My bad. I made 2 mistakes:
1 - I selected the wrong board (Teensy iso ESP32)
2 - In my old code I inluded "lwip/apps/sntp.h". Found out that this lib is deprecated. Replacement is "esp_sntp.h".
Now my sketch compiles without errors.

Thanks for looking into this.

There are 2 versions of the sntp library in Arduino. I just re-installed the Arduino IDE (v 2.3.3) and the ESP libraries for Arduino. I had the same problem using the previous version of the IDE. The problem is the the sntp.h files have contradicing declarations for the function sntp_getoperatingmod...

Thanks for the clarification. Bottom line is that I have to monitor the connection state by my own code and I cannot rely 100 % on the automatic reconnection. I also assume that having a wifi connection does not warrant that I'm connected to the internet, right? I'm not sure what my router does when...

Hello, I'm new to ESP32 WiFi and I'm exploring some of the features. When I set AutoReconnect to 'true' using the WiFi.setAutoReconnect() function I expect that ESP32 will immediately attempt to re-establish the WiFi connection when that connection is lost. To test this, I used the function WiFi.dis...

My Arduino IDE (v 2.3.2) is still using ESP IDF version 4.4.6. The latest version of IDF is 5.2. Questions: 1. Is it possible to upgrade IDF to the lastest (or at least a more more recent) version w/o breaking the Arduino IDE? 2. Is there a significant advantage in doing this? 3. Is there a dependen...

Thanks for the advice. IMHO the getString() function is pretty useless for c-strings... (unless of course one only uses strings of a fixed length). While we're at it: is there an easy way to get a dump of all keys in a namespace (c-code using Arduino IDE). I'm at a loss when it comes to python and I...

This thought just crossed my mind: maybe this is a (silly) work-around: store the c-string as a byte array using putBytes() ? Then I can get the number of bytes stored using getBytesLength() and then get the array with the actual c-string without knowing the length of the c-string...

The preferences documentation points out that the function size_t getString(const char* key, char* value, size_t len); requires the exact length of the stored char array or else it will fail. My string has a variable length, defined by user input. Of course the char array has a fixed length, but th...

Nice catch! Indeed, ADC1_CHANNEL_6 is defined in driver/adc.h as number 6 and I wrongly assumed that it was the equivalent of GPIO_NUM_34. Consequently my code was messing with GPIO6, which is part of the Flash interface. No wonder that my ESP did crazy things.
Thanks.

I'm using ESP32 DEVkit C, chip version 1. ESP Arduino library version 1.0.6 Arduino IDE version 1.8.13 Problem description: I'm getting input from the serial monitor (through USB) into my application. Since the length of the input is variable, I use the function "Serial.readBytesUntil('\n', incoming...