IsOverlay()
 {
-	if( (i == 0) && (channel->GetType() == OscilloscopeChannel::CHANNEL_TYPE_ANALOG) )
-		return true;
+	//we create a new analog channel
 	return false;
 }
 
+bool PkPkMeasurementDecoder::NeedsConfig()
+{
+	//automatic configuration
+	return false;
+}
+
+double PkPkMeasurementDecoder::GetVoltageRange()
+{
+	return m_range;
+}
+
+double PkPkMeasurementDecoder::GetOffset()
+{
+	return -m_midpoint;
+}
+
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-// Measurement processing
+// Actual decoder logic
 
-bool PkPkVoltageMeasurement::Refresh()
+void PkPkMeasurementDecoder::Refresh()
 {
 	//Get the input data
 	if(m_channels[0] == NULL)
-		return false;
-	AnalogCapture* din = dynamic_cast<AnalogCapture*>(m_channels[0]->GetData());
-	if(din == NULL || (din->GetDepth() == 0))
-		return false;
-
-	//Calculate the global peak to peak
-	m_value = GetMaxVoltage(din) - GetMinVoltage(din);
-	return true;
+	{
+		SetData(NULL);
+		return;
+	}
+	auto din = dynamic_cast<AnalogWaveform*>(m_channels[0]->GetData());
+	if(din == NULL)
+	{
+		SetData(NULL);
+		return;
+	}
+
+	//We need meaningful data
+	size_t len = din->m_samples.size();
+	if(len == 0)
+	{
+		SetData(NULL);
+		return;
+	}
+
+	//Figure out the nominal midpoint of the waveform
+	float top = Measurement::GetTopVoltage(din);
+	float base = Measurement::GetBaseVoltage(din);
+	float midpoint = (top+base)/2;
+
+	//Create the output
+	auto cap = new AnalogWaveform;
+
+	float 		fmax = -FLT_MAX;
+	float		fmin =  FLT_MAX;
+
+	int64_t		tmin		= 0;
+	float		vmin		= FLT_MAX;
+	float		vmax		= -FLT_MAX;
+	float		last_max	= -FLT_MAX;
+
+	//For each cycle, find the min and max
+	bool		last_was_low	= true;
+	for(size_t i=0; i < len; i++)
+	{
+		//If we're above the midpoint, reset everything and add a new sample
+		float v = din->m_samples[i];
+		if(v > midpoint)
+		{
+			last_was_low = false;
+
+			//Add a sample for the current value (if any)
+			if( (tmin > 0) && (last_max > -FLT_MAX/2) )
+			{
+				//Update duration of the previous sample
+				size_t off = cap->m_offsets.size();
+				if(off > 0)
+					cap->m_durations[off-1] = tmin - cap->m_offsets[off-1];
+
+				float value = last_max - vmin;
+
+				fmax = max(fmax, value);
+				fmin = min(fmin, value);
+
+				//Add the new sample
+				cap->m_offsets.push_back(tmin);
+				cap->m_durations.push_back(0);
+				cap->m_samples.push_back(value);
+			}
+
+			//Reset
+			tmin = 0;
+			vmin = FLT_MAX;
+
+			//Accumulate
+			vmax = max(vmax, v);
+		}
+
+		//Accumulate the lowest peak of this cycle
+		//and save the
+		else
+		{
+			if(!last_was_low)
+			{
+				last_max = vmax;
+				vmax = -FLT_MAX;
+				last_was_low = true;
+			}
+
+			if(v < vmin)
+			{
+				tmin = din->m_offsets[i];
+				vmin = v;
+			}
+		}
+	}
+
+	m_range = fmax - fmin;
+	if(m_range < 0.025)
+		m_range = 0.025;
+	m_midpoint = (fmax + fmin) / 2;
+
+	SetData(cap);
+
+	//Copy start time etc from the input.
+	cap->m_timescale = din->m_timescale;
+	cap->m_startTimestamp = din->m_startTimestamp;
+	cap->m_startPicoseconds = din->m_startPicoseconds;
 }
diff --git a/scopemeasurements/PkPkVoltageMeasurement.h → scopeprotocols/PkPkMeasurementDecoder.h b/scopemeasurements/PkPkVoltageMeasurement.h → scopeprotocols/PkPkMeasurementDecoder.h
@@ -2,7 +2,7 @@
 *                                                                                                                      *
 * ANTIKERNEL v0.1                                                                                                      *
 *                                                                                                                      *
-* Copyright (c) 2012-2019 Andrew D. Zonenberg                                                                          *
+* Copyright (c) 2012-2020 Andrew D. Zonenberg                                                                          *
 * All rights reserved.                                                                                                 *
 *                                                                                                                      *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the     *
@@ -30,27 +30,36 @@
 /**
 	@file
 	@author Andrew D. Zonenberg
-	@brief Declaration of PkPkVoltageMeasurement
+	@brief Declaration of PkPkMeasurementDecoder
  */
-#ifndef PkPkVoltageMeasurement_h
-#define PkPkVoltageMeasurement_h
+#ifndef PkPkMeasurementDecoder_h
+#define PkPkMeasurementDecoder_h
 
