Struct Search 

pub struct Search { /* private fields */ }

Enumerates the devices on a bus, one ROM code per call.

This is the binary tree walk the 1-Wire specification defines: after a SEARCH_ROM every device sends each bit of its ROM code and then the complement, the controller writes back the branch it takes, and the devices whose bit differs drop out until one remains. Each call to next returns the next device; the walk remembers where it branched and returns None once every device has been named.

Examples

use pamoja_hal::onewire::{OneWireBus, RomCode, Search};

fn thermometers<B: OneWireBus>(bus: &mut B) -> Result<Vec<RomCode>, B::Error> {
    let mut found = Vec::new();
    let mut search = Search::new();
    while let Some(rom) = search.next(bus).map_err(|error| match error {
        pamoja_hal::onewire::OneWireError::Pin(error) => error,
        _ => unreachable!("a bus with no devices or a bad CRC ends the search"),
    })? {
        if rom.family() == 0x28 {
            found.push(rom);
        }
    }
    Ok(found)
}

Implementations

impl Search

pub fn new() -> Search

Starts a search that visits every device.

Returns

The search, positioned before the first device.

pub fn alarms() -> Search

Starts a search that visits only the devices with an alarm condition.

Returns

The search, positioned before the first alarming device.

pub fn next<B: OneWireBus>( &mut self, bus: &mut B, ) -> Result<Option<RomCode>, OneWireError<B::Error>>

Finds the next device on bus.

Arguments

• bus - the bus to search.

Returns

The next device’s ROM code, or None when every device has been returned or no device answered the reset.

Errors

Returns OneWireError::Crc if a ROM code arrived corrupted, which happens when a device joins or drops mid-search, or the controller’s error.

Trait Implementations

impl Clone for Search

fn clone(&self) -> Search

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Search

impl Debug for Search

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Search

fn default() -> Self

Returns the “default value” for a type.