hello-world example can't load model (TFMIC-30)

[maxgerhardt]

Running ESP-IDF 4.x + Arduino-ESP32 2.x and trying the hello-world example, the output is wrong. It seems the interpreter loads the model but then interpreter->input(0); and interpreter->output(0); returns vectors that have an extremely high zero-point and a scale of either 0 or -nan. This ofc makes the quantized x & y values wrong, too. Specifically, the output y is always 0.

Quantized x: -1 input zero point 1073421472 scale -nan
Quantized y: -48 output zero point 1073421456 scale 0.000000
x_value: 0.000000, y_value: -0.000000

Quantized x: -1 input zero point 1073421472 scale -nan
Quantized y: -48 output zero point 1073421456 scale 0.000000
x_value: 0.314159, y_value: -0.000000

This is running on a regular ESP32 dev board with no PSRAM. Example projects see https://github.com/maxgerhardt/pio-esp32-tfmicro-example, it uses PlatformIO for compilation. Any help is appreciated.

[maxgerhardt]

Note: Manually fixing input and output quantization with values read from the model and https://netron.app/ still leads to wrong model output.

  int8_t x_quantized = x * 40.69345526012819f + 128;
//..
  float y = (y_quantized - 4) * 0.008472034707665443f;

There must be something wrong when TFlite or Flatbuf decodes the model...

Quantized x: 12 input zero point 1073421424 scale -nan
Quantized y: 16 output zero point 1073421408 scale 0.000000
x_value: 3.455752, y_value: 0.101664

Quantized x: 25 input zero point 1073421424 scale -nan
Quantized y: 16 output zero point 1073421408 scale 0.000000
x_value: 3.769912, y_value: 0.101664

Also, updating the platform to use ESP-IDF 5.1.4 did not help, it's the same output pretty much.

[vikramdattu]

Hi @maxgerhardt did you try the example from esp-tflite-micro without Arduino? https://github.com/espressif/esp-tflite-micro/tree/master/examples/hello_world Do you find results with this problematic too?