Daniel Schramm


     

Projects

Schliessanlage 

Cat5 Cable Checker 

Einschaltverzögerung 

Belichtungstimer 

Exposure Timer 2  Solder Station 

Slave Flash 

MP3 Player 

Home Automisation 

Can Bus Schield for Banana Pi 

PCBs

Veroeffentlichungen

Contact


  

Exposure timer 2

Overview

Some time ago i published a version of an exposure timer based on the AT90S2313 for a single sided exposure unit on this site.
Meanwhile a friend of mine helped me building a new double-sided exposure unit, which created the needs of a new timer. In this new version i also got rid of some design flaws in the previous version.
The Classic-AVR (AT90S2313) has high sesitivity in the reset circuit which makes it reset sometimes when the fluorescent tube are switched. The Software bypasses the problem as good as possible, but with the new Mega and Tiny series of the AVR microcontroller this can be enhanced.

Features

With this timer some new features are accompanied:
  • Memory for 3 exposure times for different PCBs
  • 3 start buttons to select up, down or both sides to be exposed
  • reduced to 3 segment Display (9 minutes 59 secods)
  • splitted into 2 PCBs, one for the Display, one for mains
  • the timer is now based on a clock crystal for less tolerance to real time
  • time is set with 2 buttons and saved to the eeprom when exposure is started
  • programming interface is now compatible to the STK200 programmer

Hardware

Pictures

Software


    last change to timer_mega8.html: 2004/09/03