Remote Control of Blinds
In southern Germany, external blinds made up of heavy plastic profiles are extremely common. For home theater, these are excellent: they provide an almost perfect darkness, even with sunlight outside. Electric motors are available, like the Rollotron 9200. Even remote control, and light sensible controls, are available. The drawback with such solutions is of course (not counting the price!) that it is unclear if and how such devices can be integrated in the whole system. For obvious reasons, I wanted to use the Intertechno CMR-500. This thing switches two "channels" with one connector in common. The objective was to remotely control the "up" and the "down" button. Unfortunately, a look at the signals with an oscilloscope showed that there were no "common" for both "up" and "down". Therefore, I equipped the Rollotron with two reed relays, feed by 5 Volts. The modification is described in pictures.
On two windows, more space was available, so instead of the somewhat expensive Rollotron, a cheaper and bulkier device could be used. Also it has the advantage that it can be controlled by the CMR-500 directly, with no relays.
All five blinds in my apartment are remotely controllable.