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//! # HT16K33 //! //! `ht16k33` is a driver for the [Holtek HT16K33 RAM Mapping 16\*8 LED Controller Driver with keyscan](http://www.holtek.com/productdetail/-/vg/HT16K33) chip. //! //! Currently, only the 28-pin SOP package type is supported. //! //! # Features //! //! - [x] Uses the [`embedded-hal`](https://crates.io/crates/embedded-hal) hardware abstraction. //! - [x] Supports `no_std` for embedded devices. //! - [ ] Supports all 20/24/28-pin SOP package types. //! - [x] Displays all 128 LEDs. //! - [ ] Reads keyscan. //! - [ ] Manages interrupts. //! - [ ] Manages slave devices. //! //! # Usage //! //! ## Linux-based platforms //! //! Using the recommended [`linux-embedded-hal`](https://crates.io/crates/linux-embedded-hal) //! crate which implements the `embedded-hal` traits for Linux devices, including I2C. //! //! ```!ignore //! # use failure::Error; //! use linux_embedded_hal::I2cdev; //! use ht16k33::HT16K33; //! # fn main() -> Result<(), Error>{ //! //! // The I2C device address. //! let address = 112u8; //! //! // Create an I2C device. //! let mut i2c = I2cdev::new("/path/to/i2c/device")?; //! i2c.set_slave_address(address as u16)?; //! //! let mut ht16k33 = HT16K33::new(i2c, address); //! //! # Ok(()) //! # } //! ``` //! //! ## Embedded platforms //! //! Using this crate without default features in your `Cargo.toml` like so: //! ```toml //! [dependencies] //! htk16k33 = { version = "*", features = [] } //! ``` //! //! ## All platforms, using I2C simulation //! //! Not all platforms have I2C support. The provided `ht16k33::i2c_mock` implements the //! `embedded-hal` traits for I2C. //! //! ``` //! # use failure::Error; //! use ht16k33::i2c_mock::I2cMock; //! use ht16k33::HT16K33; //! # fn main() { //! //! // The I2C device address. //! let address = 112u8; //! //! // Create a mock I2C device. //! let mut i2c = I2cMock::new(); //! //! let mut ht16k33 = HT16K33::new(i2c, address); //! //! # } //! ``` #![cfg_attr(not(feature = "std"), no_std)] #![doc(html_root_url = "https://docs.rs/ht16k33/0.4.0")] #![deny(missing_docs)] use embedded_hal as hal; #[cfg(feature = "serde")] use serde; mod constants; mod errors; mod types; pub mod i2c_mock; pub use errors::ValidationError; pub use types::{Dimming, Display, DisplayData, DisplayDataAddress, LedLocation, Oscillator}; pub use constants::{COMMONS_SIZE, ROWS_SIZE}; use hal::blocking::i2c::{Write, WriteRead}; /// The HT16K33 state and configuration. pub struct HT16K33<I2C> { i2c: I2C, // Device I2C address. address: u8, // Represents the desired values of the device, may not match // the current values if it has not been written recently. buffer: [DisplayData; ROWS_SIZE], // The following values are write-only registers and cannot // be queried from the device. We need to track their state // here and synchronize them with the device. oscillator_state: Oscillator, display_state: Display, dimming_state: Dimming, } impl<I2C, E> HT16K33<I2C> where I2C: Write<Error = E> + WriteRead<Error = E>, { /// Create an HT16K33 driver. /// /// # Arguments /// /// * `i2c` - The I2C device to communicate with the HT16K33 chip. /// /// # Examples /// /// ``` /// use ht16k33::i2c_mock::I2cMock; /// use ht16k33::HT16K33; /// # fn main() { /// /// // Create an I2C device. /// let mut i2c = I2cMock::new(); /// /// // The I2C device address. /// let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// /// # } /// ``` pub fn new(i2c: I2C, address: u8) -> Self { // Configure the initial values to match the power-on defaults. HT16K33 { address, i2c, buffer: [DisplayData::empty(); ROWS_SIZE], oscillator_state: Oscillator::OFF, display_state: Display::OFF, dimming_state: Dimming::BRIGHTNESS_MAX, } } /// Initialize the HT16K33. /// /// # Examples /// /// ``` /// # use failure::Error; /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// # fn main() -> Result<(), Error> { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// ht16k33.initialize()?; /// /// # Ok(()) /// # } /// ``` pub fn initialize(&mut self) -> Result<(), E> { // Enable the oscillator so we can use the device. self.set_oscillator(Oscillator::ON)?; // Set all values to match their defaults. self.set_display(Display::OFF)?; self.set_dimming(Dimming::BRIGHTNESS_MAX)?; // And clear the display. self.clear_display_buffer(); self.write_display_buffer()?; Ok(()) } /// Return the given I2C device, making