acid-drop

- Hacking the planet from a LilyGo T-Deck using custom firmware
git clone git://git.acid.vegas/acid-drop.git
log.md (1644B)
      1 ```eval_rst
      2 .. include:: /header.rst
      3 :github_url: |github_link_base|/porting/log.md
      4 ```
      5 # Logging
      6 
      7 LVGL has a built-in *Log* module to inform the user about what is happening in the library.
      8 
      9 ## Log level
     10 To enable logging, set `LV_USE_LOG  1` in `lv_conf.h` and set `LV_LOG_LEVEL` to one of the following values:
     11 - `LV_LOG_LEVEL_TRACE` A lot of logs to give detailed information
     12 - `LV_LOG_LEVEL_INFO`  Log important events
     13 - `LV_LOG_LEVEL_WARN`  Log if something unwanted happened but didn't cause a problem
     14 - `LV_LOG_LEVEL_ERROR` Only critical issues, where the system may fail
     15 - `LV_LOG_LEVEL_USER` Only user messages
     16 - `LV_LOG_LEVEL_NONE`  Do not log anything
     17 
     18 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.
     19 
     20 ## Printing logs
     21 
     22 ### Logging with printf
     23 If your system supports `printf`, you just need to enable `LV_LOG_PRINTF` in `lv_conf.h` to send the logs with `printf`.
     24 
     25 
     26 ### Custom log function
     27 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()`.
     28 
     29 For example:
     30 
     31 ```c
     32 void my_log_cb(const char * buf)
     33 {
     34   serial_send(buf, strlen(buf));
     35 }
     36 
     37 ...
     38 
     39 
     40 lv_log_register_print_cb(my_log_cb);
     41 
     42 ```
     43 
     44 ## Add logs
     45 
     46 You can also use the log module via the `LV_LOG_TRACE/INFO/WARN/ERROR/USER(text)` or `LV_LOG(text)` functions. Here:
     47 
     48 -  `LV_LOG_TRACE/INFO/WARN/ERROR/USER(text)` append following information to your `text`
     49   - Log Level
     50   - \_\_FILE\_\_
     51   - \_\_LINE\_\_
     52   - \_\_func\_\_
     53 - `LV_LOG(text)` is similar to `LV_LOG_USER` but has no extra information attached.