From da02f35df636c47869db51af547b7862c46c6a6a Mon Sep 17 00:00:00 2001
From: Stephen D <webmaster@scd31.com>
Date: Sat, 4 Nov 2023 18:45:33 -0300
Subject: [PATCH] wip moving to borrowed ram
---
src/internal_state.rs | 6 +--
src/lib.rs | 86 ++++++++++++++++++++++++++-----------------
src/rx.rs | 14 ++++---
3 files changed, 65 insertions(+), 41 deletions(-)
diff --git a/src/internal_state.rs b/src/internal_state.rs
index 3bdb772..ef64e3b 100644
--- a/src/internal_state.rs
+++ b/src/internal_state.rs
@@ -1,15 +1,15 @@
// Tracks the state of our instance, *not* the state of the radio.
#[derive(Debug)]
-pub enum InternalState<const PACKET_LEN: usize> {
+pub enum InternalState<'a, const PACKET_LEN: usize> {
Idle,
Rx {
- data: [u8; PACKET_LEN],
+ data: &'a mut [u8; PACKET_LEN],
i: usize,
received: bool,
rssi: Option<f64>,
},
Tx {
- data: [u8; PACKET_LEN],
+ data: &'a [u8],
i: usize,
len: usize,
},
diff --git a/src/lib.rs b/src/lib.rs
index 187f549..d9b2afa 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -22,20 +22,21 @@ use state::State;
use crate::internal_radio::InternalRadio;
-pub struct Rf4463<const MAX_PACKET_LEN: usize, Spi, SdnPin, CsPin, Delay> {
+pub struct Rf4463<'a, const MAX_PACKET_LEN: usize, Spi, SdnPin, CsPin, Delay> {
radio: InternalRadio<Spi, SdnPin, CsPin, Delay>,
- state: InternalState<MAX_PACKET_LEN>,
+ state: InternalState<'a, MAX_PACKET_LEN>,
rx_forever: bool,
channel: u8,
}
impl<
+ 'a,
const MAX_PACKET_LEN: usize,
Spi: Transfer<u8>,
SdnPin: OutputPin<Error = Infallible>,
CsPin: OutputPin<Error = Infallible>,
Delay: DelayUs<u16>,
- > Rf4463<MAX_PACKET_LEN, Spi, SdnPin, CsPin, Delay>
+ > Rf4463<'a, MAX_PACKET_LEN, Spi, SdnPin, CsPin, Delay>
where
Spi::Error: Debug,
{
@@ -91,14 +92,19 @@ where
}
// Len is none when using a variable-length packet
- pub fn start_rx(&mut self, len: Option<usize>, rx_forever: bool) -> Result<(), Spi::Error> {
+ pub fn start_rx(
+ &mut self,
+ buf: &'a mut [u8; MAX_PACKET_LEN],
+ len: Option<usize>,
+ rx_forever: bool,
+ ) -> Result<(), Spi::Error> {
self.radio.clear_fifo()?;
self.radio.clear_ph_and_modem_interrupts()?;
let len = len.unwrap_or(0);
self.state = InternalState::Rx {
- data: [0; MAX_PACKET_LEN],
+ data: buf,
i: 0,
received: false,
rssi: None,
@@ -124,44 +130,58 @@ where
Ok(())
}
- pub fn finish_rx(&mut self) -> Result<Option<RxPacket<MAX_PACKET_LEN>>, Spi::Error> {
- let pkt = match self.state {
+ /// Panics if rx_forever is true and new_buf is None
+ pub fn finish_rx(
+ &mut self,
+ new_buf: Option<&'a mut [u8; MAX_PACKET_LEN]>,
+ ) -> Result<Option<RxPacket<MAX_PACKET_LEN>>, Spi::Error> {
+ let (set_idle, ret) = match &mut self.state {
InternalState::Rx {
data,
received,
i,
rssi,
- } if received => {
- let rssi = match rssi {
+ } if *received => {
+ let ret_rssi = match *rssi {
Some(x) => x,
- None => self.get_rssi()?,
+ None => self.radio.get_rssi()?,
};
- let ret = Some(RxPacket::new(data, i, rssi));
+ let ret = if self.rx_forever {