this device unusable. /// /// # Examples /// /// ``` /// # use failure::Error; /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// # fn main() { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// i2c = ht16k33.destroy(); /// /// # } /// ``` pub fn destroy(self) -> I2C { // TODO Improve the naming? And somehow mark the state as destroyed so that // all other I2C accesses fail nicely? Should we continue to allow non-I2C access? self.i2c } /// Return the current display buffer. /// /// # Examples /// /// ``` /// # use failure::Error; /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// # fn main() { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// let &buffer = ht16k33.display_buffer(); /// /// # } /// ``` pub fn display_buffer(&self) -> &[DisplayData; ROWS_SIZE] { &self.buffer } /// Return the current oscillator state. /// /// # Examples /// /// ``` /// # use failure::Error; /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// # fn main() { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// let oscillator = ht16k33.oscillator(); /// /// # } /// ``` pub fn oscillator(&self) -> &Oscillator { &self.oscillator_state } /// Return the current display state. /// /// # Examples /// /// ``` /// # use failure::Error; /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// # fn main() { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// let display = ht16k33.display(); /// /// # } /// ``` pub fn display(&self) -> &Display { &self.display_state } /// Return the current dimming state. /// /// # Examples /// /// ``` /// # use failure::Error; /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// # fn main() { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// let dimming = ht16k33.dimming(); /// /// # } /// ``` pub fn dimming(&self) -> &Dimming { &self.dimming_state } /// Enable/disable an LED address in the display buffer. /// /// The buffer must be written using [write_display_buffer()](struct.HT16K33.html#method.write_display_buffer) /// for the change to be displayed. /// /// # Arguments /// /// * `location` - The LED location to update. /// * `enabled` - Set the LED on (true) or off (false). /// /// # Examples /// /// ``` /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// # use ht16k33::ValidationError; /// use ht16k33::LedLocation; /// # fn main() -> Result<(), ValidationError> { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// /// let led_location = LedLocation::new(0, 0)?; /// ht16k33.update_display_buffer(led_location, true); /// /// # Ok(()) /// # } /// ``` pub fn update_display_buffer(&mut self, location: LedLocation, enabled: bool) { // TODO Validate `address` parameter. // Turn on/off the specified LED. self.buffer[location.row_as_index()].set(location.common, enabled); } /// Clear contents of the display buffer. /// /// The buffer must be written using [write_display_buffer()](struct.HT16K33.html#method.write_display_buffer) /// for the change to be displayed. /// /// # Examples /// /// ``` /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// # fn main() { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// ht16k33.clear_display_buffer(); /// /// # } /// ``` pub fn clear_display_buffer(&mut self) { // TODO is there any advantage to iteration vs just assigning // a new, empty `[0; ROWS_SIZE]` array? for row in self.buffer.iter_mut() { *row = DisplayData::COMMON_NONE; } } /// Control the oscillator. /// /// # Arguments /// /// * `oscillator` - Set the oscillator On/Off. /// /// # Examples /// /// ``` /// # use failure::Error; /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// use ht16k33::Oscillator; /// # fn main() -> Result<(), Error> { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// ht16k33.set_oscillator(Oscillator::ON)?; /// /// # Ok(()) /// # } /// ``` pub fn set_oscillator(&mut self, oscillator: Oscillator) -> Result<(), E> { self.oscillator_state = oscillator; self.i2c.write( self.address, &[(Oscillator::COMMAND | self.oscillator_state).bits()], )?; Ok(()) } /// Control the display. /// /// # Arguments /// /// * `display` - Set the display On/Off. /// /// # Examples /// /// ``` /// # use failure::Error; /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// use ht16k33::Display; /// # fn main() -> Result<(), Error> { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// ht16k33.set_display(Display::HALF_HZ)?; /// /// # Ok(()) /// # } /// ``` pub fn set_display(&mut self, display: Display) -> Result<(), E> { self.display_state = display; self.i2c.write( self.address, &[(Display::COMMAND | self.display_state).bits()], )?; Ok(()) } /// Control the display dimming. /// /// # Arguments /// /// * `dimming` - Set the dimming brightness. /// /// # Examples /// /// ``` /// # use failure::Error; /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// use ht16k33::Dimming; /// # fn main() -> Result<(), Error> { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// ht16k33.set_dimming(Dimming::from_u8(4)?)