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Solution: ESP32 Pin GPIO0



ESP32 does not start in the program after installing download of a program


The PIN GPIO0 G0 should not be used as it is used for booting and installing software, firmware, sketch programs for the BOOT signal.






Extract from the esp32 Wroom 32 data sheet for the solution of the pins GPIO 0 G0 and EN (Module Enable)




Using GPIO0 on ESP32 WROOM 32 node MCU

Pin Default SPI Boot Download Boot

GPIO0 Pull-up 1 0

GPIO2 Pull-down Don’t-care 0


The pins such as Power-on-reset, GPIO0 GPIO2, EN are used during the download of a program

The ESP32 is called download when installing a program. Software on the Internet uses the term upload.


During the chip’s system reset release (power-on-reset, RTC watchdog reset and brownout reset), the latches of the strapping pins sample the voltage level as strapping bits of ”0” or ”1”, and hold these bits until the chip is powered down or shut down. The strapping bits configure the device’s boot mode, the operating voltage of VDD_SDIO and other initial system settings. Each strapping pin is connected to its internal pull-up/pull-down during the chip reset. Consequently, if a strapping pin is unconnected or the connected external circuit is high-impedance, the internal weak pull-up/pull-down will determine the default input level of the strapping pins. To change the strapping bit values, users can apply the external pull-down/pull-up resistances, or use the host MCU’s GPIOs to control the voltage level of these pins when powering on ESP32.



In addition, the PIN EN must be set to High after the software has been uploaded.



Therefore, it is better to use the PIN G2 GPIO2 right next to it as the output PIN and leave the GPIO0 G0 for the boot function




Small test program to see if ESP32 is running. Output on the Serial Monitor


void setup() {




void loop() {

  Serial.println("TEST ESP-WROOM-32 if it works");






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