00b57bac55
Per keystroke, diff the new frame against the last shown one to find the changed row band and partial-refresh only those rows instead of all 272. E-paper update time scales with the gate rows driven, so a single edited text line refreshes far faster. Windowed in Y only (full width, both controllers), so the seam/mirroring logic is unchanged. Also drop the periodic full refresh to every 64 updates — the panel stays visually clean, so it's now mainly for longevity.
372 lines
14 KiB
Rust
372 lines
14 KiB
Rust
//! Thin SSD1683 driver for the GDEY0579T93 (792×272) e-paper panel.
|
||
//!
|
||
//! This panel is a *dual-controller* device: 792×272 exceeds one SSD1683's
|
||
//! 400×300 limit, so it is driven as a **master** (command offset `0x00`) +
|
||
//! **slave** (`0x80`) pair, with the framebuffer split between them. The
|
||
//! command sequences and RAM-window math are ported faithfully from GxEPD2's
|
||
//! `GxEPD2_579_GDEY0579T93` (Jean-Marc Zingg), itself based on the Good
|
||
//! Display factory demo. See `docs/v0.1-mvp-technical.md` (Spike 2) and
|
||
//! ADR-003.
|
||
//!
|
||
//! Capabilities: hardware reset, init, uniform fill, full-frame blit via an
|
||
//! `embedded-graphics` `DrawTarget` (`Frame`), full refresh (`display_frame`),
|
||
//! and partial refresh (`display_frame_partial`) — Spikes 2 and 5.
|
||
|
||
use embedded_graphics::pixelcolor::BinaryColor;
|
||
use embedded_graphics::prelude::*;
|
||
use esp_idf_svc::hal::delay::FreeRtos;
|
||
use esp_idf_svc::hal::gpio::{Input, Output, PinDriver};
|
||
use esp_idf_svc::hal::spi::{SpiBusDriver, SpiDriver};
|
||
use esp_idf_svc::sys::EspError;
|
||
|
||
pub const WIDTH: u16 = 792;
|
||
pub const HEIGHT: u16 = 272;
|
||
|
||
/// Each controller drives one half. SSD1683 X is byte-addressed; 396 px
|
||
/// rounds up to 50 bytes (400 px) of RAM width, full panel height (272 rows).
|
||
const CTRL_BYTES_W: usize = 50;
|
||
const CTRL_BYTES: usize = CTRL_BYTES_W * HEIGHT as usize; // 50 * 272 = 13600
|
||
|
||
/// Full-frame 1-bit framebuffer: 792 px = 99 bytes per row, MSB-first,
|
||
/// 1 = white, 0 = black (SSD16xx convention).
|
||
pub const FB_BYTES_W: usize = (WIDTH / 8) as usize; // 99
|
||
pub const FB_BYTES: usize = FB_BYTES_W * HEIGHT as usize; // 26928
|
||
|
||
/// In-memory 792×272 1-bit frame, drawable via `embedded-graphics`.
|
||
/// `BinaryColor::On` = black ink, `Off` = white paper.
|
||
pub struct Frame {
|
||
buf: Vec<u8>,
|
||
}
|
||
|
||
impl Frame {
|
||
pub fn new_white() -> Self {
|
||
Self { buf: vec![0xFF; FB_BYTES] }
|
||
}
|
||
|
||
#[allow(dead_code)] // symmetric with new_white; kept as part of the API
|
||
pub fn new_black() -> Self {
|
||
Self { buf: vec![0x00; FB_BYTES] }
|
||
}
|
||
|
||
pub fn bytes(&self) -> &[u8] {
|
||
&self.buf
|
||
}
|
||
}
|
||
|
||
impl OriginDimensions for Frame {
|
||
fn size(&self) -> Size {
|
||
Size::new(WIDTH as u32, HEIGHT as u32)
|
||
}
|
||
}
|
||
|
||
impl DrawTarget for Frame {
|
||
type Color = BinaryColor;
|
||
type Error = core::convert::Infallible;
|
||
|
||
fn draw_iter<I>(&mut self, pixels: I) -> Result<(), Self::Error>
|
||
where
|
||
I: IntoIterator<Item = Pixel<Self::Color>>,
|
||
{
|
||
for Pixel(p, color) in pixels {
|
||
if (0..WIDTH as i32).contains(&p.x) && (0..HEIGHT as i32).contains(&p.y) {
|
||
let idx = p.y as usize * FB_BYTES_W + p.x as usize / 8;
|
||
let bit = 0x80u8 >> (p.x % 8);
|
||
match color {
|
||
BinaryColor::On => self.buf[idx] &= !bit, // black ink
|
||
BinaryColor::Off => self.buf[idx] |= bit, // white paper
|
||
}
|
||
}
|
||
}
|
||
Ok(())
|
||
}
|
||
}
|
||
|
||
/// Max bytes per SPI transfer; matches the DMA size configured in `main`.
