Log service

Level-filtered logging service. Provides SPP_LOG* macros that route output through a swappable callback function. No default output is set — call SPP_SERVICES_LOG_setOutput() to wire up a handler, or use SPP_CORE_boot() which automatically bridges log output to the pub/sub bus.

---

Files

File	Description
log.h	Public API, log macros, SPP_LogLevel_t
log.c	Implementation

---

Log levels

K_SPP_LOG_NONE    = 0   // Silence all output
K_SPP_LOG_ERROR   = 1   // Critical errors only
K_SPP_LOG_WARN    = 2   // Warnings and errors
K_SPP_LOG_INFO    = 3   // Normal operational messages
K_SPP_LOG_DEBUG   = 4   // Detailed debug output
K_SPP_LOG_VERBOSE = 5   // Full trace (default after init)

Messages with a level higher than the current filter are suppressed.

---

API

SPP_RetVal_t    SPP_SERVICES_LOG_init(void);
void            SPP_SERVICES_LOG_setLevel(SPP_LogLevel_t level);
SPP_LogLevel_t  SPP_SERVICES_LOG_getLevel(void);
void            SPP_SERVICES_LOG_setOutput(SPP_LogOutputFn_t fn);

---

Macros

SPP_LOGE("TAG", "SPI error %d", ret);    // error
SPP_LOGW("TAG", "pool at %d%%", pct);    // warning
SPP_LOGI("TAG", "service started");      // info
SPP_LOGD("TAG", "seq=%u ts=%u", s, t);  // debug
SPP_LOGV("TAG", "raw bytes: %02X", b);  // verbose

The tag is a short string identifying the module — use a module-level const char *:

static const char *const k_tag = "BMP390";
SPP_LOGI(k_tag, "altitude = %.2f m", altitude);

---

Log → pub/sub bridge

SPP_CORE_boot() automatically installs a log output function that formats each SPP_LOG* call as a K_SPP_APID_LOG packet and publishes it on the bus. This lets the SD card logger capture log messages alongside sensor data without any extra setup.

A reentrancy guard (s_logBusy) prevents infinite recursion: if a subscriber itself calls SPP_LOGE(), the nested call is silently dropped.

---

Custom output callback

// Redirect to UART on embedded target
static void uartLogOutput(const char *p_tag, SPP_LogLevel_t level,
                           const char *p_msg)
{
    uart_write_bytes(UART_NUM_0, p_msg, strlen(p_msg));
    uart_write_bytes(UART_NUM_0, "\n", 1);
}

SPP_SERVICES_LOG_setOutput(uartLogOutput);

Pass NULL to disable log output.