?; /// /// # Ok(()) /// # } /// ``` pub fn set_dimming(&mut self, dimming: Dimming) -> Result<(), E> { self.dimming_state = dimming; self.i2c.write( self.address, &[(Dimming::COMMAND | self.dimming_state).bits()], )?; Ok(()) } /// Control an LED. /// /// # Arguments /// /// * `location` - The LED location to update. /// * `enabled` - Set the LED on (true) or off (false). /// /// # Examples /// /// ``` /// # use failure::Error; /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// use ht16k33::LedLocation; /// # fn main() -> Result<(), Error> { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// /// let led_location = LedLocation::new(0, 0)?; /// ht16k33.set_led(led_location, true)?; /// /// # Ok(()) /// # } /// ``` pub fn set_led(&mut self, location: LedLocation, enabled: bool) -> Result<(), E> { // TODO Validate `address` parameter. self.update_display_buffer(location, enabled); self.i2c.write( self.address, &[ location.row.bits(), self.buffer[location.row_as_index()].bits(), ], )?; Ok(()) } /// Write the display buffer to the HT16K33 chip. /// /// # Examples /// /// ``` /// # use failure::Error; /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// # fn main() -> Result<(), Box<Error>> { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// ht16k33.write_display_buffer(); /// /// # Ok(()) /// # } /// ``` pub fn write_display_buffer(&mut self) -> Result<(), E> { let mut write_buffer = [0u8; ROWS_SIZE + 1]; write_buffer[0] = DisplayDataAddress::ROW_0.bits(); for value in 0usize..self.buffer.len() { write_buffer[value + 1] = self.buffer[value].bits(); } self.i2c.write(self.address, &write_buffer)?; Ok(()) } /// Read the display buffer from the HT16K33 chip. /// /// # Examples /// /// ``` /// # use ht16k33::i2c_mock::I2cMock; /// # use ht16k33::HT16K33; /// # use std::error::Error; /// # fn main() -> Result<(), Box<Error>> { /// # let mut i2c = I2cMock::new(); /// # let address = 0u8; /// /// let mut ht16k33 = HT16K33::new(i2c, address); /// ht16k33.read_display_buffer(); /// /// # Ok(()) /// # } /// ``` pub fn read_display_buffer(&mut self) -> Result<(), E> { let mut read_buffer = [0u8; ROWS_SIZE]; self.i2c.write_read( self.address, &[DisplayDataAddress::ROW_0.bits()], &mut read_buffer, )?; for (index, value) in read_buffer.iter().enumerate() { self.buffer[index] = DisplayData::from_bits_truncate(*value); } Ok(()) } } #[cfg(test)] mod tests { extern crate std; use embedded_hal_mock as hal; use self::hal::i2c::{Mock as I2cMock, Transaction as I2cTransaction}; use super::*; use std::vec; const ADDRESS: u8 = 0; #[test] fn new() { let expectations = []; let mut i2c = I2cMock::new(&expectations); let ht16k33 = HT16K33::new(i2c, ADDRESS); i2c = ht16k33.destroy(); i2c.done(); } #[test] fn initialize() { let mut write_buffer = vec![super::DisplayDataAddress::ROW_0.bits()]; write_buffer.extend([0; super::ROWS_SIZE].iter().cloned()); let expectations = [ I2cTransaction::write( ADDRESS, vec![(super::Oscillator::COMMAND | super::Oscillator::ON).bits()], ), I2cTransaction::write( ADDRESS, vec![(super::Display::COMMAND | super::Display::OFF).bits()], ), I2cTransaction::write( ADDRESS, vec![(super::Dimming::COMMAND | Dimming::BRIGHTNESS_MAX).bits()], ), I2cTransaction::write(ADDRESS, write_buffer), ]; let mut i2c = I2cMock::new(&expectations); let mut ht16k33 = HT16K33::new(i2c, ADDRESS); ht16k33.initialize().unwrap(); i2c = ht16k33.destroy(); i2c.done(); } #[test] fn display_buffer() { let expectations = []; let mut i2c = I2cMock::new(&expectations); let ht16k33 = HT16K33::new(i2c, ADDRESS); let &buffer = ht16k33.display_buffer(); // Ensure it's the expected size. assert_eq!(buffer.len(), ROWS_SIZE); for row in buffer.iter() { // And because we just initialized this buffer, it should be all zeros. assert_eq!