diff --git a/mlearning/darknet/Makefile b/mlearning/darknet/Makefile
index 627245fbd1e..94e80ba9787 100644
--- a/mlearning/darknet/Makefile
+++ b/mlearning/darknet/Makefile
@@ -74,6 +74,7 @@ CSRCS   +=$(SRC)/iseg_layer.c
 CFLAGS += -Wno-shadow -Wno-strict-prototypes -Wno-unknown-pragmas
 
 MODULE = $(CONFIG_DARKNET_YOLO)
+DARKNET_YOLO_VER = $(patsubst "%",%,$(strip $(CONFIG_DARKNET_YOLO_VER)))
 
 darknet.zip:
 	$(Q) curl -L https://github.com/pjreddie/darknet/archive/refs/heads/$(DARKNET_YOLO_VER).zip -o darknet.zip
diff --git a/mlearning/tflite-micro/CMakeLists.txt b/mlearning/tflite-micro/CMakeLists.txt
index a2756e7c921..919dcd14660 100644
--- a/mlearning/tflite-micro/CMakeLists.txt
+++ b/mlearning/tflite-micro/CMakeLists.txt
@@ -76,7 +76,9 @@ if(CONFIG_TFLITEMICRO)
   if(CONFIG_TFLITEMICRO_DEBUG)
     list(APPEND COMMON_FLAGS -DTF_LITE_SHOW_MEMORY_USE)
     list(APPEND COMMON_FLAGS -DTF_LITE_USE_CTIME)
-  else()
+  endif()
+
+  if(NOT CONFIG_TFLITEMICRO_DEBUG AND NOT CONFIG_TFLITEMICRO_SYSLOG)
     list(APPEND COMMON_FLAGS -DTF_LITE_STRIP_ERROR_STRINGS)
   endif()
 
diff --git a/mlearning/tflite-micro/Makefile b/mlearning/tflite-micro/Makefile
index aba043805e7..179d0e9c32b 100644
--- a/mlearning/tflite-micro/Makefile
+++ b/mlearning/tflite-micro/Makefile
@@ -38,6 +38,7 @@ tflite-micro.zip:
 	$(Q) patch -d $(TFLM_UNPACK) -p1 < 0001-dequantize-int8.patch
 	$(Q) patch -d $(TFLM_UNPACK) -p1 < 0002-quantize-int8.patch
 	$(Q) patch -d $(TFLM_UNPACK) -p1 < 0003-mean-int8.patch
+	$(Q) patch -d $(TFLM_UNPACK) -p1 < 0004-tflite-add-extern-C-to-main-function-to-avoid-c-mang.patch
 
 # Download and unpack tarball if no git repo found
 ifeq ($(wildcard $(TFLM_UNPACK)/.git),)
@@ -60,7 +61,9 @@ COMMON_FLAGS += -DTF_LITE_DISABLE_X86_NEON
 ifneq ($(CONFIG_TFLITEMICRO_DEBUG),)
 COMMON_FLAGS += -DTF_LITE_SHOW_MEMORY_USE
 COMMON_FLAGS += -DTF_LITE_USE_CTIME
-else
+endif
+
+ifeq ($(CONFIG_TFLITEMICRO_DEBUG)$(CONFIG_TFLITEMICRO_SYSLOG),)
 COMMON_FLAGS += -DTF_LITE_STRIP_ERROR_STRINGS
 endif
 
@@ -106,11 +109,42 @@ endif
 # extra hardware support.
 -include $(TFLM_DIR)/tensorflow/lite/micro/nuttx/Makefile
 
+PROGNAME  :=
+PRIORITY  :=
+STACKSIZE :=
+MAINSRC   :=
+
 ifneq ($(CONFIG_TFLITEMICRO_TOOL),)
-MAINSRC   = tflm_tool.cc
-PROGNAME  = tflm
-PRIORITY  = $(CONFIG_TFLITEMICRO_TOOL_PRIORITY)
-STACKSIZE = $(CONFIG_TFLITEMICRO_TOOL_STACKSIZE)
+PROGNAME  += tflm
+PRIORITY  += $(CONFIG_TFLITEMICRO_TOOL_PRIORITY)
+STACKSIZE += $(CONFIG_TFLITEMICRO_TOOL_STACKSIZE)
+MAINSRC   += tflm_tool.cc
+endif
+
+ifneq ($(CONFIG_TFLITEMICRO_HELLOWORLD),)
+TFLM_HW_DIR    := $(TFLM_UNPACK)/tensorflow/lite/micro/examples/hello_world
+TFLM_HW_MODELS := $(TFLM_HW_DIR)/models
+
+ifeq ($(wildcard $(TFLM_UNPACK)/.git),)
+$(TFLM_HW_MODELS)/hello_world_float_model_data.h \
+$(TFLM_HW_MODELS)/hello_world_int8_model_data.h: tflite-micro.zip
+endif
+
+$(TFLM_HW_MODELS)/hello_world_float_model_data.h:
+	$(Q) ( cd $(TFLM_HW_MODELS) && xxd -i hello_world_float.tflite ) | \
+		sed -e 's/hello_world_float_tflite/g_hello_world_float_model_data/g' > $@
+
+$(TFLM_HW_MODELS)/hello_world_int8_model_data.h:
+	$(Q) ( cd $(TFLM_HW_MODELS) && xxd -i hello_world_int8.tflite ) | \
+		sed -e 's/hello_world_int8_tflite/g_hello_world_int8_model_data/g' > $@
+
+context:: $(TFLM_HW_MODELS)/hello_world_float_model_data.h
+context:: $(TFLM_HW_MODELS)/hello_world_int8_model_data.h
+
+PROGNAME  += tflm_hello
+PRIORITY  += $(CONFIG_TFLITEMICRO_HELLOWORLD_PRIORITY)
+STACKSIZE += $(CONFIG_TFLITEMICRO_HELLOWORLD_STACKSIZE)
+MAINSRC   += $(TFLM_HW_DIR)/hello_world_test.cc
 endif
 
