Clap and Wash Project With #microbit !

Washing hands with soap and water is the best way to remove all types of germs and chemicals off our hands. Taps are common handwashing solution in Nepalese households but it is important that we don't touch the tap back again with clean hands after we have just finished washing.

Apart from that, we don’t even realise how much water we waste when washing our hand. The tap is left running whilst the essential lathering of the soap and scrubbing of the hands takes place.

Here is a small demonstration of how washing hands with soap water can be made more effective using a microbit. A micro:bit, a simple code and some equipment can make handwashing go completely automatic, touchless and conserve water (#SDGgoals). More importantly, one can make sure he/she scrubs hands for 20 seconds. #GlobalGoals

A microbit (V2)

Two Submersible Motors with pipe

One Gear Motor

Three Channel relay

Power supply to relay

Power supply to motors

Three Pins of Micro Bit were connected to three channels of a relay (works as a switch). 3v pin is connected to vcc of the relay. Relay was used because, a microbit cant drive all three motors on its own as much more current is drawn from the microbit than its capacity. Separate Power Supply was given to the relay because a microbit can't handle current drawn from relay and motors. Submersible motors were used to pump water and soap, another motor was used to drive tissue motors.Motors have separate power supply.

Code was written and uploaded to microbit. Microbit (V2) has a inbuilt mic to detect sound. The code was set to detect sound from the environment. If sound intensity reaches the level, it enters into the rest of the code. The programme has four functions which was used to start respective motors for certain time as required. Functions (water, soap, wipe) in the code starts one motor and closes other two by turning pins to high and low. The pin with low signal turns relay channel high (as relay is a active low device) thus pin with signal low(0) turns the respective motor on. The Function "reset" makes all pins on microbit to high (1) so all channels in the relay is low hence all motors are closed. Reset function is called after the washing is over. Rest function is also called to let user wash their hands for 20 seconds. During that period One led glows to represent one second to let user know the timing.

After the setup was done, components were connected and coding was done. The automatic hand washing device was ready. One who wants to use it, can now just clap once near to the mirobit. The code activates pin to submersible motor (submersed in water) through the relay to pour for 10 seconds to rinse hands. Motor submersed in Soap solution activates immediately after rinsing is done for few seconds.

Now, all motors stops pumping. The system lets you to lather the soap and scrub for 20 secs. Each LED light on microbit glows to represent one second and by the 20th second all first four rows will be filled. One 20th LED on microbit keeps blinking to tell that would the finish line.

Once scrubbing is done, a pump pumps water for sometime to wash lather off hands. After, the geared motor rolls to roll out few tissue to wipe after washing.

Now, as a "touchless washing" is done, the device is now ready again for another wash until another dirty hand claps again.