From c33d644fb0382662474979ddf78969b80e3e4bd2 Mon Sep 17 00:00:00 2001
From: robtor <robtor2000@web.de>
Date: Wed, 18 Jun 2025 13:51:40 +0200
Subject: [PATCH] simple crude fir filter

---
 Tests/CMakeLists.txt                   | 19 ++++++++++++++++
 Tests/modules.cpp                      | 18 ++++++++++++++++
 floatpump/Modules/filter_fir_crude.cpp | 30 ++++++++++++++++++++++++++
 floatpump/Modules/filter_fir_crude.h   | 19 ++++++++++++++++
 4 files changed, 86 insertions(+)
 create mode 100644 Tests/modules.cpp
 create mode 100644 floatpump/Modules/filter_fir_crude.cpp
 create mode 100644 floatpump/Modules/filter_fir_crude.h

diff --git a/Tests/CMakeLists.txt b/Tests/CMakeLists.txt
index 534e69c..ec367d0 100644
--- a/Tests/CMakeLists.txt
+++ b/Tests/CMakeLists.txt
@@ -3,6 +3,25 @@
 add_executable(testtests experiments/example-test.cpp)
 target_link_libraries(testtests PRIVATE Catch2::Catch2WithMain)
 
+
+# Firmware modules tests
+file(GLOB_RECURSE FWMODULES_SOURCES
+        "${CMAKE_SOURCE_DIR}/floatpump/Modules/*.cpp"
+)
+
+add_executable(fwmodules
+    ${FWMODULES_SOURCES}
+    modules.cpp
+)
+
+
+
+target_include_directories(fwmodules PUBLIC
+        ${CMAKE_SOURCE_DIR}/floatpump/Modules
+)
+
+target_link_libraries(fwmodules PRIVATE Catch2::Catch2WithMain)
+
 # General catch configuration
 include(CTest)
 include(Catch)
diff --git a/Tests/modules.cpp b/Tests/modules.cpp
new file mode 100644
index 0000000..42e971e
--- /dev/null
+++ b/Tests/modules.cpp
@@ -0,0 +1,18 @@
+#include <catch2/catch_test_macros.hpp>
+
+#include "filter_fir_crude.h"
+
+TEST_CASE("Filter Modules", "[filter]")
+{
+    SECTION("FIR Filter Crude Implementation")
+    {
+        float coeffs[] = {1,1,1};
+        FilterFIRCrude filter1(coeffs, 3);
+
+        filter1.process(10);
+        filter1.process(10);
+        auto res = filter1.process(10);
+
+        REQUIRE(res == 10);
+    }
+}
\ No newline at end of file
diff --git a/floatpump/Modules/filter_fir_crude.cpp b/floatpump/Modules/filter_fir_crude.cpp
new file mode 100644
index 0000000..6017e87
--- /dev/null
+++ b/floatpump/Modules/filter_fir_crude.cpp
@@ -0,0 +1,30 @@
+#include "filter_fir_crude.h"
+
+FilterFIRCrude::FilterFIRCrude(const float* coeffs, size_t numTaps) :
+_coeffs(coeffs), _histsize(numTaps), _index(0)
+{
+    _history = new float[_histsize];
+    std::memset(_history, 0 , numTaps*sizeof(float));
+}
+
+float FilterFIRCrude::process(float input)
+{
+    _history[_index] = input;
+
+    float result = 0.0f;
+    size_t idx = _index;
+    for (size_t i = 0; i < _histsize; ++i)
+    {
+        result += _coeffs[i] * _history[idx];
+        if (idx == 0)
+        {
+            idx = _histsize - 1;
+        } else
+        {
+            --idx;
+        }
+        _index = (_index + 1) % _histsize;
+    }
+    return result;
+}
+
diff --git a/floatpump/Modules/filter_fir_crude.h b/floatpump/Modules/filter_fir_crude.h
new file mode 100644
index 0000000..d127dc1
--- /dev/null
+++ b/floatpump/Modules/filter_fir_crude.h
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <cstdint>
+#include <cstring>
+#include <cstddef>
+
+class FilterFIRCrude
+{
+public:
+    FilterFIRCrude(const float* coeffs, size_t numTaps);
+    float process(float input);
+
+private:
+    const float* _coeffs;
+    size_t _histsize;
+    float* _history;
+    size_t _index;
+};
+