hugo
October 20, 2020, 5:24pm
1
Hi
Somehow I had this working on an Arduino Mega at some time but I “tried to fix what was not broken” and now it is not working anymore and I don’t know what is wrong. I know canardTxPush() is returning -2 but i don’t know why. Anybody can help with some insight please?
The code is here:
The relevant case is this one:
/// The library itself, however, does not use or check this value in any way, so it can be zero if not needed.
///
/// The function returns the number of frames enqueued into the prioritized TX queue (which is always a positive
/// number) in case of success (so that the application can track the number of items in the TX queue if necessary).
/// In case of failure, the function returns a negated error code: either invalid argument or out-of-memory.
///
/// An invalid argument error may be returned in the following cases:
/// - Any of the input arguments are NULL.
/// - The remote node-ID is not CANARD_NODE_ID_UNSET and the transfer is a message transfer.
/// - The remote node-ID is above CANARD_NODE_ID_MAX and the transfer is a service transfer.
/// - The priority, subject-ID, or service-ID exceed their respective maximums.
/// - The transfer kind is invalid.
/// - The payload pointer is NULL while the payload size is nonzero.
/// - The local node is anonymous and a message transfer is requested that requires a multi-frame transfer.
/// - The local node is anonymous and a service transfer is requested.
/// The following cases are handled without raising an invalid argument error:
/// - If the transfer-ID is above the maximum, the excessive bits are silently masked away
/// (i.e., the modulo is computed automatically, so the caller doesn't have to bother).
///
/// An out-of-memory error is returned if a TX frame could not be allocated due to the memory being exhausted.
/// In that case, all previously allocated frames will be deallocated automatically. In other words, either all frames
The maximum subject-ID value is 8191 (changed in UAVCAN Spec v1.0-beta, used to be 32767):
/// The error code 1 is not used because -1 is often used as a generic error code in 3rd-party code.
#define CANARD_ERROR_INVALID_ARGUMENT 2
#define CANARD_ERROR_OUT_OF_MEMORY 3
/// MTU values for the supported protocols.
/// Per the recommendations given in the UAVCAN/CAN Specification, other MTU values should not be used.
#define CANARD_MTU_CAN_CLASSIC 8U
#define CANARD_MTU_CAN_FD 64U
/// Parameter ranges are inclusive; the lower bound is zero for all. See UAVCAN/CAN Specification for background.
#define CANARD_SUBJECT_ID_MAX 8191U
#define CANARD_SERVICE_ID_MAX 511U
#define CANARD_NODE_ID_MAX 127U
#define CANARD_PRIORITY_MAX 7U
#define CANARD_TRANSFER_ID_BIT_LENGTH 5U
#define CANARD_TRANSFER_ID_MAX ((1U << CANARD_TRANSFER_ID_BIT_LENGTH) - 1U)
/// This value represents an undefined node-ID: broadcast destination or anonymous source.
/// Library functions treat all values above CANARD_NODE_ID_MAX as anonymous.
#define CANARD_NODE_ID_UNSET 255U
This change is described in the changelog here:
You need to update your subject-ID constants.