As a parent of 2 children and an obsession with cramming my hobbies in whenever I can, I decided to devise a means to remotely monitor my CNC (a ShapeOko) and also provide the ability for me to remotely shut it down if things go arwy during a milling session. I picked up a Foscam FI8918W IPCam at a ‘car boot’ sale (I love that name) when I was visting in England this past summer. For 5 quid nonetheless! I don’t think the folks selling it had any idea what it was worth. When asking the woman the standard “does it work” question, I knew I was going to get it regardless of my knowing that there was a good chance it would not work. Well, my luck prevailed, as the unit worked flawlessly with the exception that the smell of smoke was embedded in the plastic (would hate to see the previous owners lungs!). Yuk. Oh, and I also had to pickup a North American plug adapter – for all about$2 from DX.
My original plan was to pickup up an Arduino Network shield and use the camera to watch the CNC via custom webpage using streaming video and then, with some buttons, call the Arduino to trigger a servo to hit the Esc key on the CNC keyboard (which in turn would trigger Mach3 to shut down the CNC). There were a few problems with this. 1) I have to wait for the Network shield to come from China (about a month or so), and I did not want to run a lengthy network cable from my router in the basement into the garage. An Arduino WiFi shield was also out of the question as they are costly.
Then it hit me.. The Foscam has the ability to remotely trigger the IR LEDs to go on or off. I managed to trace the signal wire to a wire on the mainboard that goes HI (1.5V) when the IR LEDs are on, and LOW (0v) when off. Voila! Tapping this signal then bringing it out to an ATTiny85 with a bit of simple code, I could control a servo connected to the keyboard.. So, onto the Arduino IDE, and out came the soldering iron. A few hours later, here we are.