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Zeaker2 - by David Buckley February 1984
Expandable Turtle controlled over an umbilical from an host computer,
driven by stepper motors and capable of precise movements,

Zeaker2 was the experimental prototype for Zero2. It was made in 1984 to my concept sketches by Jamie Campbell, a designer, called in by the others in our company, IGR, because they thought we were not capable. Although how an artist who knew nothing about hobby or educational robots was going to put us right was beyond me. Jamie made a solid working chassis and carved a former and vacuum formed a shell. To me the first shell in white made Zeaker2 look like something that belonged as part of a fridge. Fortunately he also made a clear shell. For development sketches etc see Zero2 development.

The Electronics were made by Basil Butcher again based on my ideas.

Zeaker2 has a two tone horn, indicator LEDs, a pen holder that can be raised and lowered by a stepper motor and of course two more stepper motors to drive two wheels, stability being provided by a toe under the front. It is powered and controlled through a byte wide umbilical.

Once Zeaker2 was made I started on the design and engineering drawings for Zero2.

In 1985, since Zero2 software was not ready, Robin Bradbeer, another member of IGR, wanted to take Zeaker2 to the USA to show it to Commodore and others so I wrote a suit of Forth words for a Jupiter Ace and with a Camel I/O interface, for a ZX-81, Zeaker2 could be put through its paces.

After Robin came back from the USA Zeaker2 ended up in a plastic bag on a shelf and remained like that until 2014 when I decided to see if it still worked. One ULN2003 was dead and once replaced I could then drive Zeaker2 from test programs on a Basic Stamp-2 (BS2). I took the oportunity to replace the original 16-pin DIL socket for the umbilical with a 2x8-IDC pin header and put some LEDs on the the data pins so I could see what was happening during testing.

I wanted to run Zero2 from my Zero2 control program that I wrote for the QL back in 1986 however floppy disks and microdrive cassettes for original QL computers have not survived too well the passing of time and so I tried various QL emulators for a PC. Only QPC-2 had an emulated serial port which connected to the original PC serial ports and also to USB/serial ports. However the PC operating system got in the way and operation of Zero2, which depended on a precisely timed byte stream through the serial port, was anything but smooth.

I was ill for the first four months of 2017 and couldn't walk much. Once I was a little better I decided to get Zeaker2 and Zero2 running from the PC by changing my QL program to send out ASCII commands instead of the byte stream and using an Arduino Uno to decode the ASCII commands and send out the required byte stream. I modified a program I had written for Bambino and built simple Arduino shields to take the umbilicals. Also I added a Pen-cam stop to allow automatic initialisation of the pen position to up.

The Arduino programs, controlled fom a serial terminal, allow sixteen 32 byte command strings to be stored and replayed as well as allowing control by converting the ASCII commands from the PC.

The umbilical to Zeaker2 provides 5v and 12v power and a 3 bit address plus 4 bit data bus with a write_ strobe.

    address 0 is the right stepper motor
    address 1 is the left stepper motor
    address 2 is the pen stepper motor
    address 3 is the horn and LEDs
    addresses 4 - 7 are for expansion

Each address can return 4 bits of sensor data when write_ is high.

I intend to make a daughter board with sensor interfaces and also an SP0256 speech chip (I have a lot of them). I have an almost completed SP0256 board, from 1985, for Zero2 as well.

The teachers strike and the collapse of IGR in the 80s sort of interupted things.