WIP.

logging:

15/04/2026

  • I decided to use the code from Azfar Rosdi.
  • I learnt that pulseIn(pin, state) is used to calculate how long certain pin go from !state to state. It returns the time spent in microseconds.
  • Now why did the water level indicator not work on my waffer jar?
  • I read from HandsOn Tech User Guide that the surface must have a minimum area of 0.5m2. Maybe that’s why, need to confirm it anyway.

04/01/2026

  • I learnt about SPIFFS (SPI Flash Filesystem). It’s a file system used for SPI NOR flash device; a memory commonly used for embedded devices GigaDevice.
  • I learnt that SPIFFS is mounted at /spiffs.
  • I learnt that SPIFFS store files in a flat structure. So, for example, if I store a file like /spiffs/dir/file1.txt, this file has a name “/dir/file1.txt” instead a file1.txt in a /dir/ directory SPIFFS.