|
||
const SPI_CHUNK: usize = 4096;
|
||
|
||
pub struct Epd<'d> {
|
||
spi: SpiBusDriver<'d, SpiDriver<'d>>,
|
||
dc: PinDriver<'d, Output>,
|
||
rst: PinDriver<'d, Output>,
|
||
cs: PinDriver<'d, Output>,
|
||
busy: PinDriver<'d, Input>,
|
||
}
|
||
|
||
impl<'d> Epd<'d> {
|
||
pub fn new(
|
||
spi: SpiBusDriver<'d, SpiDriver<'d>>,
|
||
dc: PinDriver<'d, Output>,
|
||
rst: PinDriver<'d, Output>,
|
||
cs: PinDriver<'d, Output>,
|
||
busy: PinDriver<'d, Input>,
|
||
) -> Self {
|
||
Self { spi, dc, rst, cs, busy }
|
||
}
|
||
|
||
// ---- low-level SPI framing (DC low = command, DC high = data) ----
|
||
|
||
fn cmd(&mut self, c: u8) -> Result<(), EspError> {
|
||
self.dc.set_low()?;
|
||
self.cs.set_low()?;
|
||
self.spi.write(&[c])?;
|
||
self.cs.set_high()?;
|
||
Ok(())
|
||
}
|
||
|
||
fn data(&mut self, bytes: &[u8]) -> Result<(), EspError> {
|
||
self.dc.set_high()?;
|
||
self.cs.set_low()?;
|
||
for chunk in bytes.chunks(SPI_CHUNK) {
|
||
self.spi.write(chunk)?;
|
||
}
|
||
self.cs.set_high()?;
|
||
Ok(())
|
||
}
|
||
|
||
/// BUSY is active-HIGH on this panel (GxEPD2 constructs with `HIGH`).
|
||
fn wait_while_busy(&mut self, timeout_ms: u32) -> Result<(), EspError> {
|
||
let mut waited = 0;
|
||
while self.busy.is_high() {
|
||
FreeRtos::delay_ms(1);
|
||
waited += 1;
|
||
if waited >= timeout_ms {
|
||
log::warn!("EPD BUSY still high after {timeout_ms} ms — continuing");
|
||
break;
|
||
}
|
||
}
|
||
Ok(())
|
||
}
|
||
|
||
// ---- panel bring-up ----
|
||
|
||
/// Hardware reset (RST is active-low). ~20 ms pulses per GxEPD2 default.
|
||
pub fn reset(&mut self) -> Result<(), EspError> {
|
||
self.rst.set_high()?;
|
||
FreeRtos::delay_ms(20);
|
||
self.rst.set_low()?;
|
||
FreeRtos::delay_ms(20);
|
||
self.rst.set_high()?;
|
||
FreeRtos::delay_ms(20);
|
||
self.wait_while_busy(100)?;
|
||
Ok(())
|
||
}
|
||
|
||
/// Port of GxEPD2 `_InitDisplay` (B/W mode). The `0x20` master
|
||
/// activations load the temperature value and LUT.
