Daniel Schramm
Projects
Schliessanlage
Cat5 Cable Checker
Einschaltverzögerung
Belichtungstimer
Exposure Timer 2
Solder Station
Slave Flash
MP3 Player
MP3 Player Touch
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