Like every scuba diver (I have CMAS P1 qualifications) I wanted to have my own diving computer. Unfortunately I couldn’t afford one. So I decided to make one. I wanted to use LCD from Nokia 3310 mobile phone (LCD controller Philips PCD 8544, only 300 uA), AVR microcontroller, Honeywell pressure sensor 26PCDFA2G. Assembler source code can be found here.