How about a bit more information so we can help?
What MCU/board do you use?
Which sketch?
Which MLX90640 board do you have?
How did you connect the MLX 90640 and the MCU/board?
This is my circuit so basically I tried to direct the connection from the lens (SDL/SDA/VCC) but I insert a 4.7k resistor for SDA AND SDL I just remove it for picture, but the problem is still the same
" insert a 4.7k resistor for SDA AND SDL I just remove it for picture,"
Just to make sure. Did you have 4.7K resistors as pull-up to 3v3, on both SDA and SCL (as it should)? or where the serial ?
Hard to find information about this MLX90640 board. Is the board 3v3 VCC or 5V ?
Is the YELLOW wire to the MLX90640 connected to GND ??
background thoughts
It finds the the MLX90640, so the lines are connected correctly, but then the communication fails. I did not find information that the MLX90640 is using clock stretch (which fails on ESP32). You included reference link does not seem to have issues either. With unstable behavior I would predict it is pull-up (if not already on the MLX90640 board) or power supply that makes it unstable, or Wire speed / half-connected wires. Still it could be the MLX90640 itself..
Im seeing other components on your MLX90640 board that could be interfeaing with the ESP. You need the bare sensor or a breakout that doesn’t have other chips on it.
I am not sure it is the MLX90640.. not yet at least. .. double check the wiring and voltage. See my earlier question about the GND connection. You need pull-up if not already… keep the Wire at 100Khz..
Try an I2C SCANNER and run that multiple times.. (Arduino Playground - I2cScanner)
There appears to be some sort of microcontroller on the board along with the thermal sensor.
I do not think you can connect this to your project the way the guide is written because i think that other controller chip on the board will interfere with communication between your esp and the sensor.
I think you’re better off getting a breakout board from adafruit, sparkfun or someone else. Your chances of success would be better this way, the guide you’re following assumes you have a breakout.
What do you imagine removing the lens would accomplish?
You bought a cheap, completely unsupported sensor that apparently doesn’t come with operating instructions, and may be counterfeit and/or not fully functional.
If you bought an MLX-90640 module from Sparkfun, you get the genuine item, operating instructions, a getting started guide with libraries and example code, forum support and a pretty generous guarantee of functionality.
