countdown timer | Miscellaneous › Others › countdown timer This topic has 0 replies, 1 voice, and was last updated 8 years, 7 months ago by Adrian Surtees. Viewing 1 post (of 1 total) Author Posts February 4, 2016 at 11:10 pm #4266 Adrian SurteesParticipant Countdown timer using 8051 microcontroller (AT89C51) – I need an hour countdown and this circuit is great but is it possible to automatically reset to one hour rather than zero? Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In