Washing machine, dishwasher and other machines operates at high voltage. Take precautions and always be careful. Wrong decisions may result in DEATH ! Main board of the machines include high voltage even on a simple button.
There was two main problems:
- Odor comes from wet clothes stayed inside the machine for a long time (6 hours?)
- Noise of the machine
To overcome this problem, I simply set up a timer for the machine.
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Short press will increase waiting time by one hour.
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Long press will reset everything.
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7 segment display will show remaining time. Uses hexadecimal notation.
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When timeout, machine will be triggered by relay. (Same thing as pressing start button for 1 second)
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Designed finite state machine is located below:
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PC
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A washing machine or a dishwasher which doesn't have timer function
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Arduino UNO and USB cable
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5V Relay (for controlling 110V / 220V)
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7 Segment display
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Button
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Wire, soldering iron, insulating tape, zip tie, hot silicone glue, insulating glove, voltage tester pen etc.
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A lot of caution (for staying alive)
Take insulation precautions before starting !
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Install required libraries:
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Connect Arduino, relay and 7 segment display together. Pin configuration located at
CONSTANTS
section in source code. Relay must be connectednormally open
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Test configuration with uncommenting
//#define DEBUG
line in source code.
- Cut off electrics.
- Take of the main board of the machine.
- Locate start button and solder wires to it.
- Put back the main board to the machine.
- Connect wires to relay.
- Fully cover the relay with hot silicone glue. Do not left empty area.
- After silicone glue gone solid, cover it with insulating tape.
- Bind fully covered relay to a corner inside the machine using zip tie. It must not fall off.
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Turn on the electricity.
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Test every touchable/untouchable area with voltage tester pen.
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Test arduino pins related to relay. Also test relay pins.
- If you left DEBUG line uncommented, you can test now. Press few times and wait.
- When timeout, relay will close circuit for 1 second.