Logging and flash filesystem

Goals

• Learn the logging mechanisms provided by ESP-IDF
• Create your own partitions in SPI FLASH memory
• Mount a filesystem in FLASH memory

Documentation

To complete this assignment, you may need to check the slides discuss in the lectures and the official API documentation:

• Log
• SPI Flash and partitions
• FAT filesystem
• Wear levelling API

Logging to UART

Basic logging

Start from your basic (single-task) matrix multiply code (Lab 2). Insert ESP_LOG calls at least at 3 levels: ERROR, INFO and VERBOSE.

Modify logging level via menuconfig

Use menuconfig to select INFO as the minimum log level. Check that the VERBOSE messages are not shown

Multimodule

Create a new .c file in your project. Include there a couple of functions from your code. Remind to declare. a new TAG there. Include LOG macros in both files.

Modify logging level at runtime

Use esp_log_level_set()to set WARNING as the log level for the main file and VERBOSE for the other file. Check that the log output is correct.

Mounting FAT filesystem

In this step you will mount a FAT filesystem in a new partition created in the SPI FLASH existing in the board. Follow the example Wear Levelling ( [wear levelling example])https://github.com/espressif/esp-idf/tree/master/examples/storage/wear_levelling) ) and create a PlatformIO project to run it in your board:

• Create the PlatformIO project and copy the source code from the Wear Levelling example.
• Copy the file partitions_example.csv in the root folder of your project. Rename it as partitions.csv
• Modify the file platformio.ini to include:
  • monitor_port = /dev/ttyUSB1
  • upload_port = /dev/ttyUSB1
  • board_build.partitions = partitions.csv
• Run menuconfig (type pio run -t menuconfig in a PlatformIO terminal)
  • Partition Table --> PartitionTable --> Custom partition table CSV
  • Check that the name of the Custom parition CSV file in menuconfig is partitions.csv
  • Save the new configuration (press S) and quit (press Q)

Build, upload and execute. Monitor the output and check that the messages are the ones expected.

Redirecting the log to FLASH (optional)

This assignment is optional, but required if you want to obtain more than 6 / 10 in this assignment.

Starting from your chronometer code (or equivalent), include LOG messages (using ESP_LOG macros) and redirect the log to a file called log.txt that you will create in a FAT partition in SPI FLAG. Use esp_log_set_vprintf() to do the redirection. You should LOG:

• Every 5 seconds of the chronometer running, you must LOG a message.
• Every time the button is pressed
• Every time there is a long press (more than 4 seconds).

Note that you can still use printf() to write to the terminal.

Also, after 1 minute of functioning, you will read the first 5 lines of the log file and write them to the terminal (using printf()).