Difference between revisions of "Cheesoid"

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I need speakers!
I need speakers!
An MP3 shield is a fine solution but it's not my cup of tea: too easy and no pain!
Other devices can play audio and MP3s: PDAs, phones, etc.
== Movement and Power ==
== Movement and Power ==

Revision as of 12:20, 2 June 2011

"Why Cheesoid exist?"

Mitchell & Webb: Cheesoid

An unhappy robot designed to have a sense of smell but can only distinguish between its two operating modes: "CHEESE" and "PETROL".


Everybody loves robots: It's your plastic pal who's fun to have around! I'd like a robot too, and I'm going to build one goddamnit!!!

As with everything I want to build, it must be funny, and so Cheesoid is the ideal blueprint to follow.

It has (should have) speech limited to a number of pre-recorded phrases: -

  • "Cheese"
  • "Petril"
  • "Help! Cannot see! Can only smell!"
  • "Why Cheesoid exist?"
  • etc.

Basic Construction

I have a cardboard cylinder (slightly smaller than the original) and a silver "nose hose". The nose hose will contain a bent rod that will be rotated by a servo or stepper motor. The robot can run on top of a R/C car to begin with. The donated R/C car at the space has no battery and I couldn't get the motor to run!

I plan to cover Cheesoid in silver-grey paper.

The nose hose needs to be mounted in a shallow box which in turn is fixed to the body.

The "CHEESE" or "PETROL" mode switch must be authentic!

Voice capability will just be some sort of recordable button box.

Object detector (that initiates the smelling process) would be awesome.

The ability to actually distinguish between the smell of cheese and petrol would be crazy-awesome!

Need: -

  • R/C vehicle
  • silver-grey paper or card
  • nose rod and motor
  • voice
  • lamp eyes - one red, one green
  • flashing LEDS
  • automation!!!

Nose Stepper

A stepper motor will be used to drive the "nose". The curved nose hose is fixed to the body and doesn't rotate. Inside a rigid but bent rod will rotate, driven by the stepper. The stepper needs enough grunt! I have no idea how "grunt" is measured in ISO units - torque I guess. Speed and accuracy is not so important for this task but it is a learning experience.

So I chose a random biggish stepper motor (from the members' motor box)...


It has 6 wires that go to a 2x4 0.1" pitch connector. It says "MINEBEA" "TYPE 17PS-C035-03" -- hmmm...

1.7 inch, P = Precision, Hybrid, S = 3.6 Deg, C =2 & 4 Phase Hybrid, Motor Lengths = 0(?), Different Windings = 35, Version = 03.

OK, so the information on the side isn't much help in finding the voltage and current so using the magic knowledge on the pages listed above I gleaned some info using SCIENCE!!!!

The stepper turns out to be a Unipolar. It has 6 wires, 2 for the centre taps which should go to V+ and two each for the grounds of the half coils.

I identified the usage of the wires using my cheap multimeter and measured the half coil resistances: 36.9 ohms, 36.6 ohms, 36.7 ohms, 36.7 ohms.

Six wires
Brown Black Red
Green Orange White
Wire purpose
Coil B 1 Coil A Centre Coil B 2
Coil A 1 Coil B Centre Coil A 2

To be continued!!!

Display and Indicators

The eyes on the "real" Cheesoid just flash left-right, left-right with one eye being red and the other green. I'll stick with this for now as it's simple but I'm not sure I want to use two pins on my Xino. I'll look into that when I have the basics in place.

I have added an LCD display...

Why Cheesoid Exist?

This is a Seiko L2012 LCD module (File:Seiko L2012 LCD Module - datasheet-3.pdf) which can be driven straight from the Arduino example library. I modified a Xino to directly drive one with a 14-pin header soldered to the prototype area of the board. This module I rescued from the skip at work and it has some damage to the LCD but it is entirely usable.


I need a device that can play back my recordings on demand. Some sort of controllable MP3 player would be ideal. How do I make an MP3 player controllable? Wire into the buttons? Possible. I'd need some feedback on what's playing or whatever is useful or available. I could try to read the LCD screen! I could try to "listen" to the audio output!

I need speakers!

An MP3 shield is a fine solution but it's not my cup of tea: too easy and no pain!

Other devices can play audio and MP3s: PDAs, phones, etc.

Movement and Power

Although I eventually want the robot to be pretty autonomous, initially I guess any kind of movement will be good. I imagine simply mounting the body on a reasonably powerful R/C car or tank. I'm going to have to get to grips with servos and R/C in general. I'll be looking out for tank track parts (e.g. bike chain tracks) in the meantime for a more serious robot movement base.

For power I want to try out using some of the 12v and 6v lead acid batteries from the Emergency Roadside Telephone. I have recharged a 12v one and it seems quite happy after being sat on a shelf for many years! I also have my solar panel and I'd like to make use of it for recharging.

--Michael Erskine 16:38, 3 May 2011 (BST)