+ let new_buf = new_buf.expect("rx_forever=true and no replacement buffer given");
- if self.rx_forever {
self.radio.clear_ph_and_modem_interrupts()?;
- self.state = InternalState::Rx {
- data: [0; MAX_PACKET_LEN],
- i: 0,
- received: false,
- rssi: None,
- };
+ core::mem::swap(new_buf, data);
+ *i = 0;
+ *received = false;
+ *rssi = None;
+
+ (false, Some(RxPacket::new(new_buf, *i, ret_rssi)))
} else {
- self.state = InternalState::Idle;
- }
+ (true, Some(RxPacket::new(data, *i, ret_rssi)))
+ };
ret
}
- _ => None,
+ _ => (false, None),
};
- Ok(pkt)
+ if set_idle {
+ self.state = InternalState::Idle;
+ }
+
+ Ok(ret)
}
- pub fn start_tx(&mut self, data: &[u8]) -> Result<(), TxError<Spi::Error>> {
+ /// Panics if data length is > 8191
+ pub fn start_tx(&mut self, data: &'a [u8]) -> Result<(), TxError<Spi::Error>> {
+ assert!(
+ MAX_PACKET_LEN < 8192,
+ "Packet length cannot be above 8191 bytes"
+ );
+
let len = data.len();
if len > MAX_PACKET_LEN {
return Err(TxError::TooMuchData);
@@ -194,13 +214,7 @@ where
])
.txe()?;
- let mut padded_data = [0; MAX_PACKET_LEN];
- padded_data[0..len].copy_from_slice(data);
- self.state = InternalState::Tx {
- data: padded_data,
- i,
- len,
- };
+ self.state = InternalState::Tx { data, i, len };
Ok(())
}
@@ -288,12 +302,12 @@ where
fn tx_step(&mut self) -> Result<(), TransferError<Spi::Error>> {
let (data, i) = match &mut self.state {
- InternalState::Tx { data, i, len } => (&mut data[0..*len], i),
+ InternalState::Tx { data, i, len } => (&data[0..*len], i),
_ => return Ok(()),
};
// only look at the slice we haven't sent yet
- let data = &mut data[*i..];
+ let data = &data[*i..];
let len: usize = self.radio.tx_fifo_space().te()?.into();
let len = len.min(data.len());
@@ -301,13 +315,19 @@ where
return Ok(());
}
+ // we need a mutable reference on data for our transfer function
+ // so we copy that data into a temporary buffer
+ const FIFO_BUFFER_LEN: usize = 129;
+ let mut buf = [0; FIFO_BUFFER_LEN];
+ buf[..len].copy_from_slice(&data[..len]);
+
if self.radio.fifo_underflow_pending().te()? {
return Err(TransferError::FifoOverflow);
}
self.radio.with_cs(|s| {
s.spi_transfer_byte(WRITE_TX_FIFO).te()?;
- s.spi.transfer(&mut data[0..len]).te()?;
+ s.spi.transfer(&mut buf[0..len]).te()?;
Ok(())
})?;
diff --git a/src/rx.rs b/src/rx.rs
index 7677257..e7f99d6 100644
--- a/src/rx.rs
+++ b/src/rx.rs
@@ -1,12 +1,12 @@
-#[derive(Debug, Clone)]
-pub struct RxPacket<const N: usize> {
- data: [u8; N],
+#[derive(Debug)]
+pub struct RxPacket<'a, const N: usize> {
+ data: &'a mut [u8; N],
i: usize,
rssi: f64,
}
-impl<const N: usize> RxPacket<N> {
- pub(crate) fn new(data: [u8; N], i: usize, rssi: f64) -> Self {
+impl<'a, const N: usize> RxPacket<'a, N> {
+ pub(crate) fn new(data: &'a mut [u8; N], i: usize, rssi: f64) -> Self {
Self { data, i, rssi }
}
@@ -17,4 +17,8 @@ impl<const N: usize> RxPacket<N> {
pub fn rssi(&self) -> f64 {
self.rssi
}
+
+ fn into_buf(self) -> &'a mut [u8; N] {
+ self.data
+ }
}
--
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