Friedland DC55 Window Sensor Reverse Engineering pt 2


is not good enough for me.

I can’t accept a single packet for 4 different states, that’s just crazy. It’s great if you’ve got an unarmed alarm system, then you close the windows, then you arm the system. It’s not when you’re interested in open/closed tampered/okay, to alert you in different ways. Tamper? Probably fell off if impermanently mounted in a rental. Open? Well, that window is open. For my house, I often forget to close a few specific windows at night, and it sometimes causes my heating to come on. Instead of waste the gas and electricity, I’d rather see a dashboard of my window states.

In the last episode, I opened the case and identified the microcontroller: PIC16F627A. Now it’s time to see if I can reprogram this microcontroller with probes, and what software I need to use to put software onto it. I would also need to completely map the pinout connections, so I know what all the pins are connected to. I don’t care much about the resistor values and so forth - the circuit works in place.

I also need to be able to reprogram the PIC16F627A. This is going to be the first roadblock - I have most of the tools required for SMD soldering, but need to get some solder paste.

I picked up a PICKIT3 clone from Amazon since their shipping was fast. I then started work printing a nano SMD probe. This is going to take a few days while I wait for the printer and acupuncture needles to ship. I picked up some LED strip wiring recently, so I’ve got some wiring for the probe arms already.