This document describes a camera switch to drive cameras that require an active low shutter signal.
This camera switch is a variation of the Servo Camera Switch. Because of this the documentation here describes the variations between the two switch designs and the reader is expected to read this document in conjunction with the Servo Camera Switch documentation.
This page include links to the complete circuit diagram, the .HEX file required to program the 12F675, and a construction summary.
The switch consists of a PIC and a small number of standard components. The Servo Camera Switch connects inline between the receiver and the camera.
After completion of the Servo Camera Switch I realised that the same software would drive a camera directly with very little modification.
This provides a single set of switch features with either a servo output, or direct camera drive.
This switch offers all the features of the Servo Camera Switch, with a direct camera drive instead of a servo drive.
Note: the focus before shutter capability of the Servo Camera Switch is not available in this switch.
The output drive is an Active Low, normally Tri-State Signal. This means that when not taking a picture the PIC output is tri-state (ie. open-circuit). When the switch wishes to take a picture the PIC output is made active at 0 volts. This permits direct connection to the shutter control of the Aiptek Pencam 1.3, Dolphin Jazz, and many other cameras.
Programming functions similarly to the Servo Camera Switch programming mode. However, the following differences apply:
- Parameters 1, 2 and 3 are not used. Programming them will not alter the operation of the PIC shutter output.
- The PIC will activate the shutter signal for the sum of the focus time and the shutter time. It is recommended that the focus time be left at zero (0).
The files available for download are:
File Name Description cswitch.gif Rev A: Circuit diagram for Aiptek/Jazz Servo Switch csw.asm Rev 1.6: Source code for the switch csw.hex, csw.lst Rev 1.6: Assembled code and listing for the switch.
It is recommended that you follow the construction for the servo switch. However the output lead should be connected to the camera rather than a servo.
Because of the many possible camera modifications and voltage regulators that may be required some of the connection details are left ot the user.
For the Dolphin Jazz camera this switch can be connected directly to the camera battery terminals and shutter as shown here.