Hand Gesture Power Socket

Firstly, the concept is pretty simple

The hand gesture module XC3742 detects what the user is trying to do and sends a matching command to the wireless transmitter. That transmitter then activates the wireless power socket.

Likewise, the connection diagram is almost just as simple:

All we are doing is connecting up the gesture sensor exactly how it asks to be set up via the I2C protocol; The 433Mhz wireless can be connected anywhere, but we kept it on the same side as the other connections to keep things tidy.

We used a breadboard in our build, but you can use anything to connect between the pins of the hand gesture module and the UNO. If you haven't got one before, it's a good oppertunity to have a look at getting the XC3902 kit as that has a lot of the bits and pieces you might need every now and then.

One thing about connecting these sort of prototyping wires is that they can sometimes fall out, which can be a real problem out in the field. If you are building something a little more longer lasting, you might want to look at learning how to solder and soldering things together, or use something like screw terminals to contain everything.

If you come into the store this month (November 2020) you should be able to see this on display soon, come and try it out and pick up a kit while you're in store, plus whatever else you think you might need.

Programming is also just as easy. Open up the Arduino IDE and load the provided wax-on.ino.

For this we need just one library, so you can open the library manager (Tools > Manage Libraries) and install the "Gesture PAJ7620" by Seeed Studio. Then you should be able to select the Port for your arduino, and ensure that the Board type is set to "Arduino UNO"

The RF socket is easy, as there's no need to log in, nor do you need any wifi or otherwise.

1. Connect up the RF socket into a powerpoint. You should see that the LED indicator on the socket will blink slowly.

2. Use your project to send it a command. It should either click solid on or solid off, depending on the command that you have used.

When the RF socket blinks, it will accept and latch onto the first valid command it can hear. That's why when the RF socket is blinking, you are meant to wave your hand over the gesture sensor module just as if you were using it for real. Once the socket accepts that command, it will remain "bound" to the gesture sensor. If you disconnect the RF socket you will lose the pairing, but you can just follow the same instructions again to re-pair.

You should just quickly and confidently swipe your hand over the sensor for it to pick up the gesture

• Not Detecting

The distance only needs to be a few centremeters up, we've been able to get it to almost 10 cms though, so there shouldn't be any problem with detecting your hand at a distance.

Check the serial monitor, it should tell you what it is doing. One issue could also be the delay in between detecting the gesture and sending the signal: you might have to wait a short while for the signal to be transmitted. This can be fixed in code and we're looking forward to a pull request on github.