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Thread starter #1
Hi all, I am completing modificatin of a laundry washing machine to be mass produced and need electronics to switch on/off at two stages hours apart. With my decipline, nuclear power engineering I am like allice in where is this land. I was told I need microprocessors, redirected to this forum.
Obvoiously wih least buttons to operate.
The requirements are
1. With the !id closed( a switch at the lid) ,
switch on to turn the motor on and run for period T1 and turn motor off as time period ends.
2. Stay off for period T2, regardless of signals from lid switch.
3.Turn motor on and stay on for period T3, with lid close.
4. Turn finish signal on thirty seconds following end of T3.
Depending on cost, Electrically dead of 230 volt current at the end.
I am at level zero and need all advice to select the right microcontroller, if that is indeed the right choice.
Regards joe


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This sounds like an ideal job for an Arduino. I suggest you buy a Arduino Uno and go through some of the tutorials available on how to use them.



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Will look into the microcontroller and report back.
You can get a software person to write the program but probably you can do it.
You should down load some example programs and see if it works in hour head.
Every micro is a little different and every development tool is different but:
Usually there is a "blink a LED" program. ***every system uses slightly different words***

First you need to agree on some things.
LED = pin-7; you can say"pin-7" every time but "LED" is easy to think.
Off=0; Depends on if the LED comes on when the pin is high or low.
Write the program
Wait 1: do nothing for 1 second
LED = on
wait 1:
LED = off
jump to start

Also you need to look at "timer" program. (or delay)
If you can see how those programs work you are part way there.

I see you need to test two things. Some thing like:
If lid = closed and timer2=on then (do first thing) else (do second thing)

It looks like you need to understand three demo programs and use the pieces.

If you have question just ask. Please include as much information as possible. (what micro-computer?)


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yes very simple for a microcontroller , just check for enough pins for switches and sensors.. and round up for future design updates!
also you need a pin AND "250v relay" for each motor you are controlling
Thread starter #6
Thanks for your response and advice.
A microcontroller, 250 volt relay switch and some pins wont squeeze the budget much and plenty room to place them out of possible water leakage. I am still left with enough funds to ask for electronic engineers to be invited to join us. I overestimated the cost initially, thanks to you and all those who assured me of less expense for the electronics.
Thread starter #7
The logic is like forturan I use to use thiry six years ago. I got an idea now of what you are saying.
Thanks to all
Regards joe


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What a strange (too simple) machine is that!
Thread starter #10
This will be improved version of machines widely used in domestic market already.
Iranians don,t blieve, public laundries are in actual use in the west and dismiss the idea of public laundries on sanitary grounds, kinda like public tooth brusn.
No laundry dryers here either.


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If T1-T3 are user adjustable, you might need some sort of user interface.

See www.picaxe.com for a BASIC programmable processor based on the PIC.

I/O modules are a safe way to interface signals such as the presence of 240 V to logic levels.

The power supply you can buy rather than make.

With the "high-level" programming that some systems have, it's tough to get the systems into deep sleep. Limits have been imposed for quiesent currents in some jurisdictions.

Watch 3.3 and 5V interfacing. If it's a standard induction motor, you would likely be calling the relay a "contactor". A "contactor" is a definite purpose relay.


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BASIC programmable processor based on the PIC
There are a number of BASIC options for programming. Real programmers laugh at BASIC; but it is simple and easy to learn. I use PIC BASIC PRO which is harder than PICAXE. If you are looking at buttons/switches and turning on/off some thing BASIC is real simple.
Thread starter #13
Thanks for your response and advice.
The long, motor off time period, is a neccessity, it is what appeard dounting from the begining. The controller would be on stand by, that would be regardless of how many times the lid is opened or closed.
Naturally kids stay away from anything that sounds runing or adults wouldn,t stick fingers in, so the machine is to be electrically dead of dangerous voltages during long time period of motor off. The rest I can alter to lower the cost.
Looking forward to receiving your opinion.


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I consider myself a real programmer having programmed games for over 30 years and I consider Basic a real language. I do however prefer C.

Thread starter #15
Adjustabilities, is to make wider options available.
T3 the final run is important yet can have a single value, dose not have to be user adjustable.
Neither dose T1.
The operator will load add detergent and lets water fill in, turn the machine key on and leave.
Motor runs for T1 then motor off .
T3 starts several hours later and when ends, motor off, turns finish signal on.
Next all off.

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