Change a microwave dial into a keypad?

[Nathan323]

Hi all, I'm new to electronics, am a 2nd year apprentice electrician. Have a microwave that has a dial for input that is too sensitive and therefore it is time-consuming to select options accurately. Found this http://hackaday.com/2011/06/09/repairing-a-broken-microwave-keypad/, and this http://www.instructables.com/id/Replacing-a-membrane-keypad-with-microswitches/?ALLSTEPS, wondered how a dial works compared to this, would I be able replace the dial with a keypad?
I am more than ready to learn how to do something like this every step of the way properly and safely.
I'm not interested in buying a new microwave, and I don't care if the cost of the tools/parts are more than a new microwave, I am in this for the challenge.

 

[Alec_t]

Welcome to EP, Nathan!
The dial is just a rotary mechanical time-switch (Google should be able to find you some examples).
This isn't what you want to hear, but I would caution against messing with a microwave oven. It produces enough microwave energy to KILL you, or cause a fire if the control circuit fails. You should also consider whether your household insurance would cover you/your property if the modification resulted in a fire/accident.
I'd suggest you cut your electronics teeth on a safer project.

 

[Nathan323]

Hi, thanks for reply.
I'm going to give this a go, if its actually possible. I am well aware of the dangers of electricity, as I am a 2nd year apprentice electrician. I will not be rushing into this, I will be slowly and methodically learning how to do it properly and safely.

The dial isn't a rotary mechanical time-switch, it is a dial for input - when you turn it, the digital display shows increments of time increasing or decreasing. You then push the dial like a button, and it starts the microwave on the selected time. It is too sensitive and therefore it is time-consuming to select time accurately, then when pushing the dial to start, the dial often moves slightly first, changing the preferred time. I am wondering how the dial interacts with the matrix (as shown in the 2 links), as opposed to the keypad.

 

[Alec_t]

Ah, that sort of dial . Probably just a shaft encoder which the system micro reads. So your keypad scanner would have to emulate the encoder output.

 

[Nathan323]

Ok thanks for info mate, I'm going to look into this over next couple weeks