I2C protocol analyzer

Software/LogicAnalyzer/I2CProtocolAnalyzer/I2CAnalyzer.cs

@@ -0,0 +1,275 @@
+using Avalonia.Input.TextInput;
+using Avalonia.Media;
+using LogicAnalyzer.Protocols;
+using Newtonsoft.Json.Linq;
+using System.Data;
+using System.Text;
+
+namespace I2CProtocolAnalyzer
+{
+    public class I2CAnalyzer : ProtocolAnalyzerBase
+    {
+        private SimpleSegmentRenderer renderer = new SimpleSegmentRenderer();
+
+        public override string ProtocolName
+        {
+            get
+            {
+                return "I2C";
+            }
+        }
+
+        public override ProtocolAnalyzerSetting[] Settings
+        {
+            get
+            {
+                return new ProtocolAnalyzerSetting[0];
+            }
+        }
+
+        public override ProtocolAnalyzerSignal[] Signals
+        {
+            get
+            {
+                return new ProtocolAnalyzerSignal[] 
+                {
+                    new ProtocolAnalyzerSignal{ Required = true, SignalName = "SCL" },
+                    new ProtocolAnalyzerSignal{ Required = true, SignalName = "SDA" },
+                };
+            }
+        }
+
+        public override ProtocolAnalyzedChannel[] Analyze(int SamplingRate, int TriggerSample, ProtocolAnalyzerSettingValue[] SelectedSettings, ProtocolAnalyzerSelectedChannel[] SelectedChannels)
+        {
+            var scl = SelectedChannels.Where(c => c.SignalName == "SCL").First();
+            var sda = SelectedChannels.Where(c => c.SignalName == "SDA").First();
+
+            List<ProtocolAnalyzerDataSegment> segments = new List<ProtocolAnalyzerDataSegment>();
+
+            int startPosition;
+            int endPosition;
+            byte value;
+            bool ack;
+            bool frameError;
+            bool foundStartStop;
+
+            bool addressByte = true;
+            bool address10 = false;
+            byte firstAddressByte = 0;
+
+            int pos = FindStartCondition(0, scl, sda, out startPosition, out endPosition);
+
+            if (pos == -1)
+                return new ProtocolAnalyzedChannel[0];
+
+            segments.Add(new ProtocolAnalyzerDataSegment { FirstSample = startPosition, LastSample = endPosition, Value = $"START" });
+
+            while (pos < sda.Samples.Length)
+            {
+                pos = ReadByte(pos, scl, sda, out startPosition, out endPosition, out value, out ack, out frameError);
+
+                if (pos == -1)
+                    break;
+
+                string asciival = value >= 0x20 && value <= 0x7e ? Encoding.ASCII.GetString(new byte[] { (byte)value }) : "·";
+
+                var segment = new ProtocolAnalyzerDataSegment { FirstSample = startPosition, LastSample = endPosition, Value = $"0x{value.ToString()} '{asciival}' <{(ack ? "A" : "N")}{(frameError ? "F" : "")}>" };
+
+                if (addressByte)
+                {
+                    addressByte = false;
+
+                    segment.Value += $"\r\nOp: {((value & 1) == 1 ? "Read" : "Write") }";
+
+                    if ((value & 0xf8) == 0xf7)
+                    {
+                        address10 = true;
+                        firstAddressByte = value;
+                    }
+                    else
+                        segment.Value += $"\r\nAddress (7b): 0x{(value >> 1).ToString("X2")}";
+                    
+                }
+                else if (address10)
+                {
+                    address10 = false;
+                    segment.Value += $"\r\nAddress (10b): {(((firstAddressByte & 6) << 7) | value).ToString("X4")}";
+                }
+
+                segments.Add(segment);
+
+                bool isStart;
+
+                pos = FindStartStopCondition(pos, scl, sda, out isStart, out startPosition, out endPosition, out foundStartStop);
+
+                if (pos == -1)
+                    break;
+
+                if(foundStartStop)
+                    segments.Add(new ProtocolAnalyzerDataSegment { FirstSample = startPosition, LastSample = endPosition, Value = isStart ? "START" : "STOP" });
+
+                if (foundStartStop && !isStart)
+                {
+                    pos = FindStartCondition(pos, scl, sda, out startPosition, out endPosition);
+
+                    if (pos == -1)
+                        break;
+
+                    segments.Add(new ProtocolAnalyzerDataSegment { FirstSample = startPosition, LastSample = endPosition, Value = $"START" });
+
+                    addressByte = true;
+                }
+            }
+
+            ProtocolAnalyzedChannel channel = new ProtocolAnalyzedChannel("SDA", sda.ChannelIndex, renderer, segments.ToArray(), Colors.White, Color.FromUInt32(0x7f008b8b));
+
+            return new ProtocolAnalyzedChannel[] { channel };
+        }
+