|
||
pub fn init(&mut self) -> Result<(), EspError> {
|
||
self.cmd(0x12)?; // SWRESET
|
||
FreeRtos::delay_ms(10);
|
||
self.wait_while_busy(100)?;
|
||
self.cmd(0x18)?; // temperature sensor control
|
||
self.data(&[0x80])?; // internal sensor
|
||
self.cmd(0x22)?; // display update control 2
|
||
self.data(&[0xB1])?; // enable clock, load temp, load LUT (B/W), disable clock
|
||
self.cmd(0x20)?; // master activation
|
||
FreeRtos::delay_ms(10);
|
||
self.wait_while_busy(100)?;
|
||
self.cmd(0x1A)?; // write to temperature register
|
||
self.data(&[0x64, 0x00])?;
|
||
self.cmd(0x22)?;
|
||
self.data(&[0x91])?; // load temp, load LUT (B/W), disable clock
|
||
self.cmd(0x20)?;
|
||
FreeRtos::delay_ms(10);
|
||
self.wait_while_busy(100)?;
|
||
Ok(())
|
||
}
|
||
|
||
/// Port of GxEPD2 `_setPartialRamArea`. `target` is `0x00` (master) or
|
||
/// `0x80` (slave); `mode` selects X/Y increment/decrement (0x00–0x03).
|
||
fn set_ram_area(
|
||
&mut self,
|
||
x: u16,
|
||
y: u16,
|
||
w: u16,
|
||
h: u16,
|
||
mode: u8,
|
||
target: u8,
|
||
) -> Result<(), EspError> {
|
||
self.cmd(0x11 | target)?; // data entry mode
|
||
self.data(&[mode])?;
|
||
let xl = (x / 8) as u8;
|
||
let xh = ((x + w - 1) / 8) as u8;
|
||
let ys = [(y % 256) as u8, (y / 256) as u8];
|
||
let ye = [((y + h - 1) % 256) as u8, ((y + h - 1) / 256) as u8];
|
||
match mode {
|
||
0x03 => {
|
||
// X increment, Y increment
|
||
self.cmd(0x44 | target)?;
|
||
self.data(&[xl, xh])?;
|
||
self.cmd(0x45 | target)?;
|
||
self.data(&[ys[0], ys[1], ye[0], ye[1]])?;
|
||
self.cmd(0x4E | target)?;
|
||
self.data(&[xl])?;
|
||
self.cmd(0x4F | target)?;
|
||
self.data(&[ys[0], ys[1]])?;
|
||
}
|
||
0x02 => {
|
||
// X decrement, Y increment
|
||
self.cmd(0x44 | target)?;
|
||
self.data(&[xh, xl])?;
|
||
self.cmd(0x45 | target)?;
|
||
self.data(&[ys[0], ys[1], ye[0], ye[1]])?;
|
||
self.cmd(0x4E | target)?;
|
||
self.data(&[xh])?;
|
||
self.cmd(0x4F | target)?;
|
||
self.data(&[ys[0], ys[1]])?;
|
||
}
|
||
0x01 => {
|
||
// X increment, Y decrement
|
||
self.cmd(0x44 | target)?;
|
||
self.data(&[xl, xh])?;
|
||
self.cmd(0x45 | target)?;
|
||
self.data(&[ye[0], ye[1], ys[0], ys[1]])?;
|
||
self.cmd(0x4E | target)?;
|
||
self.data(&[xl])?;
|
||
self.cmd(0x4F | target)?;
|
||
self.data(&[ye[0], ye[1]])?;
|
||
}
|
||
_ => {
|
||
// 0x00: X decrement, Y decrement
|
||
self.cmd(0x44 | target)?;
|
||
self.data(&[xh, xl])?;
|
||
self.cmd(0x45 | target)?;
|
||
self.data(&[ye[0], ye[1], ys[0], ys[1]])?;
|
||
self.cmd(0x4E | target)?;
|
||
self.data(&[xh])?;
|
||
self.cmd(0x4F | target)?;
|
||
self.data(&[ye[0], ye[1]])?;
|
||
}
|
||
}
|
||
FreeRtos::delay_ms(2);
|
||
Ok(())
|
||
}
|
||
|
||
/// Fill one RAM bank (`0x24` current or `0x26` previous) on both
|
||
/// controllers with a constant byte. One clean full-coverage window per
|
||
/// controller (slave = left half `0x80`, master = right half `0x00`) —
|
||
/// simpler and more complete than GxEPD2's overlapping-window fill, which
|
||
/// only matters for a constant value anyway.
