Sensor Drying

I decided to up the temperature as my last test took a long time.
I updated the code to transition state to cool down when difference becomes latter than 50

The full sensor also works, which is what caused the transition to heat after I emptied the tank and restarted.

Sensor Drying

I don't know what the yellow wire does,  but I cant seem to see any sensor hardware.
But I do have 2 temperature sensors.

I did a bit of research and there was one page that suggested that you could use a single sensor and imply how dry the clothes are. In theory as the cloths become dryer they heat up and cool down quicker.   Something like that.
My numbers did not seem to show this.

What I did notice was that the differential between the two sensors increases as the closed become dryer,


  

That would explain the tingles

Arduino Tumble Dryer State machine

Its simple.
I'm not sure if this is quite by the book.   All three states in the yellow box can lead to FULL or COOL_SPIN
Pressing the button on the machine cycles through ready, run and cool spin.   What more do you need?

you can get the code here :
http://jtumbledryer.blogspot.co.uk/p/pins-define-motordir-5-define-motoren.html

Ethernet strads

Damn it!  one of my wires has come loose or snapped.
Ethernet core wires have a habit of snapping and soldering in almost sub zero temperatures results in poor results.

I think I get me some modding wire, or wire wrap stuff

Arduino Resets

One little problem I am having is that when the Motor starts or stops, It can cause the Arduino to reset.   To avoid this,  I have initially remove the code that reversed the direction  every minute or so.
This is not caused by switch the relays as I have tested this and all three seem to happily switch without issues.

Today I made a couple o changes.   I moved the arduino away from the Motor relay and have added a 10uF electrolitic and a small 10nf ceramic across the arduino power.  ( I probably need a 0.1uF ceramic capacitor but I dont have one to hand)

This seem to have help a little,  but not perfect.


Oh,  and it seems the arduino is not compactly isolated from the mains.  The USB cable was a tad tingly


useful info here:
http://electronics.stackexchange.com/questions/101815/pic16f628a-resetting-after-relay-turned-off/101879#101879


Someone else has done something similar here and has included a stabalizer

http://www.instructables.com/id/Repair-and-Upcycle-Defective-Dryer-With-Arduino/?ALLSTEPS

Success My clothes are drying

Although, I have not fully worked out how to do a sensor dry, but I have an idea,

Controlling the LEDS

The transistors on the left control the three relays.
The LEDs are controlled in pairs ( coloumn) so you are a little limited but its sufficient to make silly little patterns.
I'll draw a little diagram at some point

Initial tests

Only have 3 relays and one NTC sensor connected.   I added a 20kohm pull down resistor on the NTC,  but the board already had a 5k on board,  so in hindsight I'll use that.

The relays are controlled with a high side PNP transistor ( A8A ) which in-turn is switched with a NPN (A6A),  this is nice an easy to intercept.
It was easy enough to track the circuits and probe for places to tack a connection to.

New microcontroller hot glued onto the old board

Hot 

I concede defeat

I give up.   After drawing out a circuit myself,  cross revenue with a diagram I found on the Internet which doesn't match my diagram,  I decided to strip off everything.
This is crazy.    Why have they connected the  +
-5v to live.   Actually,  why he -5v, -12v and GND.

The circuit diagram that does not match mine:

Power up with a PSU

I though I'd try and power up the board with a PSU.
I hoped to see some life,  some LEDs lighting up.   Something

Take this

Surely this bad boy will hold up.
No.... It went pop too

Dirty hack

So I didn't have the exact value,  and I only had quarter watt resistors.    I thought this might work for a bit.   Like a few seconds.
It  didn't,  it went pop.

Burnout resistor

Upon close inspection,  I spotted this burn out resistor.   Hmm,  I think another trip to maplin is in order

All soldered on

Unfortunately this has made no difference at all

Speculative fix #1

56p spend on a handful of new capacitors.   I thought I'd give this a go and see if I have any luck

Hoover Condenser Tumble Dryer VHC 691B

So it's dead
No power, no lights, no spin, no nothing.