Water level alarm

Water level alarm
The water outlet for the air conditioner was broken recently. The water get nowhere to go so we have to collect it in a tin bucket and empty it regularly to avoid overflow.  An egg timer was tried and it is kind of annoying since the time for the water to collect to a certain level was not ...

OLED message board

OLED message board
The low cost, small 3.3cm OLED display is fun to play with. The original one I bought has a built-in ROM for some retarded (Simplified) Chinese characters. The ROM is accessible via SPI and the display itself via I2C. Even though getting the characters from the ROM is doable, there is only a very limited ...