Struct EspNow

pub struct EspNow<'d> { /* private fields */ }

Available on crate feature unstable only.

ESP-NOW is a kind of connection-less Wi-Fi communication protocol that is defined by Espressif. In ESP-NOW, application data is encapsulated in a vendor-specific action frame and then transmitted from one Wi-Fi device to another without connection. CTR with CBC-MAC Protocol(CCMP) is used to protect the action frame for security. ESP-NOW is widely used in smart light, remote controlling, sensor, etc.

For convenience, by default there will be a broadcast peer added on the STA interface.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

Implementations

impl<'d> EspNow<'d>

pub fn split(self) -> (EspNowManager<'d>, EspNowSender<'d>, EspNowReceiver<'d>)

Splits the EspNow instance into its manager, sender, and receiver components.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn set_channel(&self, channel: u8) -> Result<(), EspNowError>

Set primary Wi-Fi channel. Should only be used when using ESP-NOW without AP or STA.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn version(&self) -> Result<u32, EspNowError>

Get the version of ESP-NOW.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn add_peer(&self, peer: PeerInfo) -> Result<(), EspNowError>

Add a peer to the list of known peers.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn remove_peer(&self, peer_address: &[u8; 6]) -> Result<(), EspNowError>

Remove the given peer.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn modify_peer(&self, peer: PeerInfo) -> Result<(), EspNowError>

Modify a peer information.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn peer(&self, peer_address: &[u8; 6]) -> Result<PeerInfo, EspNowError>

Get peer by MAC address.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn fetch_peer(&self, from_head: bool) -> Result<PeerInfo, EspNowError>

Fetch a peer from peer list.

Only returns peers which address is unicast, for multicast/broadcast addresses, the function will skip the entry and find the next in the peer list.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn peer_exists(&self, peer_address: &[u8; 6]) -> bool

Check is peer is known.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn peer_count(&self) -> Result<PeerCount, EspNowError>

Get the number of peers.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn set_pmk(&self, pmk: &[u8; 16]) -> Result<(), EspNowError>

Set the primary master key.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn set_wake_window(&self, wake_window: u16) -> Result<(), EspNowError>

Set wake window for esp_now to wake up in interval unit.

Window is milliseconds the chip keep waked each interval, from 0 to 65535.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn set_rate(&self, rate: WifiPhyRate) -> Result<(), EspNowError>

Configure ESP-NOW rate.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn send<'s>( &'s mut self, dst_addr: &[u8; 6], data: &[u8], ) -> Result<SendWaiter<'s>, EspNowError>

Send data to peer.

The peer needs to be added to the peer list first.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn receive(&self) -> Option<ReceivedData>

Receive data.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

impl EspNow<'_>

pub fn receive_async(&mut self) -> ReceiveFuture<'_>

This function takes mutable reference to self because the implementation of ReceiveFuture is not logically thread safe.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.

pub fn send_async<'s, 'r>( &'s mut self, dst_addr: &'r [u8; 6], data: &'r [u8], ) -> SendFuture<'s, 'r>

The returned future must not be dropped before it’s ready to avoid getting wrong status for sendings.

Stability

This API is marked as unstable and is only available when the unstable crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.