char htmlResponse[35000];

Do you really need 35k for that little json?
Make it much much smaller or allocate dynamically.

Some code would be helpful. From what you've given it sounds like buf is not null terminated so strlen is crapping out.

const int* zeit_m[]

zeit_m (same for zeit_h) is an array of pointers, not an array of ints. You need to dereference these pointers to get the int that they point to.

if(*zeit_m[Wort] == minuten) {

Its just passing the return value to println() for debugging. Same as esp_err_t result; result = esp_deep_sleep_enable_ext0_wakeup((gpio_num_t)RTC_IN, 0) Serial.println(result); You can see the return values here: https://docs.espressif.com/projects/esp-idf/en/latest/api-reference/system/sleep_modes...

Hopefully someone who knows what they're talking about will chime in, but I'll throw in a few thoughts in the meantime: Are you using the API? I'm sure you'll have a lot more luck with that than starting from scratch fiddling with individual registers, at least as a starting point for your own custo...

Try volatile

During "wait x" is the ULP running at full power, such as full power is for the ULP? I'm guessing something around 5~10 µA? ULP will draw a lot more than that when it's running. I'm not aware of anything can get close to 1uA/MHz currently. It's probably somewhere in the 200uA-2mA range. You might c...

Blow the dust off the ULP and put it to work for a change, bit-banging some APA-type RGB LEDs. I wrote a little C++ library to do just that, built with Arduino in mind (but it will work with esp-idf too). It can also be used as a controller for FastLED (and NeoPixelBus, kind of). https://github.com/...

The ULP program begins when ulp_run is called, and RTC_CNTL_RDY_FOR_WAKEUP can be 1 even when the SoC is active (maybe you're expecting it to only be set when in deep sleep?). So what's happening is that the ULP is running, checking that bit, and then generating the interrupt *before* the SoC has en...

What is the interval between SPI/flash activity? That will determine if/which sleep modes are viable. If you wanted to be very aggressive about it, you might even use the ULP to bitbang SPI and buffer the received data, while the SoC wakes intermittently to write the data to flash when the buffer is...