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enter image description here

This is my design of a simple ESP32-S3-MINI USB and BLE HID device.

If I connect it to the PC it is only momentarily recognized and then disappears to show up again one second later. It is on and off constantly. What could be the possible issue? The rest you don't see is just some buttons.


Update

This is the output on the serial monitor:

invalid header: 0xa5ff005a 
invalid header: 0xa5ff005a 
invalid header: 0xa5ff005a 
invalid header: 0xa5ff005a 
invalid header: 0xa5ff005a 
invalid header: 
ESP-ROM:esp32s3-20210327 
Build:Mar 27 2021 
rst:0x15 (USB_UART_CHIP_RESET), boot:0x8 (SPI_FAST_FLASH_BOOT) 
Saved PC:0x40048839 
invalid header: 0xa5ff005a 
invalid header: 0xa5ff005a 
invalid header: 0xa5ff005a 
invalid header: 0xa5ff005a 
invalid header: 0xa5ff005a 
invalid header: 0xa5ff005a 
.....
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  • \$\begingroup\$ The regulator XC6206P is too slow to handle the fast steps in the load current during RF activity. A 220 uF tantal capacitor as C4 might help but violates USB specifications related to inrush current. The nearly unreadable diagram of "Load transient input response characteristics" in the datasheet tries to hide the problem. \$\endgroup\$
    – Jens
    Sep 12, 2023 at 13:23

1 Answer 1

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It's been a long time since I have programmed an ESP32 but, I think you need to pull GPIO0 to GND on boot if you want the bootloader to run. Looking at your schematic, it seems the GPIO0 is floating. https://docs.espressif.com/projects/esptool/en/latest/esp32/advanced-topics/boot-mode-selection.html

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  • \$\begingroup\$ But would this reset the ESP constantly? \$\endgroup\$ Sep 16, 2023 at 23:16
  • \$\begingroup\$ 0x15 shows a brownout due to not stable VDD, right? \$\endgroup\$ Sep 16, 2023 at 23:39
  • \$\begingroup\$ You would need a push button between GND and the GPIO0 pin so you toggle it only when you want to program. \$\endgroup\$
    – mouelle
    Sep 18, 2023 at 0:17
  • \$\begingroup\$ @MarkusImmig, looking online at some posts, it seems the "invalid header: 0xa5ff005a" message is due to an unprogrammed ESP32. Have you succeded in loading your porgram on the ESP32? \$\endgroup\$
    – mouelle
    Sep 18, 2023 at 12:48
  • \$\begingroup\$ No, unfortunately I did not design the reset button. On the S3-Mini the pin 0 is not accessible from outside to bridge. \$\endgroup\$ Sep 21, 2023 at 21:36

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