MASTER SIDE uint8_t txByte_master = 0xA5; // Byte to senduint8_t rxByte_master = 0x00; // Received bytevolatile uint16_t count = 0;uint8_t dummyTx = 0x00;uint8_t dummyRx = 0x00;volatile uint8_t spi_ready = 0; // Flag to indicate SPI transfer complete...