diff --git a/pid/ec/stepwise.cpp b/pid/ec/stepwise.cpp
new file mode 100644
index 0000000..4246fb3
--- /dev/null
+++ b/pid/ec/stepwise.cpp
@@ -0,0 +1,45 @@
+/*
+// Copyright (c) 2018 Intel Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+*/
+
+#include "stepwise.hpp"
+
+#include <cstddef>
+#include <limits>
+
+namespace ec
+{
+float stepwise(const ec::StepwiseInfo& info, float input)
+{
+    float value = info.output[0]; // if we are below the lowest
+                                  // point, we set the lowest value
+
+    for (size_t ii = 1; ii < ec::maxStepwisePoints; ii++)
+    {
+
+        if (info.reading[ii] == std::numeric_limits<float>::quiet_NaN())
+        {
+            break;
+        }
+        if (info.reading[ii] > input)
+        {
+            break;
+        }
+        value = info.output[ii];
+    }
+
+    return value;
+}
+} // namespace ec
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diff --git a/pid/ec/stepwise.hpp b/pid/ec/stepwise.hpp
new file mode 100644
index 0000000..ed07b44
--- /dev/null
+++ b/pid/ec/stepwise.hpp
@@ -0,0 +1,36 @@
+
+/*
+// Copyright (c) 2018 Intel Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+*/
+
+#pragma once
+
+#include <cstddef>
+#include <vector>
+
+namespace ec
+{
+constexpr size_t maxStepwisePoints = 20;
+
+struct StepwiseInfo
+{
+    float ts; // sample time in seconds
+    float reading[maxStepwisePoints];
+    float output[maxStepwisePoints];
+};
+
+float stepwise(const ec::StepwiseInfo& info, float value);
+
+} // namespace ec
\ No newline at end of file