+        private int FindStartStopCondition(int pos, ProtocolAnalyzerSelectedChannel scl, ProtocolAnalyzerSelectedChannel sda, out bool isStart, out int startPosition, out int endPosition, out bool found)
+        {
+            int initialPosition = pos;
+            isStart = false;
+            startPosition = 0;
+            endPosition = 0;
+            found = false;
+
+            while (pos < scl.Samples.Length && scl.Samples[pos] != 1)
+                pos++;
+
+            if (pos >= scl.Samples.Length)
+                return -1;
+
+            startPosition = pos;
+
+            byte val = sda.Samples[pos];
+            //Initial state will indicate if this may be an start or an stop
+            isStart = val == 1;
+
+            while (pos < scl.Samples.Length && scl.Samples[pos] == 1)
+            {
+                if (val != sda.Samples[pos])
+                {
+                    found = true;
+                    break;
+                }
+                pos++;
+            }
+
+            if (pos >= scl.Samples.Length)
+                return -1;
+
+            if (!found)
+                return initialPosition;
+
+            endPosition = pos - 1;
+
+            return pos;
+        }
+
+        private int FindStartCondition(int pos, ProtocolAnalyzerSelectedChannel scl, ProtocolAnalyzerSelectedChannel sda, out int startPosition, out int endPosition)
+        {
+            startPosition = 0; endPosition = 0;
+
+            while (pos < scl.Samples.Length)
+            {
+                while (pos < scl.Samples.Length && scl.Samples[pos] != 1)
+                    pos++;
+
+                if (pos >= scl.Samples.Length)
+                    return -1;
+
+                startPosition = pos;
+                bool foundStart = false;
+
+                if (scl.Samples[pos] != 1) //SDA is low, it cannot be a start
+                {
+                    while (pos < scl.Samples.Length && scl.Samples[pos] == 1)
+                        pos++;
+
+                    if (pos >= scl.Samples.Length)
+                        return -1;
+                }
+                else
+                {
+                    while (pos < scl.Samples.Length && scl.Samples[pos] == 1)
+                    {
+                        if (sda.Samples[pos] != 1)
+                        {
+                            foundStart = true;
+                            break;
+                        }
+
+                        pos++;
+                    }
+                }
+
+                if (foundStart)
+                {
+                    endPosition = pos - 1;
+                    return pos;
+                }
+            }
+
+            return -1;
+        }
+
+        private int ReadByte(int pos, ProtocolAnalyzerSelectedChannel scl, ProtocolAnalyzerSelectedChannel sda, out int byteStart, out int byteEnd, out byte value, out bool ack, out bool frameError)
+        {
+            byteStart = 0; byteEnd = 0; value = 0; ack = false; frameError= false;
+
+            while (pos < scl.Samples.Length && scl.Samples[pos] == 1) //Find next low clock
+                pos++;
+
+            if (pos >= scl.Samples.Length) //
+                return -1;
+
+            byteStart = pos;
+
+            for (int buc = 0; buc < 9; buc++)
+            {
+                while (pos < scl.Samples.Length && scl.Samples[pos] == 1) //Find next low clock
+                    pos++;
+
+                while (pos < scl.Samples.Length && scl.Samples[pos] == 0) //Find high clock
+                    pos++;
+
+                if (pos >= scl.Samples.Length) //
+                    return -1;
+
+                byte sampleValue = sda.Samples[pos];
+
+                if (buc < 8)
+                {
+                    value |= (byte)(sampleValue << (7 - buc)); //Get the value
+
+                }
+                else
+                    ack = sampleValue == 0; //Get the ACK/NACK
+
+                //Check for frame errors, any change of SDA while SCL is high and is in the middle
+                //of a byte is a frame error, SDA can change only while the bus is idle or at the end of a byte
+                //indicating a start or a stop
+                while (pos < scl.Samples.Length && scl.Samples[pos] == 1)
+                {
+                    if (sda.Samples[pos] != sampleValue)
+                        frameError = true;
+
+                    pos++;
+                }
+            }
+
+            byteEnd = pos - 1;
+
+            return pos;
+        }
+
+        public override bool ValidateSettings(ProtocolAnalyzerSettingValue[] SelectedSettings, ProtocolAnalyzerSelectedChannel[] SelectedChannels)
+        {
+            if (SelectedChannels == null || SelectedChannels.Length != 2)
+                return false;
+
+            return true;
+        }
+    }
+}

