feat(buf): implement SoftSerial traits for HalfDuplexSerial with RingBuffer

src/lib.rs

@@ -14,6 +14,8 @@ use avr_device::asm::delay_cycles;
 
 use static_pins::StaticPinOps;
 
+mod structures;
+
 pub type PollResult = Result<(), PollError>;
 pub type ReadByteResult = Result<u8, CorruptedData>;
 pub type CorruptedData = (u8, u8);
@@ -107,100 +109,112 @@ pub trait SoftSerialWriter<P, T>
 where
     P: PinOps + StaticPinOps,
 {
-    #[inline(never)]
+    fn write_byte(&self, data: u8);
-    fn write_byte(&self, data: u8) {
-        let (mut data, mut parity_bit) = (data, 0);
-
-        for _ in 0..8 {
-            if data & MSB == 0 {
-                P::set_high();
-                parity_bit ^= 0;
-            } else {
-                P::set_low();
-                parity_bit ^= 1;
-            }
-
-            delay_us(SERIAL_DELAY);
-
-            data <<= 1;
-        }
-
-        // Hamming code and CRC are very weightful and slow, so I use simple parity check
-
-        if parity_bit == 0 {
-            P::set_high();
-        } else {
-            P::set_low();
-        }
-
-        delay_us(SERIAL_DELAY);
-    }
-
     fn write_bytes(&self, transmit_data: T);
 }
 
-impl<P> SoftSerialWriter<P, &[u8]> for HalfDuplexSerial<P>
-where
-    P: PinOps + StaticPinOps,
-{
-    fn write_bytes(&self, transmit_data: &[u8]) {
-        for byte in transmit_data {
-            self.write_byte(*byte);
-            self.sync_transmitter();
-        }
-    }
-}
-
 pub trait SoftSerialReader<P, T>
 where
     P: PinOps + StaticPinOps,
 {
-    #[inline(never)]
+    fn read_byte(&self) -> ReadByteResult;
-    fn read_byte(&self) -> ReadByteResult {
+    fn read_bytes(&self, recieve_data: T);
-        let (mut data, mut reciever_parity_bit) = (0, 0);
+}
 
-        delay_cycles(FIRST_ENTRY_READING);
+#[inline(always)]
-        for _ in 0..8 {
+pub(crate) fn _priv_read_byte<P: PinOps + StaticPinOps>() -> ReadByteResult {
-            delay_us(FIRST_HALF_SERIAL_DELAY);
+    let (mut data, mut reciever_parity_bit) = (0, 0);
-
-            data <<= 1;
-
-            if P::is_low() {
-                data |= 1;
-                reciever_parity_bit ^= 1;
-            } else {
-                data |= 0;
-                reciever_parity_bit ^= 0;
-            }
-
-            delay_cycles(READING_ADJUST);
-            delay_us(SECOND_HALF_SERIAL_DELAY);
-        }
 
+    delay_cycles(FIRST_ENTRY_READING);
+    for _ in 0..8 {
         delay_us(FIRST_HALF_SERIAL_DELAY);
 
-        let transmitter_parity_bit = (P::read() >> P::PIN_NUM) & LSB;
+        data <<= 1;
+
+        if P::is_low() {
+            data |= 1;
+            reciever_parity_bit ^= 1;
+        } else {
+            data |= 0;
+            reciever_parity_bit ^= 0;
+        }
 
         delay_cycles(READING_ADJUST);
         delay_us(SECOND_HALF_SERIAL_DELAY);
-
-        if reciever_parity_bit == transmitter_parity_bit {
-            return Err((data, reciever_parity_bit));
-        }
-
-        Ok(data)
     }
 
-    fn read_bytes(&self, recieve_data: T);
+    delay_us(FIRST_HALF_SERIAL_DELAY);
+
+    let transmitter_parity_bit = (P::read() >> P::PIN_NUM) & LSB;
+
+    delay_cycles(READING_ADJUST);
+    delay_us(SECOND_HALF_SERIAL_DELAY);
+
+    if reciever_parity_bit == transmitter_parity_bit {
+        return Err((data, reciever_parity_bit));
+    }
+
+    Ok(data)
+}
+
+#[inline(always)]
+pub(crate) fn _priv_write_bytes<P: PinOps + StaticPinOps>(data: u8) {
+    let (mut data, mut parity_bit) = (data, 0);
+
+    for _ in 0..8 {
+        if data & MSB == 0 {
+            P::set_high();
+            parity_bit ^= 0;
+        } else {
+            P::set_low();
+            parity_bit ^= 1;
+        }
+
+        delay_us(SERIAL_DELAY);
+
+        data <<= 1;
+    }
+
+    // Hamming code and CRC are very weightful and slow, so I use simple parity check
+
+    if parity_bit == 0 {
+        P::set_high();
+    } else {
+        P::set_low();
+    }
+
+    delay_us(SERIAL_DELAY);
+}
+
+impl<P> SoftSerialWriter<P, &[u8]> for HalfDuplexSerial<P>
+where
+    P: PinOps + StaticPinOps,
+{
+    #[inline(never)]
+    fn write_byte(&self, data: u8) {
+        _priv_write_bytes::<P>(data);
+    }
+
+    fn write_bytes(&self, transmit_data: &[u8]) {
+        for byte in transmit_data {
+            <Self as SoftSerialWriter<P, &[u8]>>::write_byte(self, *byte);
+            self.sync_transmitter();
+        }
+    }
 }
 
