Lee's project

[hotpoint95622]

It all started when I came across a book on micro-controllers in Maplin called PIC in practice by D W Smith and is a simple project-based approach , the aim of the book is to teach you how to build control circuits using devices such as switches, keypads, analogue sensors and LED‘s, and so on. The PIC has timers and input, outputs. After a few weeks of working thought the book I hit on the idea of making my own washing machine control PCB using the 16F872 micro controller. I then started to work with some electronics books to teach myself how to use circuits to interface with the PIC (micro-controller) so that the outputs will work relay. PIC used 5V DC and relay use 12V DC and switch 240V AC to operate the machine components (pump, valves, motor) It has taken about 8 months to get to this point as I am total self taught and have made a lot of mistakes and found out the hard way.

So the program is complied in the software which comes with the PIC program board which connect to the office PC via the serial connection, the software converts the ASM file (assemble file) to the machine code which is then transferred to the chip (PIC).

The PIC is separated in to ports, which can be set up as an input or an output.

Porta 6bit = 6 input or output
Portb 8bit = 8 input or output
Portc 8bit = 8 input or output

 

[hotpoint95622]

I have complied my program which look like this

;========================================================================================
;PROGRAM STARTS NOW
;========================================================================================

SW0 BTFSS PORTA,1 ;SELECTS WHITES 90c
GOTO WASH90

SW1 BTFSS PORTA,2 ;SELECTS COLOUR FAST 60c
GOTO WASH60

SW2 BTFSS PORTA,3 ;SELECTS NON COLOUR FAST 40c
GOTO WASH40

SW3 BTFSS PORTA,4 ;SELECTS DELICATE & WOOLENS 40c
GOTO WASH30

SW4 BTFSS PORTA,5 ;SELECTS LAST RINSE AND SPIN 1000rpm
GOTO H
GOTO SW0 ;RECHECK SWITCHES TILL ONE IS PRESSED

;========================================================================================
;WHITES 90c ( 12 SECOND WASH WITH 6 SECOND WAITE )
;========================================================================================

WASH90 BSF PORTB,0 ;SWITCH ON DOOR SAFETY LOCK
BSF PORTC,7 ;SWICTH ON HOT WATER VALVE
BTFSS PORTC,0 ;CHECK PRESSURE SWITCH
GOTO WASH90 ;REPEAT ABOVE TILL WATER REACHES FULL LEVEL

BCF PORTC,7 ;SWITCH OFF HOT WATER VALVE

CLRF COUNT
MOVLW .6 ;SET COUNTER TO 6
MOVWF COUNT

A BSF PORTB,2 ;WASH ACTION CLOCKWISE
CALL DELAY12

BCF PORTB,2 ;STOP WASH ACTION

CALL DELAY3
BSF PORTB,3 ;SWITCH ON CHANGE OVER RELAY
CALL DELAY3

BSF PORTB,2 ;WASH ACTION ANTI CLOCKWISE
CALL DELAY12

BCF PORTB,2 ;STOP WASH ACTION

CALL DELAY3
BCF PORTB,3 ;SWITCH OFF CHANGE OVER RELAY
CALL DELAY3

DECFSZ COUNT
GOTO A ;REPEAT ABOVE FOR 6 CYCLES 12 WASH ACTIONS

The basics of the program is to check the inputs and then move to the next instruction or repeat the last till the input is clear then move onto the next instruction to set the output and then Waite the amount of time in the delay before executing the next instruction to clear the output and so on.

Key:-
BTFSS bit test file skip if set (check input if it is set (on) skip to next instruction)
GOTO go to label stated (go to the label on the left and continue)
BSF bit set file (switch on output)
BCF bit clear file (switch off ouput)

If your think of trying this out it is best to start with the book I have used and work thought.

Photo of chip in program board connected to office PC

 

[hotpoint95622]

More to come when I have found a suitable host machine, I would like to find a hotpoint 95

 

[Unimatic1140]

Very interesting Lee, I'm interested to see the interface you built between the computer and the washer as I have done something very similar with my Super Unimatic Washer.

 

[hotpoint95622]

Lee's project

Hi, there is no interface between the computer and the washer, once the chip is programmed it works alone, I have build a circuit board to hold the chip and it also contains the circuits to interface with the 12V DC relays and the inputs from switches, pressure switch for water level and 2 stats, one 90C and one that is 40C/60C I have built a power supply to feed the PCB and the relays with DC and these will operate the 240V AC components, so once programmed will not need to be connected to PC.

Photo of PCB with chip installed note: connector with red LED’s are outputs to relays and the group in the top left in rows are inputs from switches and pressure, stats.

 

[hotpoint95622]

Lee's project

Photo of 12V DC power supply for PCB

 

[hotpoint95622]

Lee's project

Wiring digram

 

[Unimatic1140]

Very interesting Lee, I'm impressed. What do your relays look like?

I don't know if you have seen the pictures of the washer I built using parts from vintage and modern machines alike. I added two way communication with sensors that communicate back to the computer from the washer...

http://automaticwasher.org/cgi-bin/00ShowCollectionGETD.cgi?dir=/COLLECTIONS/_SUPER_UNIMATIC_2009

 

[toggleswitch2]

YAY WAY COOL.

Now a similar item to function as a vintage dishwasher "timer" and we may approximate a DW that actually cleans!

 

[vivalalavatrice]

oh guys... I did...

something of similar...

http://www.plcforum.it/forums2/index.php?showtopic=48651

 

[vivalalavatrice]

and here you are the result....

.

http://www.plcforum.it/forums2/index.php?showtopic=48854

 

[vivalalavatrice]

then...

Very very much congratulations to your project Lee, it seems indeed better and goodlooking than mine...

They're in Italian but here you are the features of my machine

http://vivalalavatrice.blog.tiscali.it//Nuova_Superautomatica_1953480.shtml

 

[vivalalavatrice]

.... and of course...

IT WORKS!!!

<object width=425 height=344><param name=movie value=></param><param name=allowFullScreen value=true></param><param name=allowscriptaccess value=always></param><embed src= type=application/x-shockwave-flash allowscriptaccess=always allowfullscreen=true width=425 height=344></embed></object>

Bye
Diomede

http://it.youtube.com/results?search_type=&search_query=Nuova+Superautomatica&aq=f

 

[wiljan]

That is so cool! I wish I could do that!

 

[hotpoint95622]

Lee's project

The relays.

2 on the left of photo are for motor isolation and armature change over, 4 in the middle are for motor speed selection which I will talk about later and the last one on the right is a 30A relay for the water heater.

 

[hotpoint95622]

Lee's project

The Solid stat relays ( triac ) to control water valves and the drain pump which are all low ampage, this board is opto-isolated from the mains power and has it’s own power supply. No moving parts to ware out like relays.

 

[hotpoint95622]

Lee's project

The speed control of the universal motor, a bit of a cheat, as this is a Hotpoint unit that will go nicely with the Hotpoint motor I have acquired. Don’t forget that the heat sink on this type of unit is, one, very hot and, two, LIVE, and will BITE like a pit-bull bog.

 

[hotpoint95622]

Lee's project

Basic wiring diagram for the speed control and motor, speed control unit is a simple comparator module which increases power or decreases power by the voltage sent from the taco generator on the back of the motor, change over on this Hotpoint set up is achieved by the field windings, which I thought was odd as the other units ( Bendix ) I have change over the armature instead.

Can’t Waite for the motor to arrive so I can play.

 

[hotpoint95622]

Lee's project

I would like to than Tom (hotpoint9534) for sending some wiring diagrams and anyone else who has contributed to this project?

Photo of back os speed control.