Update Installation Guide: Add ESP-IDF Support Policy, Optimize PlatformIO Configuration, and Fix Missing array.h Compilation Issue (TFMIC-47)

README.md

@@ -18,6 +18,8 @@ We keep track with the ESP-IDF's support period policy mentioned [here](https://
 
 Currently ESP-IDF versions `release/v4.4` and above are supported by this project.
 
+## Method 1: Using ESP IDF
+
 ### Install the ESP IDF
 
 Follow the instructions of the
@@ -29,6 +31,28 @@ The next steps assume that this installation is successful and the
 * the `IDF_PATH` environment variable is set
 * the `idf.py` and Xtensa-esp32 tools (e.g., `xtensa-esp32-elf-gcc`) are in `$PATH`
 
+## Method 2: Using PlatformIO
+
+### Configuration
+
+Add the following configuration to your `platformio.ini` file:
+
+```ini
+[env:your_env_name]
+build_flags =
+    -I ${PROJECT_LIBDEPS_DIR}/${PIOENV}/esp-tflite-micro/third_party/flatbuffers/include
+    -I ${PROJECT_LIBDEPS_DIR}/${PIOENV}/esp-tflite-micro/third_party/gemmlowp
+    -I ${PROJECT_LIBDEPS_DIR}/${PIOENV}/esp-tflite-micro/third_party/kissfft
+    -I ${PROJECT_LIBDEPS_DIR}/${PIOENV}/esp-tflite-micro/third_party/ruy
+    -Ofast
+
+lib_deps = 
+    https://github.com/espressif/esp-tflite-micro.git
+
+; src_dir = 
+    -I ${PROJECT_LIBDEPS_DIR}/${PIOENV}/esp-tflite-micro/examples/hello_world
+```
+
 ## Using the component
 
 Run the following command in your ESP-IDF project to install this component:

tensorflow/lite/array.h

@@ -0,0 +1,123 @@
+/* Copyright 2023 The TensorFlow Authors. All Rights Reserved.
+
+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.
+==============================================================================*/
+#ifndef TENSORFLOW_LITE_ARRAY_H_
+#define TENSORFLOW_LITE_ARRAY_H_
+
+#include <cstring>
+#include <initializer_list>
+#include <memory>
+#include <type_traits>
+#include <vector>
+
+#include "tensorflow/lite/core/c/common.h"
+
+namespace tflite {
+
+/// TfLite*Array helpers
+
+namespace array_internal {
+
+// Function object used as a deleter for unique_ptr holding TFLite*Array
+// objects.
+struct TfLiteArrayDeleter {
+  void operator()(TfLiteIntArray* a);
+  void operator()(TfLiteFloatArray* a);
+};
+
+// Maps T to the corresponding TfLiteArray type.
+template <class T>
+struct TfLiteArrayInfo;
+
+template <>
+struct TfLiteArrayInfo<int> {
+  using Type = TfLiteIntArray;
+};
+
+template <>
+struct TfLiteArrayInfo<float> {
+  using Type = TfLiteFloatArray;
+};
+
+}  // namespace array_internal
+
+template <class T>
+using TfLiteArrayUniquePtr =
+    std::unique_ptr<typename array_internal::TfLiteArrayInfo<T>::Type,
+                    array_internal::TfLiteArrayDeleter>;
+
+// `unique_ptr` wrapper for `TfLiteIntArray`s.
+using IntArrayUniquePtr = TfLiteArrayUniquePtr<int>;
+
+// `unique_ptr` wrapper for `TfLiteFloatArray`s.
+using FloatArrayUniquePtr = TfLiteArrayUniquePtr<float>;
+
+// Allocates a TfLiteArray of given size using malloc.
+//
+// This builds an int array by default as this is the overwhelming part of the
+// use cases.
+template <class T = int>
+TfLiteArrayUniquePtr<T> BuildTfLiteArray(int size);
+
+// Allocates a TfLiteIntArray of given size using malloc.
+template <>
+inline IntArrayUniquePtr BuildTfLiteArray<int>(const int size) {
+  return IntArrayUniquePtr(TfLiteIntArrayCreate(size));
+}
+
+// Allocates a TfLiteFloatArray of given size using malloc.
+template <>
+inline FloatArrayUniquePtr BuildTfLiteArray<float>(const int size) {
+  return FloatArrayUniquePtr(TfLiteFloatArrayCreate(size));
+}
+
+// Allocates a TFLiteArray of given size and initializes it.
+//
+// `values` is expected to holds `size` elements.
+template <class T>
+TfLiteArrayUniquePtr<T> BuildTfLiteArray(const int size,
+                                         const T* const values) {
+  auto array = BuildTfLiteArray<T>(size);
+  if (array) {
+    memcpy(array->data, values, size * sizeof(T));
+  }
+  return array;
+}
+
+// Allocates a TFLiteArray and initializes it with the given values.
+template <class T>
+TfLiteArrayUniquePtr<T> BuildTfLiteArray(const std::vector<T>& values) {
+  return BuildTfLiteArray(static_cast<int>(values.size()), values.data());
+}
+
+// Allocates a TFLiteArray and initializes it with the given values.
+template <class T>
+TfLiteArrayUniquePtr<T> BuildTfLiteArray(
+    const std::initializer_list<T>& values) {
+  return BuildTfLiteArray(static_cast<int>(values.size()), values.begin());
+}
+
+// Allocates a TFLiteArray and initializes it with the given array.
+inline IntArrayUniquePtr BuildTfLiteArray(const TfLiteIntArray& other) {
+  return BuildTfLiteArray(other.size, other.data);
+}
+
+// Allocates a TFLiteArray and initializes it with the given array.
+inline FloatArrayUniquePtr BuildTfLiteArray(const TfLiteFloatArray& other) {
+  return BuildTfLiteArray(other.size, other.data);
+}
+
+}  // namespace tflite
+
+#endif  // TENSORFLOW_LITE_ARRAY_H_