Rename + refector + CRC support

This commit is contained in:
Jonathan BAUDIN 2023-09-09 21:41:19 +02:00
parent 555911da16
commit 1186e8e888
5 changed files with 60 additions and 29 deletions

View file

@ -1,6 +1,6 @@
[package]
name = "dht-pio"
version = "0.1.0"
version = "0.2.0"
edition = "2021"
license = "MIT"

View file

@ -26,8 +26,8 @@ For the moment, the crates have only been tested on a Raspberry Pico.
## TODO
- [ ] Finish Readme
- [ ] Add CRC read
- [ ] Check CRC
- [x] Add CRC read
- [x] Check CRC
- [ ] DHT11 support
- [ ] Test DHT11
- [ ] Document code

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@ -29,8 +29,8 @@ Pour le moment le crates n'a été testé que sur un Raspberry Pico.
## TODO
- [ ] Finir le Readme
- [ ] Ajouter la lecture du CRC
- [ ] Vérifier le CRC
- [x] Ajouter la lecture du CRC
- [x] Vérifier le CRC
- [ ] Support du DHT11
- [ ] Tester DHT11
- [ ] Documenter le code

View file

@ -1,3 +1,4 @@
.define bit_to_recv 32
.program dht
; Clock must be set for 1µs per instruction
@ -15,7 +16,9 @@
wait 0 pin 0 ; Wait for low
wait 1 pin 0 ; wait for high
set x, 31 ; Set number bit to received (ignore CRC :( sorry )
set y, 4 ; set the number of byte to receive - 1
init_loop_data:
set x, 7 ; Set number bit to receive - 1
loop_data:
wait 0 pin 0 ; Wait for low
wait 1 pin 0 ; wait for high
@ -23,7 +26,10 @@
nop [29] ; wait for ~ 30 µS
in pins, 1 ; read the pin state and store bit value
push iffull noblock ; Push data if full
jmp x--, loop_data ; Run until read all bits
jmp x--, loop_data ; Run until read all bitsw
push ; send result
jmp y--, init_loop_data
push ; Push the last bytes

View file

@ -11,7 +11,7 @@ pub enum DhtError {
/// Timeout during communication.
Timeout,
/// CRC mismatch.
CrcMismatch,
CrcMismatch(u32, u32),
/// FIFO Read error
ReadError,
}
@ -22,14 +22,14 @@ pub struct DhtResult {
pub humidity: f32,
}
pub struct PicoDht<P: PIOExt, STI: StateMachineIndex> {
pub struct DhtPio<P: PIOExt, STI: StateMachineIndex> {
// sm: PicoStateMachine<P, STI>,
sm: StateMachine<(P, STI), Running>,
rx_fifo: Rx<(P, STI)>,
tx_fifo: Tx<(P, STI)>,
}
impl<P: PIOExt, STI: StateMachineIndex> PicoDht<P, STI> {
impl<P: PIOExt, STI: StateMachineIndex> DhtPio<P, STI> {
pub fn new<I: AnyPin<Function = P::PinFunction>>(
mut pio: rp2040_hal::pio::PIO<P>,
sm: UninitStateMachine<(P, STI)>,
@ -45,6 +45,7 @@ impl<P: PIOExt, STI: StateMachineIndex> PicoDht<P, STI> {
let (mut sm, rx, tx) = rp2040_hal::pio::PIOBuilder::from_program(installed)
.set_pins(pin.id().num, 1)
.clock_divisor_fixed_point(int, frac)
.push_threshold(32)
.build(sm);
sm.set_pindirs([(pin.id().num, rp2040_hal::pio::PinDir::Output)]);
@ -58,10 +59,22 @@ impl<P: PIOExt, STI: StateMachineIndex> PicoDht<P, STI> {
/// Read data from the sensor. This blocking function (for maximum timeout of 2 seconds).
pub fn read_data(&mut self, delay: &mut Delay) -> Result<DhtResult, DhtError> {
let mut timeout = 2000;
let mut raw: [Option<u32>; 2] = [None; 2];
self.tx_fifo.write(1);
while timeout > 0 && self.rx_fifo.is_empty() {
while timeout > 0 && raw[1].is_none() {
match self.rx_fifo.read() {
Some(d) => {
if raw[0].is_none() {
raw[0] = Some(d);
} else {
raw[1] = Some(d);
}
}
None => (),
}
delay.delay_ms(1);
timeout -= 1;
}
@ -71,20 +84,32 @@ impl<P: PIOExt, STI: StateMachineIndex> PicoDht<P, STI> {
return Err(DhtError::Timeout);
}
let raw = match self.rx_fifo.read() {
Some(d) => d,
None => {
self.sm.restart();
return Err(DhtError::ReadError);
}
};
let data = raw[0].unwrap();
let crc = raw[1].unwrap();
let t_raw = raw & 0x0000FFFF;
let h_raw = (raw & 0xFFFF0000) >> 16;
if Self::compute_crc(data) != crc {
return Err(DhtError::CrcMismatch(
raw[0].unwrap_or(0),
raw[1].unwrap_or(0),
));
}
let t_raw = data & 0x0000FFFF;
let h_raw = (data & 0xFFFF0000) >> 16;
Ok(DhtResult {
temperature: t_raw as f32 / 10.0,
humidity: h_raw as f32 / 10.0,
})
}
fn compute_crc(data: u32) -> u32 {
let mut crc: u32 = 0;
crc += data & 0x000000FF;
crc += (data & 0x0000FF00) >> 8;
crc += (data & 0x00FF0000) >> 16;
crc += (data & 0xFF000000) >> 24;
crc % 256
}
}