Merge pull request #6 from pbert519/optimize_memory_usage

Memory Management Improvements
pbert519 · Jun 19, 2024 · f190511 · f190511
2 parents 15d615f + 96c4a00
commit f190511
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Showing 8 changed files with 246 additions and 145 deletions.
diff --git a/Cargo.toml b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "it8951"
-version = "0.3.0"
+version = "0.4.0"
 edition = "2021"
 license = "MIT"
 description = "A IT8951 E-Paper driver"

diff --git a/README.md b/README.md
@@ -3,9 +3,29 @@
 This crate is mainly developed for the waveshare 7.8" epaper display using spi:
 https://www.waveshare.com/wiki/7.8inch_e-Paper_HAT
 The driver uses the embedded_hal traits as hardware abstraction layer.
-This driver can be used with the embedded graphics trait.
+This driver can be used with the embedded graphics trait, currently only supporing Gray4 (16bit grayscale).
 
 ## Details
-- IT8951 has a image load engine which can convert pixel data before storing it in the local frame buffer
+- IT8951 has a image load engine which can convert pixel data before storing it in the local frame  buffer.
 - It is possible to read and write the memory directly without using the image load engine
-- **Important** Data must be always aligned to 16bit words!
+- **Important** Data must be always aligned to 16bit words!
+- The crates uses the alloc feature to allocate memory on the heap:
+    - Firmware and LUT version string read from the controller
+    - Staging buffers to write pixel to the controller. The buffers are allocated as needed, but only one buffer at a time and with up to 1kByte of size.
+    - When reading controller memory a staging buffer with the size of of the requested data is created.
+
+
+## TODOs
+- Support Gray2 and Gray8 with embedded-graphics
+- Support display engine fill area
+- Support display engine 1 bit per pixel mode
+- Support static buffer allocations
+
+## Changelog
+
+### 0.4.0
+- **Public API** `new` expects a `Config` parameter to set timeout and buffer size. Default is implemented with timeouts of 15s and buffer size is 1024 Bytes.    
+- Buffer data type changed from u16 to u8
+    - **Public API**: `load_image_area`, `load_image`, and `memory_burst_write` functions are now using u8 as buffer type
+    - Memory usage is reduced by half (1kByte max. instead of 2kByte)
+- **Behavior** Calling `init` no longer clears the eink display. Instead call `reset` directly.
diff --git a/examples/esp32/src/main.rs b/examples/esp32/src/main.rs
@@ -2,6 +2,7 @@ use esp_idf_hal::{delay::Ets, gpio::PinDriver, prelude::*, spi::*};
 use esp_idf_sys as _; // If using the `binstart` feature of `esp-idf-sys`, always keep this module imported
 use it8951::{interface::*, *};
 use embedded_graphics::{prelude::*, primitives::{Rectangle, PrimitiveStyle}, pixelcolor::Gray4};
+use it8951::Config;
 
 fn main() -> ! {
     // Bind the log crate to the ESP Logging facilities
@@ -33,7 +34,7 @@ fn main() -> ! {
         reset,
         Ets,
     );
-    let mut epd = IT8951::new(display_interface).init(1605).unwrap();
+    let mut epd = IT8951::new(display_interface, Config::default()).init(1605).unwrap();
 
     log::info!("Initialized display: {:?}", epd.get_dev_info());
 

diff --git a/examples/test_eink.rs b/examples/test_eink.rs
@@ -1,3 +1,4 @@
+use it8951::Config;
 use linux_embedded_hal::gpio_cdev::{Chip, LineRequestFlags};
 use linux_embedded_hal::spidev::{SpiModeFlags, SpidevOptions};
 use linux_embedded_hal::{CdevPin, Delay, SpidevDevice};
@@ -34,7 +35,9 @@ fn main() -> Result<(), Box<dyn Error>> {
     let busy = CdevPin::new(busy_input_handle)?;
 
     let driver = it8951::interface::IT8951SPIInterface::new(spi, busy, rst, Delay);
-    let mut epd = it8951::IT8951::new(driver).init(1670).unwrap();
+    let mut epd = it8951::IT8951::new(driver, Config::default())
+        .init(1670)
+        .unwrap();
 
     println!(
         "Reset and initalized E-Ink Display: \n\r {:?}",

diff --git a/src/area_serializer.rs b/src/area_serializer.rs
@@ -9,21 +9,17 @@ use embedded_graphics_core::{
 pub struct AreaSerializer {
     area: Rectangle,
     rows_per_step: usize,
-    buffer: Vec<u16>,
+    buffer: Vec<u8>,
 }
 
 impl AreaSerializer {
-    pub fn new(area: Rectangle, color: Gray4) -> Self {
-        let max_entries: usize = 512; // 1 KByte
-
-        Self::with_buffer_size(area, color, max_entries)
-    }
-    pub fn with_buffer_size(area: Rectangle, color: Gray4, buffer_size: usize) -> Self {
-        let raw_color: u16 = color.luma() as u16;
-        let data_entry = raw_color << 12 | raw_color << 8 | raw_color << 4 | raw_color;
+    pub fn new(area: Rectangle, color: Gray4, buffer_size: usize) -> Self {
+        let raw_color = color.luma();
+        let data_entry = raw_color << 4 | raw_color;
 