Software/LogicAnalyzer/I2CProtocolAnalyzer/I2CProtocolAnalyzer.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\LogicAnalyzer\LogicAnalyzer.csproj" />
+  </ItemGroup>
+
+</Project>

Software/LogicAnalyzer/LogicAnalyzer.sln

@@ -11,7 +11,9 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "LogicAnalyzer", "LogicAnaly
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SPIProtocolAnalyzer", "SPIProtocolAnalyzer\SPIProtocolAnalyzer.csproj", "{6F18CFDA-7596-47F7-ABB9-AB09DC003C0B}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SerialProtocolAnalyzer", "SerialProtocolAnalyzer\SerialProtocolAnalyzer.csproj", "{E71855EA-04A7-48C1-860A-6A85E9D9E727}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SerialProtocolAnalyzer", "SerialProtocolAnalyzer\SerialProtocolAnalyzer.csproj", "{E71855EA-04A7-48C1-860A-6A85E9D9E727}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "I2CProtocolAnalyzer", "I2CProtocolAnalyzer\I2CProtocolAnalyzer.csproj", "{74E41F50-E208-4690-84C6-51012C2F26E2}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -39,6 +41,10 @@ Global
 		{E71855EA-04A7-48C1-860A-6A85E9D9E727}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{E71855EA-04A7-48C1-860A-6A85E9D9E727}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{E71855EA-04A7-48C1-860A-6A85E9D9E727}.Release|Any CPU.Build.0 = Release|Any CPU
+		{74E41F50-E208-4690-84C6-51012C2F26E2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{74E41F50-E208-4690-84C6-51012C2F26E2}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{74E41F50-E208-4690-84C6-51012C2F26E2}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{74E41F50-E208-4690-84C6-51012C2F26E2}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

Software/LogicAnalyzer/SPIProtocolAnalyzer/SPIAnalyzer.cs

@@ -166,7 +166,7 @@ namespace SPIProtocolAnalyzer
 
                         string asciival = value >= 0x20 && value <= 0x7e ? Encoding.ASCII.GetString(new byte[] { (byte)value }) : "·";
 
-                        ProtocolAnalyzerDataSegment segment = new ProtocolAnalyzerDataSegment { FirstSample = range.FirstSample + firstClockSample, LastSample = range.FirstSample + lastSample, Value = $"0x{value.ToString("X2")} (\"{asciival}\")" };
+                        ProtocolAnalyzerDataSegment segment = new ProtocolAnalyzerDataSegment { FirstSample = range.FirstSample + firstClockSample, LastSample = range.FirstSample + lastSample, Value = $"0x{value.ToString("X2")} '{asciival}'" };
                         segments.Add(segment);
 
                         firstClockSample = FindSample(lastSample, clockRange, cpha == 0 ? 1 : 0);

Software/LogicAnalyzer/SerialProtocolAnalyzer/SerialAnalyzer.cs

@@ -171,8 +171,10 @@ namespace SerialProtocolAnalyzer
 
                 int endPos = (int)Math.Round(samplePos, 0);
 
+                string asciival = value >= 0x20 && value <= 0x7e ? Encoding.ASCII.GetString(new byte[] { (byte)value }) : "·";
+
                 ProtocolAnalyzerDataSegment newSegment = new ProtocolAnalyzerDataSegment();
-                newSegment.Value = "0x" + value.ToString("X2") + "-'" + Encoding.ASCII.GetString(new byte[] { value }) + "'";
+                newSegment.Value = $"0x{value.ToString("X2")} '{asciival}'";
                 newSegment.FirstSample = startPos;
                 newSegment.LastSample = endPos;
                 string errors = "";