Building a timer with countdown and buttons to set the timer is probably among the most "tried and tested" PICAXE uses, but at least the applications vary. In this case I wanted build an UV exposure box for photographic PCB development, and being a little forgetful at times, I thought it would be wise to add a timer to the box to automatically turn it off.
Of course, the good old 555 and a regular potentiometer would suffice, but why not set the time with a few buttons and have it count down? All it takes is a PICAXE 08M, a relay, and a few components for the display and the buttons.
Code, schematic, PCB, and a picture of the box to be found here.
Of course, the good old 555 and a regular potentiometer would suffice, but why not set the time with a few buttons and have it count down? All it takes is a PICAXE 08M, a relay, and a few components for the display and the buttons.
Code, schematic, PCB, and a picture of the box to be found here.