Library that implements low-level protocol to the Hitachi HD44780-compatible LCD device.
Provides high-level API to the Hitachi HD44780-compatible LCD device. Uses 4-bit mode by default (only uses 4 data pins) plus two control pins (R/S and EN). R/W pin is not used and should be wired for "write" (low-level, 0).
The implementation is completely stateless. Client is free to reuse the same Display object
or to create one every time access to LCD is required.
Display also implements core::fmt::Write trait, so it could be used as a target of write!
macro.
This library does not depend on std crate and could be used in bare metal embedded development.
```rust
use core::fmt::Write; // for write! use lcd::*;
// implement HAL... struct HW { // any data needed to access low-level peripherals }
// implement Hardware trait to give access to LCD pins
impl Hardware for HW {
fn rs(&self, bit: bool) {
// should set R/S pin on LCD screen
}
fn enable(&self, bit: bool) {
// should set EN pin on LCD screen
}
fn data(&self, data: u8) {
// should set data bits to the LCD screen (only lowest 4 bits are used in 4-bit mode).
}
// optionally, override the following function to switch to 8-bit mode
fn mode(&self) -> lcd::FunctionMode {
lcd::FunctionMode::Bit8
}
}
// implement Delay trait to allow library to sleep for the given amount of time
impl Delay for HW {
fn delayus(&self, delayusec: u32) {
// should sleep for the given amount of microseconds
}
}
// optionally, implement InputCapableHardware to enable polling busy flag instead of delay
impl InputCapableHardware for HW {
fn rw(&self, bit: bool) {
// configure pins for input before setting R/W to 1
// configure pins for output after setting R/W to 0
}
fn read_data(&self) -> u8 {
0 // read data from the port
}
}
// create HAL and LCD instances let hw = HW { /* ... */ }; let mut lcd = Display::new(&hw);
// initialization lcd.init(FunctionLine::Line2, FunctionDots::Dots5x8); lcd.display( DisplayMode::DisplayOn, DisplayCursor::CursorOff, DisplayBlink::BlinkOff); lcd.entry_mode(EntryModeDirection::EntryRight, EntryModeShift::NoShift);
// print something write!(&mut lcd, "Hello, my number today is {: >4}", 42).unwrap(); ```
See lcd-example-bluepill for the working example
for the Blue Pill development board.
Licensed under either of
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.