No announcement yet.

Using UART TTL pins of gen4 IOD

  • Filter
  • Time
  • Show
Clear All
new posts

  • Using UART TTL pins of gen4 IOD

    I have an gen4 IOD (32T if that matters) device which im programming using the Arduino IDE, utilizing the 4D-UPA. The Display is connected using a 10-Pin (IIRC) FFC cable. My objective is to establish a serial (TTL) communication channel to another ESP32 board; and while I can use a HTerm connection from the computer via the USB port to talk to the IOD device, I cannot do so through the TTL pins present on the 4D-UPA. To clarify, because there seem multiple pins RX/TX, I am using the Friction-Fit header pins (H1) but have pin headers soldered to assure proper connections.

    Transmitting data from gen4-IOD to the other board works, but the RX pin of the gen4-IOD is not receiving any data. I've read in a different post that the issue might be that the usb communication channel is using said pins.

    After reading the datasheet prior to purchasing I was under the impression that the UART was accessible via the UPA (Section 4.1., This is somewhat confusing to me, but then again having the RX line served by an IC on the UPA would perfectly explain my issue. Could you please clarify this?

    Is there any method of reconfiguring the UART of the ESP8266 to any of the exposed GPIO pins (0, 16) . Is there any documentation on this issue?

    Would it be possible to utilize a 30pin FFC cable to access other GPIO pins of the gen4 IOD? I've seen that the 30pin-FFC carries some pins that I know how to remap the UART to.

    As a method of last resort, would it be possible to disable to on-board USB-TTL converter of the UPA and use an external FTDI chip on said pins to program the gen4-IOD?

    Best regards,

  • #2
    Hi Fabian,

    The 4D-UPA won't allow serial communication to a host due to the USB-Serial chip on the Rx Tx pins. Please check the link below for further information and a solution to this post.

    Thank you.

    Best Regards,