The design of the Enlarger Bluetooth Adapter is finally completed and a prototype is running in my darkroom.

The Enlarger Bluetooth Adapter allows the F-Stop Timer to control any photographic enlarger. The enlarger can be controlled through the power cord or using the foot switch signal from an existing power supply, such as featured on the Chromegatrol.

The adapter also has a extra outlet to plug your safe light in. This outlet is designed to be turned off when the enlarger lamp is turned on. This reduce the amount of light to which the paper is exposed during a long exposure.

This adapter is designed to be unobtrusive. Therefore, only a few darkroom safe LED are used to indicate power and connectivity of the adapter. 

The Enlarger Bluetooth Adapter is designed around an Arduino controller that communicate with the Android device using a bluetooth communication modem. Using an Arduino and releasing the controller source code gives the opportunity to anyone to easily hack the timer hardware to add any desired features. This also gives a possible DIY approach where someone could design its own power switching circuit to reuse salvaged parts.

If the demands is there, it would be possible for me to produce fully tested unit for a retail price of 160$. Please contact me if you are interested.