 CFLAGS   += ${COMMON_FLAGS}
diff --git a/mlearning/tflite-micro/tflm_tool.cc b/mlearning/tflite-micro/tflm_tool.cc
index 8edcf45a49b..aa3a5934ab3 100644
--- a/mlearning/tflite-micro/tflm_tool.cc
+++ b/mlearning/tflite-micro/tflm_tool.cc
@@ -24,6 +24,8 @@
  * Included Files
  ****************************************************************************/
 
+#include <stdio.h>
+#include <stdlib.h>
 #include <unistd.h>
 
 #include <cstdint>
@@ -44,7 +46,7 @@ static void usage(void)
     "[ -C       ] Compile tflite model into c++ codes.\n"
     "[ -E       ] Do once evaluation (for profiling).\n"
     "[ -i <str> ] Readable model file path.\n"
-    "[ -o <str> ] Writable c++ file path.\n"
+    "[ -o <str> ] Writable c++ file path (required with -C).\n"
     "[ -p <str> ] Prefix of compiled code.\n"
     "[ -a <int> ] Arena size (mempool).\n"
     "[ -h       ] Print this message.\n");
@@ -93,13 +95,19 @@ extern "C" int main(int argc, FAR char* argv[])
         }
     }
 
-  if (!modelFileName || !codeFileName)
+  if (!modelFileName || (need_compile && !codeFileName))
     {
       usage();
       return -1;
     }
 
   std::ifstream ifs(modelFileName, std::ios::binary);
+  if (!ifs)
+    {
+      printf("Failed to open model file: %s\n", modelFileName);
+      return -1;
+    }
+
   ifs.seekg(0, std::ios::end);
   size_t modelSize = ifs.tellg();
   std::unique_ptr<uint8_t[]> pModel(new uint8_t[modelSize]);
@@ -108,17 +116,15 @@ extern "C" int main(int argc, FAR char* argv[])
   ifs.read(reinterpret_cast<char*>(pModel.get()), modelSize);
   ifs.close();
 
-  /* HACK: can change operators here. */
-
   tflite::MicroMutableOpResolver<8> resolver;
-  resolver.AddConv2D(tflite::Register_CONV_2D_INT8());
-  resolver.AddMaxPool2D(tflite::Register_MAX_POOL_2D_INT8());
-  resolver.AddQuantize(tflite::Register_QUANTIZE_FLOAT32_INT8());
-  resolver.AddDequantize(tflite::Register_DEQUANTIZE_INT8());
-  resolver.AddMean(tflite::Register_MEAN_INT8());
+  resolver.AddConv2D();
+  resolver.AddMaxPool2D();
+  resolver.AddQuantize();
+  resolver.AddDequantize();
+  resolver.AddMean();
   resolver.AddReshape();
-  resolver.AddFullyConnected(tflite::Register_FULLY_CONNECTED_INT8());
-  resolver.AddSoftmax(tflite::Register_SOFTMAX_INT8());
+  resolver.AddFullyConnected();
+  resolver.AddSoftmax();
 
   std::unique_ptr<uint8_t[]> pArena(new uint8_t[arenaSize]);
 
@@ -127,11 +133,22 @@ extern "C" int main(int argc, FAR char* argv[])
     resolver, pArena.get(), arenaSize, nullptr,
     reinterpret_cast<tflite::MicroProfilerInterface*>(&profiler));
 
-  /* HACK: can add testcases here. */
+  TfLiteStatus status = interpreter.AllocateTensors();
+  if (status != kTfLiteOk)
+    {
+      printf("AllocateTensors failed: %d\n", status);
+      return -1;
+    }
 
   if (need_invoke)
     {
-      interpreter.Invoke();
+      status = interpreter.Invoke();
+      if (status != kTfLiteOk)
+        {
+          printf("Invoke failed: %d\n", status);
+          return -1;
+        }
+
       profiler.LogCsv();
       profiler.LogTicksPerTagCsv();
     }