Reading the DS18B20 temperature sensor with this Rust function - rust

sorry, i'm a complete newbie to Rust. I try to read the temp from the sensor mentioned above on a Raspberry Pi using the code provided on this site: https://github.com/fuchsnj/ds18b20
Actually, i want to call the function
get_temperature
but i have no idea how to declare the parameters, especially delay and one_wire_bus.
I was able to resolve all the 'namespaces' or name bindings (sorry, coming from C++) but got stuck with the parameters. Can someone give me an example how to call and use this function like this:
use ds18b20::{Resolution, Ds18b20};
use embedded_hal::blocking::delay::{DelayUs, DelayMs};
use embedded_hal::digital::v2::{OutputPin, InputPin};
use one_wire_bus::{self, OneWire, OneWireResult};
use core::fmt::Debug;
use std::io::Write;
fn main() {
let mut delay = ?????;
let mut one_wire_bus = ?????;
let mut tx = ?????; //&mut Vec::new();
let temp = get_temperature(delay, tx, one_wire_bus);
...
//do something whit the temp
...
}
This is the implementation of the function from the website
fn get_temperature<P, E>(
delay: &mut (impl DelayUs<u16> + DelayMs<u16>),
tx: &mut impl Write,
one_wire_bus: &mut OneWire<P>,
) -> OneWireResult<(), E>
where
P: OutputPin<Error=E> + InputPin<Error=E>,
E: Debug
{
// initiate a temperature measurement for all connected devices
ds18b20::start_simultaneous_temp_measurement(one_wire_bus, delay)?;
// wait until the measurement is done. This depends on the resolution you specified
// If you don't know the resolution, you can obtain it from reading the sensor data,
// or just wait the longest time, which is the 12-bit resolution (750ms)
Resolution::Bits12.delay_for_measurement_time(delay);
// iterate over all the devices, and report their temperature
let mut search_state = None;
loop {
if let Some((device_address, state)) = one_wire_bus.device_search(search_state.as_ref(), false, delay)? {
search_state = Some(state);
if device_address.family_code() != ds18b20::FAMILY_CODE {
// skip other devices
continue;
}
// You will generally create the sensor once, and save it for later
let sensor = Ds18b20::new(device_address)?;
// contains the read temperature, as well as config info such as the resolution used
let sensor_data = sensor.read_data(one_wire_bus, delay)?;
writeln!(tx, "Device at {:?} is {}°C", device_address, sensor_data.temperature);
} else {
break;
}
}
Ok(())
}

Related

VST3 Sampler using NIH-Plug

I'm trying to make a NIH-Plug sample player. This wouldn't be a pitch shifting plugin, but per note a different sample. (note A1 -> A1.wav). Are there any resources, about this subject. I'm also trying to cache the samples, but it's not really succeeding.
Ultimately, I'm going to use include_dir instead of include_bytes.
Here's a PolyModSynth demo, which I'm using and trying to adapt to playing samples.
Thank you.
let C1 = include_bytes!("samples/c1.wav");
let CS1 = include_bytes!("samples/c#1.wav");
fn process(
&mut self,
buffer: &mut Buffer,
_aux: &mut AuxiliaryBuffers,
context: &mut impl ProcessContext<Self>
) -> ProcessStatus {
let mut next_event = context.next_event();
for (sample_id, wav_sample) in buffer.iter_samples().zip(wav_vec) {
// Act on the next MIDI event
while let Some(event) = next_event {
if event.timing() > (sample_id as u32) {
break;
}
// handle the MIDI event as needed
// ...
next_event = context.next_event();
}
// Set the sample value in the output buffer
for sample in channel_samples {
*sample = self.sample_value[sample_id];
}
}

How to create threads in a for loop and get the return value from each?

