Struct rpi_memory_display::MemoryDisplay

pub struct MemoryDisplay { /* fields omitted */ }

Sharp Memory Display

Implementations

impl MemoryDisplay

pub fn new(
    spi_bus: Bus,
    spi_ss: SlaveSelect,
    cs_pin: u8,
    width: usize,
    height: u8
) -> Result<Self>

Initializes a new MemoryDisplay. The spi_ss pin should be left disconnected (but will still get toggled by the hardware). It is replaced by the cs GPIO pin.

pub fn set_clock_speed(&mut self, clock_hz: u32) -> Result<()>

Sets the SPI clock frequency in Hz.

Default value is 2Mhz (2000000). The spec for the Memory Display states a typical clock speed of 1Mhz, and a maximum speed of 2Mhz. The screens often do respond at a higher speed (e.g. 8MHz) but that will raise the internal temperatures and may lower the functional life of your screen.

pub fn clock_speed(&self) -> Result<u32>

Gets the SPI clock frequency in Hz.

pub fn set_spidev_bufsiz(&mut self, spidev_bufsiz: usize)

Sets the SPI device buffer size (as configured by the spidev.bufsiz option in boot/cmdline.txt on the Raspberry Pi).

You can read the current spidev.bufsiz by doing: cat /sys/module/spidev/parameters/bufsiz

The default value for the Pi (and this library) is 4096 bytes.

pub fn spidev_bufsiz(&self) -> usize

Gets the currently configured spidev.bufsiz for this library only. To get the real configured value for the hardware read /sys/module/spidev/parameters/bufsiz.

pub fn clear(&mut self) -> Result<()>

Clears the screen.

pub fn update<T: AsRef<[u8]>>(&mut self, pixels: T) -> Result<()>

Updates the display. Only lines that have changed since the last clear/update/refresh are sent to the display.

The pixels buffer can be any u8 slice where each bit represents a single black/white pixel (8 pixels per u8). MemoryDisplayBuffer provides a convenient interface to such a buffer.

Trait Implementations

impl Debug for MemoryDisplay

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.