uart5 rx

With the Espruino board, I am using a serial display and I am also using the SD card. The serial display only requires TX pin on the Espruino, the RX pin is unused. Right now I am using C10 (UART4 TX) for the display and I have left C11 (UART4 RX) unconnected.
I am wondering if I can instead use UART5 TX for the display even when I have the SD card in use? In the list of pins not on connectors I see D2 being used for SD card and it also has UART5 RX, which I assume means that if I do not use the SD card then I could use UART5.
But what if I use the SD card, can I use the UART5 TX pin for the serial display with no problems? The communication with the display is only one direction. This would allow me an extra serial port. (I am running out of pins).

You should be able to, as long as you specify tx but not rx in Serial5.setup().

As @DrAzzy says, you should be fine.

The way pin assignments work on the F103 in the Espruino is a bit crazy: peripheral pins are specified per-peripheral rather than per-pin, but you can choose between input/output (or a peripheral) on a per-pin basis.

However, as D2 isn't being used for anything special for the SD card (it's just a basic GPIO pin) you're absolutely fine.

Thank you, both. I am working on a single sided circuit board for my power project. There is still time to include this change.