This week, we're offering you a simple post on a topic we love but haven't covered in a while: Enhancing everyday objects with Yoctopuce modules. Do you remember the little video we showed you a few weeks ago about timing a radio-controlled car?
At one point, the car passes through a small layer of fog/smoke.
Fog on the Yoctopuce premises? weird...
This "fog" is generated by a small fog machine, but we soon realized that we couldn't afford to leave it on for the whole video shoot. On the one hand, we'd quickly smoke the whole place, and on the other, if we overdid it, the smoke would leave a sticky residue all over the place. So we quickly decided to remotely control the fog machine so that it would only switch on automatically as the car approached.
The fog machine
After a quick inspection, it became clear that the construction of the fog machine had not been designed to be easily reversible. In any case, we didn't really feel like dismantling something full of oil. On the other hand, the machine comes with a simple radio remote control for remote activation. It's not very practical, with just one button that you have to press for about a second to start the fog machine, and then press again for a second to stop it. But it works quite well.
The fog machine comes with a remote control
We took this remote control apart. The top part is actually a plastic film that's easy to peel off. Inside, there's just a PCB with a few radio components and buttons printed directly onto the PCB. Clearly, this PCB is a generic part intended for several uses, as there are 21 (!?) buttons, whereas our remote uses just one.
The inside of the remote control
So we simply soldered two wires to the tracks leading to this key, and connected these wires to a Yocto-Relay, inserting a 3 kΩ resistor to emulate the key's resistance. The relay is thus wired in parallel with the key. We installed the Yocto-Relay in a box glued to the back of the remote control box and reassembled it.
Small modifications to the remote control
The result is a remote control that's still functional: it still triggers the fog machine when you press its button, but now it has a USB interface so it can also be controlled from a computer. We made a short video demo.
In just a few tens of minutes, we've transformed a simple little manual device into a machine that can be controlled from a program running on a computer. You can't imagine how cool it is to work at Yoctopuce :-)
