Class espos_n2k::TwaiReceiver¶

ClassList > espos_n2k > TwaiReceiver

Reads CAN frames from the TWAI peripheral and emits them as CanMessage values, on the shared node's RX task.

#include <espos_n2k/twai_receiver.h>

Public Types¶

Type	Name
typedef std::function< void(const CanMessage &)>	FrameFn

Public Functions¶

Type	Name
	TwaiReceiver (const TwaiReceiverConfig & config={})
uint32_t	bus_off_count () const Bus-off events counted by the shared node since it came up.
bool	bus_running () const Is the shared TWAI node up? False means the driver never started (bad pins, a failed twai_new_node_onchip) which from a candump socket looks exactly like a bus with nothing on it.
uint32_t	error_count () const Bus errors seen by the controller, and the flags of the most recent one (arb_lost, bit_err, form_err, stuff_err, ack_err IDF's twai_error_flags_t).
bool	ever_received () const True if we have received at least one frame since boot.
uint32_t	frames_dropped () const
uint32_t	frames_received () const Frames the ISR accepted, and frames it had to drop because the queue was full.
uint32_t	last_error_flags () const
int64_t	seconds_since_last_rx () const Seconds since the last received frame.
void	set_on_frame (FrameFn fn) Called on the receiver task for every frame. Set before start() .
void	start ()
void	stop ()
	~TwaiReceiver ()

Public Types Documentation¶

typedef FrameFn¶

using espos_n2k::TwaiReceiver::FrameFn =  std::function<void(const CanMessage&)>;

Public Functions Documentation¶

function TwaiReceiver¶

explicit espos_n2k::TwaiReceiver::TwaiReceiver (
    const TwaiReceiverConfig & config={}
)

function bus_off_count¶

Bus-off events counted by the shared node since it came up.

uint32_t espos_n2k::TwaiReceiver::bus_off_count () const

function bus_running¶

Is the shared TWAI node up? False means the driver never started (bad pins, a failed twai_new_node_onchip) which from a candump socket looks exactly like a bus with nothing on it.

bool espos_n2k::TwaiReceiver::bus_running () const

function error_count¶

Bus errors seen by the controller, and the flags of the most recent one (arb_lost, bit_err, form_err, stuff_err, ack_err IDF's twai_error_flags_t).

uint32_t espos_n2k::TwaiReceiver::error_count () const

Errors rising while frames stay at zero is the signature of a bus that is wired but wrong: an ack error on every transmission means nothing else is listening, and a stuff or form error storm usually means the bitrate does not match.

function ever_received¶

True if we have received at least one frame since boot.

inline bool espos_n2k::TwaiReceiver::ever_received () const

function frames_dropped¶

uint32_t espos_n2k::TwaiReceiver::frames_dropped () const

function frames_received¶

Frames the ISR accepted, and frames it had to drop because the queue was full.

uint32_t espos_n2k::TwaiReceiver::frames_received () const

A rising drop count is a consumer that cannot keep up, not a bus problem.

function last_error_flags¶

uint32_t espos_n2k::TwaiReceiver::last_error_flags () const

function seconds_since_last_rx¶

Seconds since the last received frame.

inline int64_t espos_n2k::TwaiReceiver::seconds_since_last_rx () const

Returns INT64_MAX if no frame has ever been received. esp_timer_get_time() returns int64 microseconds since boot — overflows in ~292,000 years, so no rollover concerns. (Was rx_count_ uint32 which overflowed at ~20 days of busy N2K traffic.)

function set_on_frame¶

Called on the receiver task for every frame. Set before start() .

inline void espos_n2k::TwaiReceiver::set_on_frame (
    FrameFn fn
)

function start¶

void espos_n2k::TwaiReceiver::start ()

function stop¶

void espos_n2k::TwaiReceiver::stop ()

function ~TwaiReceiver¶

espos_n2k::TwaiReceiver::~TwaiReceiver ()

The documentation for this class was generated from the following file espos_n2k/include/espos_n2k/twai_receiver.h