It was October and I was looking through the Make magazine website and saw all the various Halloween projects.

With one week to go before Halloween,
I thought I should make something for Halloween.

The challenge was to make a quick Halloween prop in a weekend.

Mission Impossible?

“Your mission, should you decide to accept it…”
I thought what could I do in a weekend? A quick trip down to the local
supermarket and purchased a Halloween pail.
A week before Halloween the choice reminded me of the reaper (Grim).

I drew a quick schematic of what would be needed. I started looking
through my boxes of parts and found a spare ISD25120 this is a (2 minute) voice recorder.

A sensor was needed and I found a light Dependant resistor (LDR) and
thought I would use that to sense people putting their hand into the candy pail.

I knew I had Picaxes available and I only needed a Picaxe 08
because this was going to be simple.

How will it work?

The design is simple a small amplifier IC, a picaxe microcontroller and
the ISD speech IC.

When a shadow is cast over the LDR a pulse provided by the Picaxe triggers the ISD25120 to play
the next track. (See schematic)

This was not that complex so I found some strip board and started making
connections.
I recorded various scary noises

Once everything was tested I drilled some holes at the bottom of bucket.
I found some rubber domes. The type you put on kitchen cabinets. Some hot
glue was used to secure the speaker, switch and LDR.

The location where the bucket is very dependant on light and should be placed so that under normal circumstances there will be light on the LDR and taking candy always casts a shadow

 

But not bad for a weekend project – ideas for the future.

• Add an ultrasonic sensor instead of LDR
• Hide the sensor in a better location

Total cost was about $25 but seing I already had some parts I actually spent about $12