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ESP32-U4WDH rtc wakeup

Posted: Thu Jun 26, 2025 6:54 am
by HInali Kapadiya
Board
ESP32-U4WDH(QFN-48(5x5) Dual Core RF Transceiver ICs)

Device Description
personal PCB

Version
esp-idf-v5.1.6

Operating System
Windows

Flash frequency
40MHz

Upload speed
115200

RTC pin
32K_XP 12 I/O GPIO32, ADC1_CH4, RTC_GPIO9, TOUCH9, 32K_XP (32.768 kHz crystal oscillator input)

Hardware connection
Connected (10k+20K)voltage divider from 5V to the GPIO32

Description
Hello,
I used the example C:\Espressif\frameworks\esp-idf-v5.1.6\examples\system\deep_sleep\main\ext_wakeup.c. I'm using GPIO32 to wake up the ESP32-U4WDH from deep sleep. The issue is that it enters deep sleep, but it doesn't wake up when GPIO32 goes high. It worked without any problems on the WROOM module. But no wakeup works with the ESP32-U4WDH. Here is the command:

esp_sleep_enable_ext0_wakeup(GPIO_NUM_32,1); //1 = High, 0 = Low

Moreover, from the hardware side, the pin is getting 3.3 volts and 0 volts (checked with a multimeter).