 impl<P> SoftSerialReader<P, &mut [u8]> for HalfDuplexSerial<P>
 where
     P: PinOps + StaticPinOps,
 {
+    #[inline(never)]
+    fn read_byte(&self) -> ReadByteResult {
+        _priv_read_byte::<P>()
+    }
+
     fn read_bytes(&self, recieve_data: &mut [u8]) {
         for byte in recieve_data {
-            if let Ok(data) = self.read_byte() {
+            if let Ok(data) = <Self as SoftSerialReader<P, &mut [u8]>>::read_byte(self) {
                 *byte = data;
             }
             self.sync_reciever();

src/structures/mod.rs

@@ -0,0 +1 @@
+pub mod ring_buffer;

src/structures/ring_buffer.rs

@@ -0,0 +1,148 @@
+// Thanks to Low Byte Productions, I like this channel.
+// Youtube: https://www.youtube.com/watch?v=uIJnATS9j_0
+
+use arduino_hal::port::PinOps;
+use static_pins::StaticPinOps;
+
+use crate::{HalfDuplexSerial, SoftSerialReader, SoftSerialWriter};
+
+#[derive(Debug, Clone, Copy)]
+pub struct RingBuffer<const N: usize> {
+    buf: [u8; N],
+    mask: usize,
+    head: usize,
+    tail: usize,
+}
+
+impl<const N: usize> RingBuffer<N> {
+    #[inline]
+    pub const fn new() -> Self {
+        if N.is_power_of_two() {
+            RingBuffer {
+                buf: [0; N],
+                mask: N - 1,
+                head: 0,
+                tail: 0,
+            }
+        } else {
+            panic!("Buffer capacity isn't power of two");
+        }
+    }
+
+    #[inline(always)]
+    pub fn get_buffer(&self) -> &[u8] {
+        &self.buf
+    }
+
+    #[inline(always)]
+    pub fn is_empty(&self) -> bool {
+        self.head == self.tail
+    }
+
+    #[inline(always)]
+    pub fn is_full(&self) -> bool {
+        (self.head + 1) & self.mask == self.tail
+    }
+
+    #[inline(always)]
+    pub fn capacity(&self) -> usize {
+        N
+    }
+
+    #[inline(always)]
+    pub fn len(&self) -> usize {
+        self.head.overflowing_sub(self.tail).0 & self.mask
+    }
+
+    #[inline(always)]
+    pub fn clear(&mut self) {
+        self.buf = [0; N];
+        self.head = 0;
+        self.tail = 0;
+    }
+
+    #[inline(always)]
+    pub fn push(&mut self, value: u8) -> Option<()> {
+        let (head, tail) = (self.head, self.tail);
+        let next_head = (head + 1) & self.mask;
+
+        if next_head == tail {
+            return None;
+        }
+
+        self.buf[head] = value;
+        self.head = next_head;
+
+        Some(())
+    }
+
+    #[inline(always)]
+    pub fn pop(&mut self) -> Option<u8> {
+        let (head, mut tail) = (self.head, self.tail);
+
+        if head == tail {
+            return None;
+        }
+
+        let value = self.buf[tail];
+        tail = (tail + 1) & self.mask;
+        self.tail = tail;
+
+        Some(value)
+    }
+}
+
+impl<const N: usize> Iterator for RingBuffer<N> {
+    type Item = u8;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.pop()
+    }
+}
+
+impl<const N: usize, P> SoftSerialWriter<P, &mut RingBuffer<N>> for HalfDuplexSerial<P>
+where
+    P: PinOps + StaticPinOps,
+{
+    #[inline(never)]
+    fn write_byte(&self, data: u8) {
+        crate::_priv_write_bytes::<P>(data);
+    }
+
+    fn write_bytes(&self, transmit_data: &mut RingBuffer<N>) {
+        self.sync_transmitter();
+        <Self as SoftSerialWriter<P, &mut RingBuffer<N>>>::write_byte(self, N as u8);
+
+        for _ in 0..N {
+            let byte = transmit_data.pop().unwrap_or(0);
+            self.sync_transmitter();
+            <Self as SoftSerialWriter<P, &mut RingBuffer<N>>>::write_byte(self, byte);
+        }
+    }
+}
+
+impl<const N: usize, P> SoftSerialReader<P, &mut RingBuffer<N>> for HalfDuplexSerial<P>
+where
+    P: PinOps + StaticPinOps,
+{
+    #[inline(never)]
+    fn read_byte(&self) -> crate::ReadByteResult {
+        crate::_priv_read_byte::<P>()
+    }
+
+    fn read_bytes(&self, recieve_data: &mut RingBuffer<N>) {
+        self.sync_reciever();
+        let byte = <Self as SoftSerialReader<P, &mut RingBuffer<N>>>::read_byte(self);
+
+        if let Ok(len) = byte {
+            for _ in 0..len {
+                self.sync_reciever();
+
+                if let Ok(byte) = <Self as SoftSerialReader<P, &mut RingBuffer<N>>>::read_byte(self)
+                {
+                    recieve_data.push(byte).unwrap_or(());
+                }
+            }
+        }
+    }
+}