A pool cleaning robot custom electronic based on AVR ATmega8 microcontroller

Chlorine damage a gasket on the robot and cause the shorts of the electronics embedded. It is obviously out of warranty, and the manufacture does not send me any information to repair it, moreover a new board will cost me more or less like a new robot, cause I’ve to sent it to a certified repair center. For information only, original board was based on a ds Pic.
So, i decided to get it back to life, replacing the electronics that gets damaged.
My replacement electronics it is based on ATmega8 micros.
The project is divided into two parts:

  • timer
  • cleaning robot

The timer contains the 220 AC to low voltage DC current, and it is out of water, his purpose is to start and stop the cleaning pool robot, which of course is inside the swimming pool.
The timer is an ATmega8 based countdown programmable timer, it is like the one you can find here: http://davidegironi.blogspot.it/2013/10/an-atmega-countdown-programmable-timer.html
It alternates a “working” period, and a “pause” periods. So i can run the robot at a predetermined interval of days, for an amount of minutes you can chose. Let’s say for example 30 minutes every day.

It shows time using a double seven segment display. Periods can be selected from predefined values, stored in the firmware.
There are five buttons:
A pool cleaning robot custom electronic based on AVR ATmega8 microcontroller
  • pause +/-: select the pause period
  • work +/-: select the working period
  • start and stop: iterate through periods.
Both period are stored into internal avr eeprom, so that if the main power goes down, user settings are restored at next boot up.

green led indicates that the robot is working.
red led it is used for over/under current detection: Indeed it may happens that something goes wrong, maybe one motor of the robot does not starts due to dirty. The timer checks the current consumption and eventually stops the working period, until the next iteration.

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