+        assert!(buffer_size % 2 == 0, "Buffer size must be aligned to u16");
         // calculate the buffer size
-        let entries_per_row = get_entires_per_row(area) as usize;
+        let entries_per_row = get_entires_per_row(area) as usize * 2; // convert length from u16 to u8
         let rows_per_step = (buffer_size / entries_per_row).min(area.size.height as usize);
         assert!(rows_per_step > 0, "Buffer size to small for one row");
         let buffer = vec![data_entry; entries_per_row * rows_per_step];
@@ -50,7 +46,7 @@ impl<'a> AreaSerializerIterator<'a> {
 }
 
 impl<'a> Iterator for AreaSerializerIterator<'a> {
-    type Item = (AreaImgInfo, &'a [u16]);
+    type Item = (AreaImgInfo, &'a [u8]);
 
     fn next(&mut self) -> Option<Self::Item> {
         let area_height = self.area_serializer.area.size.height;
@@ -97,7 +93,11 @@ mod tests {
                 height: 1,
             },
         };
-        let area_s = AreaSerializer::new(area.intersection(&BOUNDING_BOX_DEFAULT), Gray4::new(0xA));
+        let area_s = AreaSerializer::new(
+            area.intersection(&BOUNDING_BOX_DEFAULT),
+            Gray4::new(0xA),
+            1024,
+        );
         let mut s = AreaSerializerIterator::new(&area_s);
         assert_eq!(
             s.next(),
@@ -108,7 +108,7 @@ mod tests {
                     area_w: 1,
                     area_h: 1
                 },
-                [0xAAAAu16].as_slice()
+                [0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(s.next(), None);
@@ -124,7 +124,11 @@ mod tests {
                 height: 1,
             },
         };
-        let area_s = AreaSerializer::new(area.intersection(&BOUNDING_BOX_DEFAULT), Gray4::new(0xA));
+        let area_s = AreaSerializer::new(
+            area.intersection(&BOUNDING_BOX_DEFAULT),
+            Gray4::new(0xA),
+            1024,
+        );
         let mut s = AreaSerializerIterator::new(&area_s);
         assert_eq!(
             s.next(),
@@ -135,7 +139,7 @@ mod tests {
                     area_w: 1,
                     area_h: 1
                 },
-                [0xAAAAu16].as_slice()
+                [0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(s.next(), None);
@@ -150,7 +154,11 @@ mod tests {
                 height: 1,
             },
         };
-        let area_s = AreaSerializer::new(area.intersection(&BOUNDING_BOX_DEFAULT), Gray4::new(0xA));
+        let area_s = AreaSerializer::new(
+            area.intersection(&BOUNDING_BOX_DEFAULT),
+            Gray4::new(0xA),
+            1024,
+        );
         let mut s = AreaSerializerIterator::new(&area_s);
         assert_eq!(
             s.next(),
@@ -161,7 +169,7 @@ mod tests {
                     area_w: 1,
                     area_h: 1
                 },
-                [0xAAAAu16].as_slice()
+                [0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(s.next(), None);
@@ -176,7 +184,11 @@ mod tests {
                 height: 1,
             },
         };
-        let area_s = AreaSerializer::new(area.intersection(&BOUNDING_BOX_DEFAULT), Gray4::new(0xA));
+        let area_s = AreaSerializer::new(
+            area.intersection(&BOUNDING_BOX_DEFAULT),
+            Gray4::new(0xA),
+            1024,
+        );
         let mut s = AreaSerializerIterator::new(&area_s);
         assert_eq!(
             s.next(),
@@ -187,7 +199,7 @@ mod tests {
                     area_w: 1,
                     area_h: 1
                 },
-                [0xAAAAu16].as_slice()
+                [0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(s.next(), None);
@@ -203,7 +215,11 @@ mod tests {
                 height: 1,
             },
         };
-        let area_s = AreaSerializer::new(area.intersection(&BOUNDING_BOX_DEFAULT), Gray4::new(0xA));
+        let area_s = AreaSerializer::new(
+            area.intersection(&BOUNDING_BOX_DEFAULT),
+            Gray4::new(0xA),
+            1024,
+        );
         let mut s = AreaSerializerIterator::new(&area_s);
 