I am writing a program that pings a set of targets 100 times, and stores each RTT value returned from the ping into a vector, thus giving me a set of RTT values for each target. Say I have n targets, I would like all of the pinging to be done concurrently. The rust code looks like this:
let mut sample_rtts_map = HashMap::new();
for addr in targets.to_vec() {
let mut sampleRTTvalues: Vec<f32> = vec![];
//sample_rtts_map.insert(addr, sampleRTTvalues);
thread::spawn(move || {
while sampleRTTvalues.len() < 100 {
let sampleRTT = ping(addr);
sampleRTTvalues.push(sampleRTT);
// thread::sleep(Duration::from_millis(5000));
}
});
}
The hashmap is used to tell which vector of values belongs to which target. The problem is, how do I retrieve the updated sampleRTTvalues from each thread after the thread is done executing? I would like something like:
let (name, sampleRTTvalues) = thread::spawn(...)
The name, being the name of the thread, and sampleRTTvalues being the vector. However, since I'm creating threads in a for loop, each thread is being instantiated the same way, so how I differentiate them?
Is there some better way to do this? I've looked into schedulers, future, etc., but it seems my case can just be done with simple threads.
I go the desired behavior with the following code:
use std::thread;
use std::sync::mpsc;
use std::collections::HashMap;
use rand::Rng;
use std::net::{Ipv4Addr,Ipv6Addr,IpAddr};
const RTT_ONE: IpAddr = IpAddr::V4(Ipv4Addr::new(127,0,0,1));
const RTT_TWO: IpAddr = IpAddr::V6(Ipv6Addr::new(0,0,0,0,0,0,0,1));
const RTT_THREE: IpAddr = IpAddr::V4(Ipv4Addr::new(127,0,1,1));//idk how ip adresses work, forgive if this in invalid but you get the idea
fn ping(address: IpAddr) -> f32 {
rand::thread_rng().gen_range(5.0..107.0)
}
fn main() {
let targets = [RTT_ONE,RTT_TWO,RTT_THREE];
let mut sample_rtts_map: HashMap<IpAddr,Vec<f32>> = HashMap::new();
for addr in targets.into_iter() {
let (sample_values,moved_values) = mpsc::channel();
let mut sampleRTTvalues: Vec<f32> = vec![];
thread::spawn(move || {
while sampleRTTvalues.len() < 100 {
let sampleRTT = ping(addr);
sampleRTTvalues.push(sampleRTT);
//thread::sleep(Duration::from_millis(5000));
}
});
sample_rtts_map.insert(addr,moved_values.recv().unwrap());
}
}
note that the use rand::Rng can be removed when implementing, as it is only so the example works. what this does is pass data from the spawned thread to the main thread, and in the method used it waits until the data is ready before adding it to the hash map. If this is problematic (takes a long time, etc.) then you can use try_recv instead of recv which will add an error / option type that will return a recoverable error if the value is ready when unwrapped, or return the value if it's ready
You can use a std::sync::mpsc channel to collect your data:
use std::collections::HashMap;
use std::sync::mpsc::channel;
use std::thread;
fn ping(_: &str) -> f32 { 0.0 }
fn main() {
let targets = ["a", "b"]; // just for example
let mut sample_rtts_map = HashMap::new();
let (tx, rx) = channel();
for addr in targets {
let tx = tx.clone();
thread::spawn(move || {
for _ in 0..100 {
let sampleRTT = ping(addr);
tx.send((addr, sampleRTT));
}
});
}
drop(tx);
// exit loop when all thread's tx have dropped
while let Ok((addr, sampleRTT)) = rx.recv() {
sample_rtts_map.entry(addr).or_insert(vec![]).push(sampleRTT);
}
println!("sample_rtts_map: {:?}", sample_rtts_map);
}
This will run all pinging threads simultaneously, and collect data in main thread synchronously, so that we can avoid using locks. Do not forget to drop sender in main thread after cloning to all pinging threads, or the main thread will hang forever.

Peripheral Initialisation of GPIO Output with stm32f1xx_hal on bluepill development board

I would like to initialize a basic output GPIO pin on my blue pill board. I am using Rust and the stm32f1xx_hal crate. I want to create a struct Peripherals which holds the handle to the output in the following way:
use cortex_m_rt;
use stm32f1xx_hal::{
pac,
prelude::*,
gpio,
afio,
serial::{Serial, Config},
};
use crate::pac::{USART1};
type GpioOutput = gpio::gpioc::PC13<gpio::Output<gpio::PushPull>>;
pub struct Peripherals{
led: Option<GpioOutput>
}
impl Peripherals {
fn init() -> Peripherals {
let dp = pac::Peripherals::take().unwrap();
let cp = cortex_m::Peripherals::take().unwrap();
// set clock frequency to internal 8mhz oscillator
let mut rcc = dp.RCC.constrain();
let mut flash = dp.FLASH.constrain();
let clocks = rcc.cfgr.sysclk(8.mhz()).freeze(&mut flash.acr);
// access PGIOC registers
let mut gpioc = dp.GPIOC.split(&mut rcc.apb2);
return Peripherals{
led: Peripherals::init_led(&mut gpioc)
}
}
fn init_led(gpioc: &mut gpio::gpioc::Parts) -> Option<GpioOutput> {
let led = &gpioc.pc13.into_push_pull_output(&mut gpioc.crh);
return Some(led);
}
}
This code does not work, since init_led returns Option<&GpioOutput>. Now I am wondering if it makes sense to use a lifetime parameter in the Peripherals struct and store a reference to the GpioOutput within the struct. Or is it more sensible to store the unreferenced value - and how would I implement either of these options?
The only solution which seems to work is moving the init_led code to the scope of the init function:
return Peripherals{
led: Some(gpioc.pc13.into_push_pull_output(&mut gpioc.crh))
}
But i would like to seperate that code within its own function. How can i do that?
Ok, i figured out a way in case someone else is having the same problem:
pub fn init() -> Peripherals {
let dp = pac::Peripherals::take().unwrap();
let cp = cortex_m::Peripherals::take().unwrap();
// set clock frequency to internal 8mhz oscillator
let rcc = dp.RCC.constrain();
let mut flash = dp.FLASH.constrain();
// access PGIOC and PGIOB registers and prepare the alternate function I/O registers
let mut apb2 = rcc.apb2;
let gpioc = dp.GPIOC.split(&mut apb2);
let clocks = rcc.cfgr.sysclk(8.mhz()).freeze(&mut flash.acr);
return Peripherals{
led: Peripherals::init_led(gpioc)
}
}
fn init_led(mut gpioc: stm32f1xx_hal::gpio::gpioc::Parts) -> Option<GpioOutput> {
let led = gpioc.pc13.into_push_pull_output(&mut gpioc.crh);
return Some(led);
}
I am just wondering if this is the correct way to do it or will it create extra overhead, because i am passing gpioc by value instead of by reference in the init_led function?

