My first foray into robotics was dissecting a friend’s remote control tank and trying to stick the wires into the printer port of my Amiga 1000. Suffice it to say, it didn’t work.
Before you get too excited, this isn't the kind of robotics involved in exploring Mars or terminating the human race. This is just plain old household automation and remote control. Some day I may try and build an artificially intelligent army of bipedal mouse hunters, but you have to start somewhere.
Recently I’ve been able to afford the fancy technic LEGO with programmable motors and sensors, and also explored the Arduino circuit boards that can be programmed with an infinite selection of LEDs, sensors and motors to create anything you can imagine.
Using LEGO and Arduino, and using whatever components I could harvest from an old remote controlled drone, I attempted 3 projects:
- Little RC Tank
- Remote control switch for my fireplace
- Automated control of my venetian blinds
1. RC Tank
This RC tank used a set of tracks from Tamiya. They are easy to build and have their own gears and motor for a simple steering system. I stacked an Arduino processing board, a motor control Arduino board and even incorporated RC control from my old Walkera drone. I was even able to connect the video camera so I could watch where the drone was going on the small screen on the radio controller. The Arduino required programming to interpret input from the RC controller, and my math wasn't perfect; the tank never moved straight. With more testing I'm sure I could have gotten it to work, but I was impatient and decided to move on.
2. Fireplace Control
The second project I wanted to tackle was a remote switch for my fireplace. Most fireplace switches are low voltage and low tech; just two wires that need to be connected for the fireplace to turn on. Older ones are just a rocker switch. Without power and a third neutral wire, the switch usually can’t even power a remote switch itself. I tried installing an infrared controlled Lutron switch with no success. I had to get more creative!
My first solution was to use a Arduino board with a custom made circuit board that could receive IR signals and was programmed into my universal remote. It worked, but the IR code I used was often confused by other signals used by the TV and cable box, so the fireplace tended to turn on and off randomly. Not ideal in warm summers and cold winters!
The next solution was to use a LEGO motor that flips a switch to connect the circuit and turn on the fireplace. LEGO has its own system of remote controls and sensors, but it doesn’t have a simple relay. In other words, you can’t just flip a switch with a remote control signal from a LEGO remote. So, I built a geared motor that flipped a standard electronic switch. It worked great but was not purely on/off. You had to wait for the arm to move over and actually click the switch, but it did work. Eventually I unwired it because it was ugly. The LEGO device had to sit on a shelf, it had a power transformer that needed to plug into the wall, and it was incompatible with my Logitech universal remote. Overall, not ideal.
Long story short, if you have a better solution, please let me know!
3. Venetian Blind Control
This was probably the simplest and most successful project. I stuck to LEGO, so I just had to glue a LEGO motor and remote control sensor to the inside back of the venetian blinds cover, and affix a gear to the knob that a 'wand' usually attaches to. The metal loop had broken off, so it made it pretty easy to slide a gear on. I used a worm gear to drastically increase the power of the motor. It twists slowly but with lots of torque. This system worked well, but is noisy and a bit slow. I wish LEGO would make stealth motors!