         assert_eq!(
@@ -215,7 +231,7 @@ mod tests {
                     area_w: 4,
                     area_h: 1
                 },
-                [0xAAAAu16].as_slice()
+                [0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(s.next(), None);
@@ -231,7 +247,11 @@ mod tests {
                 height: 1,
             },
         };
-        let area_s = AreaSerializer::new(area.intersection(&BOUNDING_BOX_DEFAULT), Gray4::new(0xA));
+        let area_s = AreaSerializer::new(
+            area.intersection(&BOUNDING_BOX_DEFAULT),
+            Gray4::new(0xA),
+            1024,
+        );
         let mut s = AreaSerializerIterator::new(&area_s);
         assert_eq!(
             s.next(),
@@ -242,7 +262,7 @@ mod tests {
                     area_w: 3,
                     area_h: 1
                 },
-                [0xAAAAu16, 0xAAAAu16].as_slice()
+                [0xAA, 0xAA, 0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(s.next(), None);
@@ -258,11 +278,8 @@ mod tests {
                 height: 2,
             },
         };
-        let area_s = AreaSerializer::with_buffer_size(
-            area.intersection(&BOUNDING_BOX_DEFAULT),
-            Gray4::new(0xA),
-            1,
-        );
+        let area_s =
+            AreaSerializer::new(area.intersection(&BOUNDING_BOX_DEFAULT), Gray4::new(0xA), 2);
         let mut s = AreaSerializerIterator::new(&area_s);
         assert_eq!(
             s.next(),
@@ -273,7 +290,7 @@ mod tests {
                     area_w: 4,
                     area_h: 1
                 },
-                [0xAAAAu16].as_slice()
+                [0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(
@@ -285,7 +302,7 @@ mod tests {
                     area_w: 4,
                     area_h: 1
                 },
-                [0xAAAAu16].as_slice()
+                [0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(s.next(), None);
@@ -301,11 +318,8 @@ mod tests {
                 height: 2,
             },
         };
-        let area_s = AreaSerializer::with_buffer_size(
-            area.intersection(&BOUNDING_BOX_DEFAULT),
-            Gray4::new(0xA),
-            2,
-        );
+        let area_s =
+            AreaSerializer::new(area.intersection(&BOUNDING_BOX_DEFAULT), Gray4::new(0xA), 4);
         let mut s = AreaSerializerIterator::new(&area_s);
         assert_eq!(
             s.next(),
@@ -316,7 +330,7 @@ mod tests {
                     area_w: 3,
                     area_h: 1
                 },
-                [0xAAAAu16, 0xAAAAu16].as_slice()
+                [0xAA, 0xAA, 0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(
@@ -328,7 +342,7 @@ mod tests {
                     area_w: 3,
                     area_h: 1
                 },
-                [0xAAAAu16, 0xAAAAu16].as_slice()
+                [0xAA, 0xAA, 0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(s.next(), None);
@@ -344,7 +358,11 @@ mod tests {
                 height: 2,
             },
         };
-        let area_s = AreaSerializer::new(area.intersection(&BOUNDING_BOX_DEFAULT), Gray4::new(0xA));
+        let area_s = AreaSerializer::new(
+            area.intersection(&BOUNDING_BOX_DEFAULT),
+            Gray4::new(0xA),
+            1024,
+        );
         let mut s = AreaSerializerIterator::new(&area_s);
         assert_eq!(
             s.next(),
@@ -355,7 +373,7 @@ mod tests {
                     area_w: 4,
                     area_h: 2
                 },
-                [0xAAAAu16, 0xAAAAu16].as_slice()
+                [0xAA, 0xAA, 0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(s.next(), None);
@@ -371,7 +389,11 @@ mod tests {
                 height: 2,
             },
         };
-        let area_s = AreaSerializer::new(area.intersection(&BOUNDING_BOX_DEFAULT), Gray4::new(0xA));
+        let area_s = AreaSerializer::new(
+            area.intersection(&BOUNDING_BOX_DEFAULT),
+            Gray4::new(0xA),
+            1024,
+        );
         let mut s = AreaSerializerIterator::new(&area_s);
         assert_eq!(
             s.next(),
@@ -382,7 +404,7 @@ mod tests {
                     area_w: 3,
                     area_h: 2
                 },
-                [0xAAAAu16, 0xAAAAu16, 0xAAAAu16, 0xAAAAu16].as_slice()
+                [0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(s.next(), None);
@@ -398,7 +420,11 @@ mod tests {
                 height: 2,
             },
         };
-        let area_s = AreaSerializer::new(area.intersection(&BOUNDING_BOX_DEFAULT), Gray4::new(0xA));
+        let area_s = AreaSerializer::new(
+            area.intersection(&BOUNDING_BOX_DEFAULT),
+            Gray4::new(0xA),
+            1024,
+        );
         let mut s = AreaSerializerIterator::new(&area_s);
         assert_eq!(
             s.next(),
@@ -409,7 +435,7 @@ mod tests {
                     area_w: 2,
                     area_h: 1
                 },
-                [0xAAAAu16].as_slice()
+                [0xAA, 0xAA].as_slice()
             ))
         );
         assert_eq!(s.next(), None);