`SD_Time.ino` not compatible with Wireless Tracker – is SD card access possible?

[musuyaba]

I’ve been trying to run the SD_Time.ino example on the SD_Time.ino, but it doesn’t work out of the box.

This example is available via the Arduino IDE under:

File > Examples > Heltec ESP32 Dev-Boards > SD > SD_Time

---

Problem: GPIOs don’t match

The sketch uses these SPI pins for SD card access:

SD_CS   -- GPIO22  
SD_MOSI -- GPIO23  
SD_SCK  -- GPIO17  
SD_MISO -- GPIO13

However, these GPIOs are not available or exposed on the Wireless Tracker, as confirmed by the official datasheet. So the example cannot work as-is on this board.

---

Datasheet check – FSPI-capable GPIOs on Wireless Tracker

From the board's datasheet, the following GPIOs are exposed and associated with FSPI:

SPI Signal	GPIO	Pin Label	Function
CS	34	FSPICS0	Chip Select
CLK	36	FSPICLK	Clock
MOSI	35	FSPID	Master Out
MISO	37	FSPIQ	Master In

---

SPI Bus Confusion – Need Clarification

From my understanding, the ESP32-S3 supports two SPI buses: FSPI and HSPI. I can see that FSPI-related pins are exposed on the header, but I'm not sure if:

1. FSPI or HSPI is already in use internally by the Wireless Tracker’s OLED or LoRa module
2. If so, is there a safe way to disable or remap those peripherals to free up one of the SPI buses for use with an SD card?

I’d like to avoid breaking core functionality (like display or radio), so I'm hesitant to override anything without confirmation.

---

Questions

1. Are the above GPIOs the correct ones to use for SD.begin(csPin, spiInstance) on the Wireless Tracker?
2. Is either FSPI or HSPI already used by the OLED or LoRa module?
3. If one is used, can it be safely disabled in the Arduino environment to allow SD card access?
4. Is there an official/recommended way to connect and use an SD card on this board?

---

Since SD_Time.ino is included directly in the Heltec Arduino library examples, it would be very helpful to know if a version of it is expected to work with the Wireless Tracker, or if SD support is not available on this board due to shared hardware limitations.

Thanks in advance for any insight!