I tested a fourth cable and it worked!!! Please disregard my previous question…I was just feeling frustrated, but not anymore!!! 
Regards
Claudio

Hi Claudio, I’m glad it’s working now! 
Yes, always double-check that you are using a good USB cable that has data pins (for example some USB cables that come with powerbanks only have power wires). So, if you connect them to your computer you can only power the ESP32 and you can’t upload any code to it.
Let me know if you experience any other trouble during the course! Regards,
Rui

I also have the same issue. Have gone through all the procedures and loaded drivers for CP210x USB to UART Bridge. I have tried numerous USB cables and still do not see the port.
The board I am using is the Node MCU 32S and I am using a Macbook pro.

Hi David, thanks for letting us know in another thread how you solved that issue.

David said in another post: “I initially had problems with serial port but now have solved that when I saw it was being blocked in Security settings. I now see the SLAB port fine.”

I have just come back to the ESP232 course after a while and seem to be defeated at the first hurdle as I have the same issue again with the port not showing up. It worked briefly but when I unplugged the board and plugged back in again not port! I did not change anything. Is there a way to diagnose this issue?

Hello David, I honestly don’t know why that’s happening to you… I have two Mac computers and I was able to install the drivers fine.

• Which board are you using? 
• Can you double-check according this Unit which serial chip does your board have? Read section “6. COM Port not found/not available” https://rntlab.com/esp32-troubleshooting-guide/

Thanks for your patience!

I do have the CP1202 chip. I have tried various cables and there are some that definitely never work. I have found one that periodically works, but it is not consistent. Sometimes yes and sometimes no, so clearly the chip and the drivers are working and the cable works too but the download does not work always only periodically

But is it working now? Is your computer recognizing the Port?
Basically, now sometimes the Download (uploading new code) fails?
I’m just trying to understand what’s your current problem… Thanks!

Actually I think I have 2 problems which are confusing. I just got a Port connection ok but am receiving this error:
    A fatal error occurred: Failed to connect to ESP32: Timed out waiting for packet header
Occasionally I lose the port connection, but this is more serious as even when I am connected I am not getting a download.

After pressing the Arduino IDE upload button, you need hold the ESP32 BOOT button to force the upload of new code. Pleas read “4. A fatal error occurred: “Failed to connect to ESP32: Timed out… Connecting…”” https://rntlab.com/esp32-troubleshooting-guide/
Does that solution work for you?

This did not seem to help. I am still getting the following error:
Arduino: 1.8.8 (Mac OS X), Board: “DOIT ESP32 DEVKIT V1, 80MHz, 921600, None”
Sketch uses 160169 bytes (12%) of program storage space. Maximum is 1310720 bytes.
Global variables use 11076 bytes (3%) of dynamic memory, leaving 283836 bytes for local variables. Maximum is 294912 bytes.
esptool.py v2.3.1
Connecting…….._____….._____….._____….._____….._____….._____….._____….._____….._____….._____
A fatal error occurred: Failed to connect to ESP32: Invalid head of packet (‘\x00’)
A fatal error occurred: Failed to connect to ESP32: Invalid head of packet (‘\x00’)
This report would have more information with
“Show verbose output during compilation”
option enabled in File -> Preferences.
 

Which board are you using David (can you post a link to where you purchase it)?
That’s the exact error that is solved by holding the BOOT button while you see the message “Connnecting….”. Basically, you need to force the ESP to go into flashing/uploading mode.
Double-check that you’re holding the BOOT/FLASH button and not the RESET button.
Thanks for your patience! 

Many thanks. This seems to have solved the downloading problem and speeds up downloads considerably. I am now getting consistent downloads without errors.

I’m happy to hear that!
Yes, unfortunately some ESP32 boards, you do need to hold the BOOT/FLASH button. Otherwise the new code fails to upload. I’ll mark this thread as “resolved”. If you have more questions, feel free to open a new question here: https://rntlab.com/ask-question/