Cascade

You inherited bring-up firmware for a board with three peripherals sharing GPIOA: USART1 for serial output, an I2C temperature sensor on I2C1 (address 0x48), and an SPI accelerometer on SPI1.

The I2C sensor works fine and UART prints output, but the SPI accelerometer always returns 0xFF for its WHO_AM_I register. The SPI clock and data lines look correct in the bus log, and chip select is being driven properly.

Something is clobbering the SPI pin configuration. Look carefully at how the GPIO port is being set up across the different init functions.

Output format (the values are whatever the sensors report): TEMP:<celsius> WHOAMI:0x<id>

Find and fix the bug so both peripherals report correct values.