-#include "../scopehal/Measurement.h"
+#include "../scopehal/ProtocolDecoder.h"
 
-class PkPkVoltageMeasurement : public FloatMeasurement
+class PkPkMeasurementDecoder : public ProtocolDecoder
 {
 public:
-	PkPkVoltageMeasurement();
-	virtual ~PkPkVoltageMeasurement();
+	PkPkMeasurementDecoder(std::string color);
 
-	virtual bool Refresh();
+	virtual void Refresh();
+
+	virtual bool NeedsConfig();
+	virtual bool IsOverlay();
+
+	static std::string GetProtocolName();
+	virtual void SetDefaultName();
+
+	virtual double GetVoltageRange();
+	virtual double GetOffset();
 
-	static std::string GetMeasurementName();
 	virtual bool ValidateChannel(size_t i, OscilloscopeChannel* channel);
 
-	virtual MeasurementType GetMeasurementType();
+	PROTOCOL_DECODER_INITPROC(PkPkMeasurementDecoder)
 
-	MEASUREMENT_INITPROC(PkPkVoltageMeasurement)
+protected:
+	double m_midpoint;
+	double m_range;
 };
 
 #endif
diff --git a/scopeprotocols/TopMeasurementDecoder.cpp b/scopeprotocols/TopMeasurementDecoder.cpp
@@ -159,7 +159,7 @@ void TopMeasurementDecoder::Refresh()
 
 	for(size_t i=0; i < len; i++)
 	{
-		//Wait for a falling edge
+		//Wait for a rising edge
 		float cur = din->m_samples[i];
 		int64_t tnow = din->m_offsets[i] * din->m_timescale;
 

diff --git a/scopemeasurements/UndershootMeasurement.cpp → ...rotocols/UndershootMeasurementDecoder.cpp b/scopemeasurements/UndershootMeasurement.cpp → ...rotocols/UndershootMeasurementDecoder.cpp
@@ -2,7 +2,7 @@
 *                                                                                                                      *
 * ANTIKERNEL v0.1                                                                                                      *
 *                                                                                                                      *
-* Copyright (c) 2012-2019 Andrew D. Zonenberg                                                                          *
+* Copyright (c) 2012-2020 Andrew D. Zonenberg                                                                          *
 * All rights reserved.                                                                                                 *
 *                                                                                                                      *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the     *
@@ -27,68 +27,163 @@
 *                                                                                                                      *
 ***********************************************************************************************************************/
 
-/**
-	@file
-	@author Andrew D. Zonenberg
-	@brief Declaration of UndershootMeasurement
- */
-
-#include "scopemeasurements.h"
-#include "UndershootMeasurement.h"
+#include "scopeprotocols.h"
+#include "UndershootMeasurementDecoder.h"
 
 using namespace std;
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-// Construction/destruction
+// Construction / destruction
 
-UndershootMeasurement::UndershootMeasurement()
-	: FloatMeasurement(TYPE_PERCENTAGE)
+UndershootMeasurementDecoder::UndershootMeasurementDecoder(string color)
+	: ProtocolDecoder(OscilloscopeChannel::CHANNEL_TYPE_ANALOG, color, CAT_MEASUREMENT)
 {
-	//Configure for a single input
-	m_signalNames.push_back("Vin");
+	//Set up channels
+	m_signalNames.push_back("din");
 	m_channels.push_back(NULL);
+
+	m_midpoint = 0;
+	m_range = 1;
 }
 
-UndershootMeasurement::~UndershootMeasurement()
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Factory methods
+
+bool UndershootMeasurementDecoder::ValidateChannel(size_t i, OscilloscopeChannel* channel)
 {
+	if( (i == 0) && (channel->GetType() == OscilloscopeChannel::CHANNEL_TYPE_ANALOG) )
+		return true;
+	return false;
 }
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // Accessors
 
