Timed out waiting for packet header

[mpicco]

Hello,
I am in the process of setting up a pair of NodeMCU ESP-32 units where one will act as a web server and the other, a web client. The end result will be a unit atop my ham radio tower (mounted on the antenna mast) that will provide me compass heading, temperature, humidity and barometric pressure. This data will be brought up on a graphics display near my ham radio bench that will display the data, along with a compass rose indicator of where the antenna is pointed.

The development platform being used is the Arduino IDE, set up to work with the ESP-32. The programs compile, but fail to upload and givie a message of: " ...Timed out waiting for packet header". The unit is being powered by the USB connection and there is nothing else connected to the NodeMCU ESP-32 unit. The Arduino IDE settings include the USB port; board selected is the ESP32 Dev Module; upload speed of 115200.

Any thoughts as to where I'd look to get this working?

Kind regards,
Michael
K6MLE

[ESP_Sprite]

This is a really generic error that just says 'can't communicate with the ESP32' and can be caused by lots of things: from the ESP32 not getting into boot mode to you having selected the correct com port.

Can you try connecting to the serial port that the NodeMCU provides directly and see if you get any output when you reset the ESP32? This at least indicates the unit is working and communicating OK.

While Arduino is trying to connect, can you hold the 'boot' button on the NodeMCU and tap the 'reset' button shortly? There are some known gotchas with the auto-reset circuitry, you may be running into that.

[mpicco]

Thank you for your response. I can confirm that there is activity on the TX pin following a reset. The operation of holding the boot button and tapping the reset button during the 'connect' attempt, did not produce any different result. Anything else I might try? I do have another pair of ESP32 units arriving today and will put them through their paces, but would really like to put the two I already have into good use.