Constant ws2818_rgb_led_spi_driver::timings::PI_SPI_HZ

pub const PI_SPI_HZ: u32 = 15_600_000;

The frequency for the SPI device that should be used. While this was developed I focused on Raspberry Pi. Works on other Linux systems with SPI device probably too if they have a similar frequency. Otherwise you may need to change the values in encoding.rs.