(row.bits(), 0u8); } i2c = ht16k33.destroy(); i2c.done(); } #[test] fn oscillator() { let expectations = []; let mut i2c = I2cMock::new(&expectations); let ht16k33 = HT16K33::new(i2c, ADDRESS); let &oscillator = ht16k33.oscillator(); assert_eq!(oscillator, Oscillator::OFF); i2c = ht16k33.destroy(); i2c.done(); } #[test] fn display() { let expectations = []; let mut i2c = I2cMock::new(&expectations); let ht16k33 = HT16K33::new(i2c, ADDRESS); let &display = ht16k33.display(); assert_eq!(display, Display::OFF); i2c = ht16k33.destroy(); i2c.done(); } #[test] fn dimming() { let expectations = []; let mut i2c = I2cMock::new(&expectations); let ht16k33 = HT16K33::new(i2c, ADDRESS); let &dimming = ht16k33.dimming(); assert_eq!(dimming, Dimming::BRIGHTNESS_MAX); i2c = ht16k33.destroy(); i2c.done(); } #[test] fn update_display_buffer() { let expectations = []; let mut i2c = I2cMock::new(&expectations); let mut ht16k33 = HT16K33::new(i2c, ADDRESS); let first_led = LedLocation::new(1, 4).unwrap(); let second_led = LedLocation::new(1, 5).unwrap(); // Turn on the LED. ht16k33.update_display_buffer(first_led, true); assert_eq!(ht16k33.display_buffer()[1].bits(), 0b0001_0000); // Turn on another LED. ht16k33.update_display_buffer(second_led, true); assert_eq!(ht16k33.display_buffer()[1].bits(), 0b0011_0000); // Turn off the first LED. ht16k33.update_display_buffer(first_led, false); assert_eq!(ht16k33.display_buffer()[1].bits(), 0b0010_0000); i2c = ht16k33.destroy(); i2c.done(); } #[test] fn clear_display_buffer() { let expectations = []; let mut i2c = I2cMock::new(&expectations); let mut ht16k33 = HT16K33::new(i2c, ADDRESS); let first_led = LedLocation::new(1, 4).unwrap(); let second_led = LedLocation::new(1, 5).unwrap(); // Turn on the LEDs. ht16k33.update_display_buffer(first_led, true); ht16k33.update_display_buffer(second_led, true); // Clear the display buffer. ht16k33.clear_display_buffer(); let &buffer = ht16k33.display_buffer(); // Ensure it's still the expected size. assert_eq!(buffer.len(), ROWS_SIZE); for row in buffer.iter() { // We just cleared this buffer, it should be all zeros. assert_eq!(row.bits(), 0u8); } i2c = ht16k33.destroy(); i2c.done(); } #[test] fn set_oscillator() { let expectations = [I2cTransaction::write( ADDRESS, vec![(super::Oscillator::COMMAND | super::Oscillator::OFF).bits()], )]; let mut i2c = I2cMock::new(&expectations); let mut ht16k33 = HT16K33::new(i2c, ADDRESS); ht16k33.set_oscillator(super::Oscillator::OFF).unwrap(); i2c = ht16k33.destroy(); i2c.done(); } #[test] fn set_display() { let expectations = [I2cTransaction::write( ADDRESS, vec![(super::Display::COMMAND | super::Display::OFF).bits()], )]; let mut i2c = I2cMock::new(&expectations); let mut ht16k33 = HT16K33::new(i2c, ADDRESS); ht16k33.set_display(super::Display::OFF).unwrap(); i2c = ht16k33.destroy(); i2c.done(); } #[test] fn set_dimming() { let expectations = [I2cTransaction::write( ADDRESS, vec![(super::Dimming::COMMAND | Dimming::BRIGHTNESS_MAX).bits()], )]; let mut i2c = I2cMock::new(&expectations); let mut ht16k33 = HT16K33::new(i2c, ADDRESS); ht16k33.set_dimming(Dimming::BRIGHTNESS_MAX).unwrap(); i2c = ht16k33.destroy(); i2c.done(); } #[test] fn set_led() { let expectations = [I2cTransaction::write(ADDRESS, vec![1u8, 0b1000_0000])]; let mut i2c = I2cMock::new(&expectations); let mut ht16k33 = HT16K33::new(i2c, ADDRESS); ht16k33 .set_led(LedLocation::new(1, 7).unwrap(), true) .unwrap(); i2c = ht16k33.destroy(); i2c.done(); } #[test] fn write_display_buffer() { let mut write_buffer = vec![super::DisplayDataAddress::ROW_0.bits()]; write_buffer.extend([0; super::ROWS_SIZE].iter().cloned()); let expectations = [I2cTransaction::write(ADDRESS, write_buffer)]; let mut i2c = I2cMock::new(&expectations); let mut ht16k33 = HT16K33::new(i2c, ADDRESS); ht16k33.write_display_buffer().unwrap(); i2c = ht16k33.destroy(); i2c.done(); } #[test] fn read_display_buffer() { let mut read_buffer = vec![0; super::ROWS_SIZE]; read_buffer[1] = 0b0000_0010; read_buffer[15] = 0b0000_0010; let expectations = [I2cTransaction::write_read( ADDRESS, vec![super::DisplayDataAddress::ROW_0.bits()], read_buffer, )]; let mut i2c = I2cMock::new(&expectations); let mut ht16k33 = HT16K33::new(i2c, ADDRESS); ht16k33.read_display_buffer().unwrap(); let &buffer = ht16k33.display_buffer(); for value in 0..buffer.len() { match value { 1 | 15 => assert_eq!(buffer[value].bits(), 0b0000_0010), _ => assert_eq!(buffer[value].bits(), 0), } } i2c = ht16k33.destroy(); i2c.done(); } }