How can i controll a 8x8 led-matrix display Max7219 with a raspberrypi in rust?

I want to manually control every single dot on 4 together chained 8*8 led-matrices controlled by the max7219 microcontroller via the SPI interface.
I already hooked up the clock, master-output/slave-input and ChipSelect signal to my osciloscope and everything seems to work the way it should be.
But I am only able to get the display kind of working by sending random data to it and I do not know how that data gets encoded.
Here is the code
use rand::Rng;
use std::io;
use std::io::prelude::*;
use spidev::{Spidev, SpidevOptions, SpidevTransfer, SpiModeFlags};
// Read the state of GPIO4 on a raspberry pi. /dev/gpiochip0
// maps to the driver for the SoC (builtin) GPIO controller.
fn main() -> Result<(), gpio_cdev::Error> {
let mut spi = create_spi().unwrap();
write_spi(&mut spi);
Ok(())
}
fn write_spi(spi: &mut Spidev) -> io::Result<()> {
let mut rng = rand::thread_rng();
loop {
let mut tx_buf = [0u8; 8];
for i in 0..8 {
tx_buf[i] = rng.gen_range(0..255);
}
spi.write(&tx_buf);
}
Ok(())
}
fn create_spi() -> io::Result<Spidev> {
let mut spi = Spidev::open("/dev/spidev0.0")?;
let options = SpidevOptions::new()
.bits_per_word(8)
.max_speed_hz(10_000)
.mode(SpiModeFlags::SPI_MODE_0)
.build();
spi.configure(&options)?;
Ok(spi)
}
What data must be sent to get it working?

Is it possible to compile a Vulkano shader at runtime?