-Measurement::MeasurementType UndershootMeasurement::GetMeasurementType()
+void UndershootMeasurementDecoder::SetDefaultName()
 {
-	return Measurement::MEAS_VERT;
+	char hwname[256];
+	snprintf(hwname, sizeof(hwname), "Undershoot(%s)", m_channels[0]->m_displayname.c_str());
+	m_hwname = hwname;
+	m_displayname = m_hwname;
 }
 
-string UndershootMeasurement::GetMeasurementName()
+string UndershootMeasurementDecoder::GetProtocolName()
 {
 	return "Undershoot";
 }
 
-bool UndershootMeasurement::ValidateChannel(size_t i, OscilloscopeChannel* channel)
+bool UndershootMeasurementDecoder::IsOverlay()
 {
-	if( (i == 0) && (channel->GetType() == OscilloscopeChannel::CHANNEL_TYPE_ANALOG) )
-		return true;
+	//we create a new analog channel
+	return false;
+}
+
+bool UndershootMeasurementDecoder::NeedsConfig()
+{
+	//automatic configuration
 	return false;
 }
 
+double UndershootMeasurementDecoder::GetVoltageRange()
+{
+	return m_range;
+}
+
+double UndershootMeasurementDecoder::GetOffset()
+{
+	return -m_midpoint;
+}
+
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-// Measurement processing
+// Actual decoder logic
 
-bool UndershootMeasurement::Refresh()
+void UndershootMeasurementDecoder::Refresh()
 {
 	//Get the input data
 	if(m_channels[0] == NULL)
-		return false;
-	AnalogCapture* din = dynamic_cast<AnalogCapture*>(m_channels[0]->GetData());
-	if(din == NULL || (din->GetDepth() == 0))
-		return false;
-
-	//Calculate the worst case undershoot
-	float min = GetMinVoltage(din);
-	float top = GetTopVoltage(din);
-	float base = GetBaseVoltage(din);
-	m_value = (base-min) / (top-base);
-	return true;
+	{
+		SetData(NULL);
+		return;
+	}
+	auto din = dynamic_cast<AnalogWaveform*>(m_channels[0]->GetData());
+	if(din == NULL)
+	{
+		SetData(NULL);
+		return;
+	}
+
+	//We need meaningful data
+	size_t len = din->m_samples.size();
+	if(len == 0)
+	{
+		SetData(NULL);
+		return;
+	}
+
+	//Figure out the nominal top of the waveform
+	float top = Measurement::GetTopVoltage(din);
+	float base = Measurement::GetBaseVoltage(din);
+	float midpoint = (top+base)/2;
+
+	//Create the output
+	auto cap = new AnalogWaveform;
+
+	float 		fmax = -FLT_MAX;
+	float		fmin =  FLT_MAX;
+
+	int64_t		tmin = 0;
+	float		vmin = FLT_MAX;
+
+	//For each cycle, find how far we got below the base
+	for(size_t i=0; i < len; i++)
+	{
+		//If we're above the midpoint, reset everything and add a new sample
+		float v = din->m_samples[i];
+		if(v > midpoint)
+		{
+			//Add a sample for the current value (if any)
+			if(tmin > 0)
+			{
+				//Update duration of the previous sample
+				size_t off = cap->m_offsets.size();
+				if(off > 0)
+					cap->m_durations[off-1] = tmin - cap->m_offsets[off-1];
+
+				float value = base - vmin;
+				fmax = max(fmax, value);
+				fmin = min(fmin, value);
+
+				//Add the new sample
+				cap->m_offsets.push_back(tmin);
+				cap->m_durations.push_back(0);
+				cap->m_samples.push_back(value);
+			}
+
+			//Reset
+			tmin = 0;
+			vmin = FLT_MAX;
+		}
+
+		//Accumulate the lowest peak of this cycle
+		else
+		{
+			if(v < vmin)
+			{
+				tmin = din->m_offsets[i];
+				vmin = v;
+			}
+		}
+	}
+
+	m_range = fmax - fmin;
+	if(m_range < 0.025)
+		m_range = 0.025;
+	m_midpoint = (fmax + fmin) / 2;
+
+	SetData(cap);
+
+	//Copy start time etc from the input.
+	cap->m_timescale = din->m_timescale;
+	cap->m_startTimestamp = din->m_startTimestamp;
+	cap->m_startPicoseconds = din->m_startPicoseconds;
 }
diff --git a/scopemeasurements/OvershootMeasurement.h → ...eprotocols/UndershootMeasurementDecoder.h b/scopemeasurements/OvershootMeasurement.h → ...eprotocols/UndershootMeasurementDecoder.h
@@ -2,7 +2,7 @@
 *                                                                                                                      *
 * ANTIKERNEL v0.1                                                                                                      *
 *                                                                                                                      *
-* Copyright (c) 2012-2019 Andrew D. Zonenberg                                                                          *
+* Copyright (c) 2012-2020 Andrew D. Zonenberg                                                                          *
 * All rights reserved.                                                                                                 *
 *                                                                                                                      *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the     *
@@ -30,27 +30,36 @@
 /**
 	@file
 	@author Andrew D. Zonenberg
-	@brief Declaration of OvershootMeasurement
+	@brief Declaration of UndershootMeasurementDecoder
  */
-#ifndef OvershootMeasurement_h
-#define OvershootMeasurement_h
+#ifndef UndershootMeasurementDecoder_h
+#define UndershootMeasurementDecoder_h
 
