Communication inquiry using esp32 about tf03k HOT 4 OPEN

I haven't looked at this code in a while, I'll try and come back up to speed. In the meantime, try using a USB -ttl adapter to communicate using a terminal program on your PC to make sure it isn't an ESP issue

from tf03k.

Thanks for your reply. There is something strange. I connected usb to TTL to my TF03, but there doesn't seem to be any power from TF03K's VCC. And I tried to check the serial data by connecting usb to TTL to the PC, but it seems that no data is coming in. However, the display of TF03K is normal. Do I need to do anything else to TF03K other than RX, GND, and connection? Are there any options?

from tf03k.

I remember having to return a TF03 unit because it didn't actually have TTL serial so that is always a potential culprit. I think they are sold more often without serial than with but then usually, the serial port on the case is blanked off. Based on your last response though, I think you have it hooked up wrong.

TF03K     ESP32
VCC <----- 3.3V
TX  -----> RX
GND <----- GND

Remember the serial pins are always relative to what that device is doing so you want the TF03K's transmit pin connected to the ESP32's receive pin.

from tf03k.

I remember having to return a TF03 unit because it didn't actually have TTL serial so that is always a potential culprit. I think they are sold more often without serial than with but then usually, the serial port on the case is blanked off. Based on your last response though, I think you have it hooked up wrong.

TF03K     ESP32
VCC <----- 3.3V
TX  -----> RX
GND <----- GND

Remember the serial pins are always relative to what that device is doing so you want the TF03K's transmit pin connected to the ESP32's receive pin.

Thank you.
I connected TX->RX as you instructed, but there is no signal.
Even if I connect it to a PC or ESP32, it doesn't work.
It seems that the TF03K I have is not sending serial.
I think I'll have to buy another TF03K.

from tf03k.