WPC. Thought that has become a thing

Tracing a story of little homemade device

The idea, development, assembling – Vadim Loginov

Once I faced a necessity of a device for controlling water pumping. The thing is that I had to turn on the pump and check water level every 20 minutes. After water goes down I had to turn the pump off to prevent its damage. But it is very annoying... Thanks God, I am automation engineer! I decided to make a simple device which would do this check work for me. So...

Goal – device for automation of home "dewatering plant" (it sounds too serious...)

So, what should I begin with? I think the best is to determine what must do out device (let's name it WPC, device for water pumping control)

WPC functions

• turn off the pump when water level is LOW
• start working after determined delay
• continuous level monitoring
• indication

A structure chart of WPC is shown on fig.1.

Figure 1. The structure chart

There are several functions. But how should the WPC behave to be able to execute them all?

WPC operation modes

• Timer mode. WPC starts working after time delay is passed. If a user sets a zero delay, WPC will start working immediately
• Repeat mode. WPC checks the level every N hours. It the level is HIGH, WPC will start pumping

Algorithm

Well, let's see how WPC will "think" while doing it's job (fig.2)

Figure 2. The WPC algorithm

Circuitry

I've chosen ATtiny26 to be the heart of WPC. 7-seg LCD indicator is used to indicate "hrs" and making "pumping" animation.

Figure 3. The WPC circuitry

And PCB, of course. See fig.4

Figure 4. The WPC PCB

Practical realization

In next pictures you will see all steps I accomplished to make a circuit board for WPC

Almost done! Let's see how do out activities correlate with a structure chart mentioned before

Figure 5. Almost ready for assembling

Did I forget something? Oh, of course! Our microcontroller is not "alive". The program! I'll write the program in AVR Studio. You may see the code in the listing.

Done! The final result is shown at fig.6

Figure 6. Here is out new device

Demonstration

In order you to look how this stuff works I made a short movie (link here if there is no video below)

Well, it's time to say goodbye. Thank you for your interest and patience. All the best!

© 2010 Vadim Loginov