Making my Blinds smart and open automatically

The blinds in my bedroom in my flat should open automatically and gradually to wake me up. Opening time should be setable via webinterface and may depend on calculcated sunrise times as well as on weather. Since it's a rented flat, all changes must be easily reversible or easily be handed over and maintainable by a non-technical person.

• Rollladenmotor
  This was the first option I looked at. Could be easily controlled with a µC and some relays. Decided against it because:
  • reversing it is at least as much work as installing it
  • handing it over to another tenant would mean adding easily controlled and maintainable commercial buttons and controller hardware, which I wanted to avoid
• Superrollo GW60
  • decided on this, since it seemed like a easily installed plug in solution
  • the option to add a ZB40 433MHz remote suggested the GW60 should be very hackable.

In my endeavour to be least invasive as possible, I first tried to construct a protoboard with spring contacts that would slide into the GW60 just like the ZB40 does. Inside the GW60 there are 8 contacts for a slide-in addon. The ZB40, as seen from the product image, connects to the first four. The result came out rather well that I expected but then turned out to have contact problems with the pins. Then I decided to just solder on some wires.

Measuring the pins on the GW60 I discovered the following:

The GW60 is supplied with 24V by a separate DC power supply.

Next step: figuring out how to control the GW60 via Pins 2 and 3.

After several attempts to just toggle pins resulted in nothing, we suspected some serial interface. Opening up the GW60 again, I traced the lines to two 1KOhm resistors and then to the TX/RX input pins of a PIC16F90 microcontroller.

That strongly suggested a TTL serial interface, so I broke out my USB-TTL-serial connector.

for speed in 38400 19200 9600 4800 ; do stty -F /dev/ttyUSB0 $speed -raw; for ((i=0;i<0x10000; i++)); do echo -e "$(printf "\\\x%x" $i)" >| /dev/ttyUSB0; done; done