|
||
fn write_buffer(&mut self, command: u8, value: u8) -> Result<(), EspError> {
|
||
let buf = vec![value; CTRL_BYTES];
|
||
for target in [0x80u8, 0x00u8] {
|
||
self.set_ram_area(0, 0, 400, HEIGHT, 0x03, target)?;
|
||
self.cmd(command | target)?;
|
||
self.data(&buf)?;
|
||
}
|
||
Ok(())
|
||
}
|
||
|
||
/// Port of GxEPD2 `refresh(false)` → `_Update_Full` (fast full update).
|
||
fn update_full(&mut self) -> Result<(), EspError> {
|
||
self.set_ram_area(0, 0, WIDTH / 2, HEIGHT, 0x03, 0x80)?; // slave
|
||
self.set_ram_area(0, 0, WIDTH / 2, HEIGHT, 0x03, 0x00)?; // master
|
||
self.cmd(0x21)?; // display update control 1
|
||
self.data(&[0x40, 0x10])?; // bypass RED as 0, cascade
|
||
self.cmd(0x1A)?; // temperature register (fast full update)
|
||
self.data(&[0x64, 0x00])?;
|
||
self.cmd(0x22)?;
|
||
self.data(&[0xD7])?; // fast full update
|
||
self.cmd(0x20)?; // master activation
|
||
self.wait_while_busy(2500)?; // full_refresh_time ≈ 2200 ms
|
||
Ok(())
|
||
}
|
||
|
||
/// Port of GxEPD2 `_Update_Part` — the partial-update waveform. No full
|
||
/// flashing; only pixels that differ between the "previous" (`0x26`) and
|
||
/// "current" (`0x24`) banks transition. Much faster than a full refresh
|
||
/// but leaves faint ghosting that a periodic full refresh clears. Like
|
||
/// GxEPD2 for this dual-controller panel, the update covers the whole
|
||
/// panel (windowing isn't worthwhile — the waveform time dominates, not
|
||
/// the area).
|
||
/// `y0`/`h` restrict the update to a horizontal band of rows. E-paper
|
||
/// update time scales with the number of gate lines driven, so a narrow
|
||
/// band (one text line) is far faster than the whole panel — the win that
|
||
/// makes per-keystroke typing responsive. Full width is always driven
|
||
/// (both controllers), so the seam/mirroring logic is untouched.
|
||
fn update_part(&mut self, y0: u16, h: u16) -> Result<(), EspError> {
|
||
self.set_ram_area(0, y0, WIDTH / 2, h, 0x03, 0x80)?; // slave
|
||
self.set_ram_area(0, y0, WIDTH / 2, h, 0x03, 0x00)?; // master
|
||
self.cmd(0x3C)?; // border waveform control
|
||
self.data(&[0x80])?; // VCOM
|
||
self.cmd(0x21)?; // display update control 1
|
||
self.data(&[0x00, 0x10])?; // RED normal, cascade
|
||
self.cmd(0x22)?; // display update control 2
|
||
self.data(&[0xFF])?; // partial update
|
||
self.cmd(0x20)?; // master activation
|
||
self.wait_while_busy(2000)?; // partial is well under the full ~2.2 s
|
||
Ok(())
|
||
}
|
||
|
||
/// Fill the whole panel with one value and full-refresh.
|
||
/// `0xFF` = white, `0x00` = black. Port of GxEPD2 `clearScreen`.