I've been using Vulkano in order to get some simple 3D graphics going on. Generally, I like to write my GLSL shaders in text and restart my program, or even changing shaders while the program is running. The examples given in Vulkano appear to use a macro to convert the GLSL to some form of SPIR-V based shader with Rust functions attached, but the GLSL is actually compiled into the binary (even when using a path to a file).
I've managed to get the crate shaderc to build my SPIR-V on the fly:
let mut f = File::open("src/grafx/vert.glsl")
.expect("Can't find file src/bin/runtime-shader/vert.glsl
This example needs to be run from the root of the example crate.");
let mut source = String::new();
f.read_to_string(&mut source);
//let source = "#version 310 es\n void EP() {}";
let mut compiler = shaderc::Compiler::new().unwrap();
let mut options = shaderc::CompileOptions::new().unwrap();
options.add_macro_definition("EP", Some("main"));
let binary_result = compiler.compile_into_spirv(
&source, shaderc::ShaderKind::Vertex,
"shader.glsl", "main", Some(&options)).unwrap();
assert_eq!(Some(&0x07230203), binary_result.as_binary().first());
let text_result = compiler.compile_into_spirv_assembly(
&source, shaderc::ShaderKind::Vertex,
"shader.glsl", "main", Some(&options)).unwrap();
assert!(text_result.as_text().starts_with("; SPIR-V\n"));
//println!("Compiled Vertex Shader: {}", text_result.as_text());
let vert_spirv = {
unsafe { ShaderModule::new(device.clone(), binary_result.as_binary_u8()) }.unwrap()
};
vert_spirv
So far, so good, we have a ShaderModule which seems to be the first step. However, we we actually need is a GraphicsEntryPoint which we can then put into our GraphicsPipeline. Apparently, GraphicsPipeline is where we string together our shaders, triangles and depth maps and all that lovely stuff.
Trouble is, I've no idea what is going on with the code that performs this feat:
pub fn shade_vertex <'a, S> (vert_spirv: &'a Arc<ShaderModule>) ->
GraphicsEntryPoint<'a, S, VertInput, VertOutput, VertLayout> {
let tn = unsafe {
vert_spirv.graphics_entry_point(
CStr::from_bytes_with_nul_unchecked(b"main\0"),
VertInput,
VertOutput,
VertLayout(ShaderStages { vertex: true, ..ShaderStages::none() }),
GraphicsShaderType::Vertex
)
};
tn
}
Specifically, what is VertInput and VertOutput? I've copied them from the example.
This is the closest example I could find that deals with loading Shaders on the fly. It looks like Input and Output are looking for entry points into the SPIR-V or something but I've no idea what to do with that. I'm hoping there is a function somewhere in the existing macro that will just take care of this for me. I've gotten this far but I seem a little stuck.
Has anyone else tried loading shaders at runtime?
I'm using wgpu, I've made my device, render_pipeline multithreaded like this:
let rx = Arc::new(Mutex::new(rx));
let window = Arc::new(Mutex::new(window));
let fs = Arc::new(Mutex::new(fs));
let fs_module = Arc::new(Mutex::new(fs_module));
let render_pipeline = Arc::new(Mutex::new(render_pipeline));
let device = Arc::new(Mutex::new(device));
used notify to listen to change events:
notify = "4.0.15"
use notify::{RecommendedWatcher, Watcher, RecursiveMode};
//mainxx
let (tx, rx) = mpsc::channel();
let mut watcher: RecommendedWatcher =
Watcher::new(tx, Duration::from_millis(500)).unwrap();
log::info!("Starting watcher on {:?}", *FRAG_SHADER_PATH);
watcher.watch((*FRAG_SHADER_PATH).clone(), RecursiveMode::NonRecursive).unwrap();
Then spawn a thread that listens to changes:
thread::spawn(move || {
log::info!("Shader watcher thread spawned");
loop {
if let Ok(notify::DebouncedEvent::Write(..)) = rx.lock().unwrap().recv() {
log::info!("Write event in fragment shader");
window.lock().unwrap().set_title("Loading shader.frag...");
*fs.lock().unwrap() = load_fs().unwrap();
*fs_module.lock().unwrap() = load_fs_module(Arc::clone(&device), &Arc::clone(&fs).lock().unwrap());
*render_pipeline.lock().unwrap() = create_render_pipeline_multithreaded(Arc::clone(&device), Arc::clone(&fs_module));
render.lock().unwrap().deref_mut()();
window.lock().unwrap().set_title(TITLE);
};
}
});
where load_fs is a closure that uses glsl_to_spirv:
let load_fs = move || -> Result<Vec<u32>, std::io::Error> {
log::info!("Loading fragment shader");
let mut buffer = String::new();
let mut f = File::open(&*FRAG_SHADER_PATH)?;
f.read_to_string(&mut buffer)?;
// Load fragment shader
wgpu::read_spirv(
glsl_to_spirv::compile(
&buffer,
glsl_to_spirv::ShaderType::Fragment
).expect("Compilation failed")
)
};
There is an updated example for this in the vulkano repository.
I followed that and the example for shaderc-rs to get to this:
fn compile_to_spirv(src: &str, kind: shaderc::ShaderKind, entry_point_name: &str) -> Vec<u32> {
let mut f = File::open(src).unwrap_or_else(|_| panic!("Could not open file {}", src));
let mut glsl = String::new();
f.read_to_string(&mut glsl)
.unwrap_or_else(|_| panic!("Could not read file {} to string", src));
let compiler = shaderc::Compiler::new().unwrap();
let mut options = shaderc::CompileOptions::new().unwrap();
options.add_macro_definition("EP", Some(entry_point_name));
compiler
.compile_into_spirv(&glsl, kind, src, entry_point_name, Some(&options))
.expect("Could not compile glsl shader to spriv")
.as_binary()
.to_vec()
}
let vs = {
unsafe {
ShaderModule::from_words(
device.clone(),
&compile_to_spirv(
"shaders/triangle/vs.glsl",
shaderc::ShaderKind::Vertex,
"main",
),
)
}
.unwrap()
};
After this, vs can be used as in the example.

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