Ok, It seems that this problem is to do with the clock line. There is some documentation online about it. First of all, I'm going to do a logic analysis of the clock and data lines with the 3.9k which I've got. Then I'm going to wire in the 2.2k instead of the 3.9k, and look for any difference. Then...

Strange. Component tolerances? That would mean your working sensor is very close to non-working. I had a similar situation on the SPI bus. Two devices worked on the breadboard, then on a 3m cable the closer one did not. I'd say that the sum of all cables on the bus influences the whole communicatio...

Ok, an update...

I don't know what is going on here, but that particular sensor cannot work with ESP32 over 3m, it only works with Arduino that way.

I've used another sensor of the same model, and the new sensor does work with ESP32 over the 3m...

What the hell?!?!

Hi Hexman, Thanks for your reply... I read that 4.7k is best for 5v, and from that I just guessed that 3.3v would need a little lower, hence my 3.9k resistor guess, but now you mention it, I'll use 2.2k. I have two of them taped to the project, ready to put in after my tests. Anyway, I've since got ...

I've just done some more tests and I can confirm that the BH1750 is working, and that it works when the wires are short.

Why would it work for a Nano but not for the ESP32??!?

Hi everyone, I've got 2 I2C devices, an ADS1115 ADC and BH1750 Light sensor. I did a test circuit using a breadboard (whtout pullups) and it all worked as expected. However, now I put the circuit in place, the Light Sensor doesn't work. I've taken away the ADS1115, and the BH1750 still doesn't work....

Hi everyone, An update for those who are interested. You can get Modbus to work with the ESP32. The libraries for Arduino do not work. For some reason, they cause the transmission to the Modbus device to be messed up. The timing is not right and the RE/DE control doesn't work properly. This is becau...

Hi everyone, I need this to work, so I decided to try to diagnose and fix it myself. The problem is that the ESP32 sends gibberish to the Modbus device. The device then doesn't respond because it doesn't understand what the hell the ESP32 is saying! If you look at the pulse train, you can see that t...

Hey, I also have this exact problem and I'm really interested to know the solution.

What do we know so far?

Antony

Hi everyone,

What is the proper way to reconnect to WiFi?

Let's say I've connected to my router, then the router is restarted. How should I handle this from within the ESP32?

Thanks, Antony