|
||
pub fn clear_screen(&mut self, value: u8) -> Result<(), EspError> {
|
||
self.write_buffer(0x26, value)?; // previous
|
||
self.write_buffer(0x24, value)?; // current
|
||
self.update_full()?;
|
||
Ok(())
|
||
}
|
||
|
||
/// Blit rows `y0..y0+h` of a 792×272 framebuffer into one RAM bank on both
|
||
/// controllers. Port of GxEPD2 `_writeFromImage`, windowed in Y: slave gets
|
||
/// panel bytes 0..=49 of each row in X-increment mode; the master's sources
|
||
/// are wired mirrored, so it gets bytes 49..=98 in bitmap order while the
|
||
/// address counter walks RAM 49..=0 (mode 0x02). The seam byte 49
|
||
/// (px 392..399) lands on both; the 4 columns past each controller's 396
|
||
/// sources aren't wired. Pass `(0, HEIGHT)` for a full-frame blit.
|
||
fn write_frame_bank(&mut self, command: u8, fb: &[u8], y0: u16, h: u16) -> Result<(), EspError> {
|
||
let rows = y0 as usize..(y0 + h) as usize;
|
||
|
||
let mut buf = Vec::with_capacity(CTRL_BYTES_W * h as usize);
|
||
for y in rows.clone() {
|
||
let row = &fb[y * FB_BYTES_W..(y + 1) * FB_BYTES_W];
|
||
buf.extend_from_slice(&row[..CTRL_BYTES_W]);
|
||
}
|
||
self.set_ram_area(0, y0, WIDTH / 2, h, 0x03, 0x80)?; // slave
|
||
self.cmd(command | 0x80)?;
|
||
self.data(&buf)?;
|
||
|
||
buf.clear();
|
||
for y in rows {
|
||
let row = &fb[y * FB_BYTES_W..(y + 1) * FB_BYTES_W];
|
||
buf.extend_from_slice(&row[FB_BYTES_W - CTRL_BYTES_W..]);
|
||
}
|
||
self.set_ram_area(0, y0, WIDTH / 2, h, 0x02, 0x00)?; // master
|
||
self.cmd(command)?;
|
||
self.data(&buf)?;
|
||
Ok(())
|
||
}
|
||
|
||
/// Show a full 792×272 framebuffer (`FB_BYTES` long) with a full
|
||
/// refresh. Writes both RAM banks so the next differential update has a
|
||
/// consistent "previous" image.
|
||
pub fn display_frame(&mut self, fb: &[u8]) -> Result<(), EspError> {
|
||
assert_eq!(fb.len(), FB_BYTES, "framebuffer must be 99 x 272 bytes");
|
||
self.write_frame_bank(0x26, fb, 0, HEIGHT)?; // previous
|
||
self.write_frame_bank(0x24, fb, 0, HEIGHT)?; // current
|
||
self.update_full()?;
|
||
Ok(())
|
||
}
|
||
|
||
/// Partial-refresh only rows `y0..y0+h` of the panel from a full
|
||
/// framebuffer — the fast per-keystroke path (pass `(0, HEIGHT)` for the
|
||
/// whole panel). Requires the `0x26` (previous) bank to already hold the
|
||
/// on-screen image for those rows — true after any `display_frame`,
|
||
/// `clear_screen`, or a prior partial covering them. Writes the new rows to
|
||
/// `0x24`, runs the partial waveform over just that band, then syncs `0x26`
|
||
/// so the next partial has a correct baseline. `fb` is always the full
|
||
/// frame; only the given rows are used.
|
||
pub fn display_frame_partial_window(
|
||
&mut self,
|
||
fb: &[u8],
|
||
y0: u16,
|
||
h: u16,
|
||
) -> Result<(), EspError> {
|
||
assert_eq!(fb.len(), FB_BYTES, "framebuffer must be 99 x 272 bytes");
|
||
assert!(h > 0 && y0 + h <= HEIGHT, "row window out of range");
|
||
self.write_frame_bank(0x24, fb, y0, h)?; // current = new
|
||
self.update_part(y0, h)?; // transition previous (0x26) -> current (0x24)
|
||
self.write_frame_bank(0x26, fb, y0, h)?; // previous = new, for next time
|
||
Ok(())
|
||
}
|
||
}
|