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1c2dc983b4
Co-authored-by: pengyiqiang <pengyiqiang@xiaomi.com>
1.5 KiB
1.5 KiB
Logging
LVGL has a built-in Log module to inform the user about what is happening in the library.
Log level
To enable logging, set LV_USE_LOG 1
in lv_conf.h
and set LV_LOG_LEVEL
to one of the following values:
LV_LOG_LEVEL_TRACE
A lot of logs to give detailed informationLV_LOG_LEVEL_INFO
Log important eventsLV_LOG_LEVEL_WARN
Log if something unwanted happened but didn't cause a problemLV_LOG_LEVEL_ERROR
Only critical issues, where the system may failLV_LOG_LEVEL_USER
Only user messagesLV_LOG_LEVEL_NONE
Do not log anything
The events which have a higher level than the set log level will be logged too. E.g. if you LV_LOG_LEVEL_WARN
, errors will be also logged.
Printing logs
Logging with printf
If your system supports printf
, you just need to enable LV_LOG_PRINTF
in lv_conf.h
to send the logs with printf
.
Custom log function
If you can't use printf
or want to use a custom function to log, you can register a "logger" callback with lv_log_register_print_cb()
.
For example:
void my_log_cb(lv_log_level_t level, const char * buf)
{
serial_send(buf, strlen(buf));
}
...
lv_log_register_print_cb(my_log_cb);
Add logs
You can also use the log module via the LV_LOG_TRACE/INFO/WARN/ERROR/USER(text)
or LV_LOG(text)
functions. Here:
LV_LOG_TRACE/INFO/WARN/ERROR/USER(text)
append following information to yourtext
- Log Level
- __FILE__
- __LINE__
- __func__
LV_LOG(text)
is similar toLV_LOG_USER
but has no extra information attached.