Help with Pinout for core400s - No serial data received

[Samsolon1337]

Hey, hello, I followed your tutorial for the Levoit Core400s, but when using
esptool run <levoit-configuration>.yaml
I get the error message, that no serial data has been received.

That also matchey with my usb to ttl converter.

My guess is, that I am not enabling the bootloader correctly on the esp32 (I wanna overwrite the onboard esp32)(I have a backup)

Here are my connections:

Esp32-J1 | USB to TTL (waveshare)
—————————————————————
1[TX]    | TXD
2[RX]    | RXD
3[GND]   | GND
4[3.3V]  | VCC set to 3.3V
5[IO0]   | GND

This is my first time using a USB-TTL adapter. So i just want to make sure I understood the connections correctly.

Additional Information:

• If I shortcircut TXD and RXD the adapter works, meaning I dont think the stick is the problem.
• On my adapter I also have RTS, CTS
• /dev/ttyUSB0 permissions have been set to 777
• I also used the long esptool command that comes as a suggestion, after the flashing didnt work
• the firmware builds successfully

[tuct]

Hi,
First, i always recommend using a new/dedicated esp32 and not flashing the existing one!
Make sure you can get a backup of the original FW! this failed for me on most devices until i got a new USB/TTL device!
Here is info where to add the connections for custom esp32: #33

If you want to read /flash the original esp32 try this
Esp32-J1 | USB to TTL (waveshare)
—————————————————————
1[TX] | RXD !updated
2[RX] | TXD !updated
3[GND] | GND
4[3.3V] | VCC set to 3.3V
5[IO0] | GND****

RX of one end needs to be connected to TX on the other side! and vice versa

You can also try to power up the device, remove the 3.3V connection and keep all others, this might help if the usb/ttl device does not provide enough power (for esp32 it should work, but there might be other devices on that power rail)