Give that the Photon’s system clock (120 MHz) is almost twice as fast as the Core’s clock (72 MHz), do we need to adjust the SPI_CLOCK_DIV on the libraries that we port from the Core to the Photon?
The issue that I’m having is that after migrating from the Core to the Photon, the SD card reader of the [Adafruit TFT LCD shield] (https://learn.adafruit.com/adafruit-3-5-color-320x480-tft-touchscreen-breakout/bitmaps-spi-mode) that I’m using stops working.
SD.Begin() returns False, and I get
Error: CMD0 in the serial.
My suspicion is that the new SPI speed might be too fast for the SD SPI. The LCD does work though.
The libraries I’m using are: