Is there a way to get the occupied buffer size in case we want to block, if the uart is to slow?

[initdb]

We have the problem that the TriceBuffer fills up to fast and the uart isn't fast enough to write out all messages and free up the buffer.
I would like an option to check if the buffer is to full and for example block the code and give the uart time to write out some messages.

[rokath]

• You have to enable diagnostics #define TRICE_DIAGNOSTICS 1 inside your triceConfig.h file.
• Inside triceCheck.c you can find the function void TriceLogDiagnosticValues( void ). Copy it into your project and rename/adapt it to your needs.
• You can reduce the data amount:
  • Use timestamps only when really needed: Take trice instead of TRice.
  • Use trice8 or trice16 instead of trice (defaults to trice32) to save parameter space. Anyway the default TCOBS compression reduces the data also.
  • You can add #define TRICE_TRANSFER_MODE TRICE_PACK_MULTI_MODE to your triceConfig.h file when using #define TRICE_BUFFER TRICE_DOUBLE_BUFFER. This packs several trice messages together for TCOBS before adding the 0-delimiter byte after a frame. If for example in your double buffer 20 trice messages when TriceTransfer() is called, at least 19 bytes less are transferred.
  • Call TriceTransfer() more often to avoid unnecessary breaks in the transmit data stream.
• You can inrease the baud rate. Beyond 115200 baud, you should use DMA transfer to the UART.
• If you need the logging only during development consider RTT, especially #define TRICE_SEGGER_RTT_32BIT_DIRECT_WRITE 1 which finishes in about 100 MCU clocks.
• You can also selectively transmit according the ID numbers to different channels. The target code exists for that but the automatic ID management is not done yet. But you can edit the IDs also manually.

[initdb]

thank you for the answer.

• the proplem arises from an external lib where we override the printf style logging function, this means we have to use a lot of TRICE_S. which increases the amount of transmitted data by a lot. The dynamic strings are already truncated.
• i will try the #define TRICE_TRANSFER_MODE TRICE_PACK_MULTI_MODE, i also got better results with the TRICE_RING_BUFFER.
• the TriceTransfer() function is called every 10ms
• increasing the baud rate to 230400 resulted in inconsistend buffer errors with the windows trice client.
• i will try the #define TRICE_SEGGER_RTT_32BIT_DIRECT_WRITE 1
• at the moment i added a ring buffer check on the printf override of the external lib. This blocks the application if the buffer is close to an overflow, but results in a stable output with no hard fault, overflows or buffer inconsistencies:

extern uint32_t* TriceBufferWritePosition;
extern uint32_t* TriceRingBufferReadPosition;

// function to check the state of the ringbuffer
int isRingBufferAlmostFull() {
    uint32_t bufferSize = TRICE_DEFERRED_BUFFER_SIZE >> 2;

    // calculate distance
    int distance = TriceBufferWritePosition - TriceRingBufferReadPosition;

    // check if write pointer is close to overflowing readpointer
    if (distance >= (bufferSize - 1 - SAFETY_THRESHOLD_BYTES)) {
        return 1; // the write pointer is close to overflowing the read pointer
    }  else {
        return 0; // ok
    }
}

...
void printfOverride(const char *pFormat, ...) {
...
while (isRingBufferAlmostFull()) {
        sleep(10);
}
...
TRICE_S(...)
}

[rokath]

Isn't it posible to patch the external library code according TriceUserGuide.md#255-user-code-adaption? The TriceTransfer() call every 1ms should be possible. As said, above 115200 baud DMA is recommended. But if RTT is possble for you, that would be the best way to go.