-#include "../scopehal/Measurement.h"
+#include "../scopehal/ProtocolDecoder.h"
 
-class OvershootMeasurement : public FloatMeasurement
+class UndershootMeasurementDecoder : public ProtocolDecoder
 {
 public:
-	OvershootMeasurement();
-	virtual ~OvershootMeasurement();
+	UndershootMeasurementDecoder(std::string color);
 
-	virtual bool Refresh();
+	virtual void Refresh();
+
+	virtual bool NeedsConfig();
+	virtual bool IsOverlay();
+
+	static std::string GetProtocolName();
+	virtual void SetDefaultName();
+
+	virtual double GetVoltageRange();
+	virtual double GetOffset();
 
-	static std::string GetMeasurementName();
 	virtual bool ValidateChannel(size_t i, OscilloscopeChannel* channel);
 
-	virtual MeasurementType GetMeasurementType();
+	PROTOCOL_DECODER_INITPROC(UndershootMeasurementDecoder)
 
-	MEASUREMENT_INITPROC(OvershootMeasurement)
+protected:
+	double m_midpoint;
+	double m_range;
 };
 
 #endif
diff --git a/scopeprotocols/scopeprotocols.cpp b/scopeprotocols/scopeprotocols.cpp
@@ -71,7 +71,9 @@ void ScopeProtocolStaticInit()
 	AddDecoderClass(JtagDecoder);
 	AddDecoderClass(MDIODecoder);
 	AddDecoderClass(MovingAverageDecoder);
+	AddDecoderClass(OvershootMeasurementDecoder);
 	AddDecoderClass(ParallelBusDecoder);
+	AddDecoderClass(PkPkMeasurementDecoder);
 	AddDecoderClass(PeriodMeasurementDecoder);
 	AddDecoderClass(RiseMeasurementDecoder);
 	AddDecoderClass(SincInterpolationDecoder);
@@ -81,6 +83,7 @@ void ScopeProtocolStaticInit()
 	AddDecoderClass(TopMeasurementDecoder);
 	AddDecoderClass(UARTDecoder);
 	AddDecoderClass(UartClockRecoveryDecoder);
+	AddDecoderClass(UndershootMeasurementDecoder);
 	AddDecoderClass(USB2ActivityDecoder);
 	AddDecoderClass(USB2PacketDecoder);
 	AddDecoderClass(USB2PCSDecoder);

diff --git a/scopeprotocols/scopeprotocols.h b/scopeprotocols/scopeprotocols.h
@@ -72,7 +72,9 @@
 #include "JtagDecoder.h"
 #include "MDIODecoder.h"
 #include "MovingAverageDecoder.h"
+#include "OvershootMeasurementDecoder.h"
 #include "ParallelBusDecoder.h"
+#include "PkPkMeasurementDecoder.h"
 #include "PeriodMeasurementDecoder.h"
 #include "RiseMeasurementDecoder.h"
 #include "SincInterpolationDecoder.h"
@@ -82,6 +84,7 @@
 #include "TopMeasurementDecoder.h"
 #include "UARTDecoder.h"
 #include "UartClockRecoveryDecoder.h"
+#include "UndershootMeasurementDecoder.h"
 #include "USB2ActivityDecoder.h"
 #include "USB2PacketDecoder.h"
 #include "USB2PCSDecoder.h"