2. Scrappy The Robot (2011)
Around September 2011 a young niece discovered I like toy robots (see bottom) and sent me her copy of a book by Carolyn Bear called 'Scrapman' (Oxford University Press, ISBN 9780199179985), which told the tale of a robot built from scrap in just a couple of weeks, who came to life in a thunderstorm before he was finished and had odd little idiosyncrasies as a result. One of these oddities was saying
od ear' when he didn't understand things, and 'volleygood' when he was happy.
As a way of thanking my little friend for her kind gesture, I decided to build her and her brother, their very own Scrapman.
To keep within the bounds of the book, I designed and built 'Scrappy' within the same period of about two weeks, working flat out on him with every spare minute, out of all the junk I could find in my various boxes, together with some bits and bobs from the dumpster at work.
Overall Scrappy stands about five feet tall with flexible arms and legs.
His head is made from a cardboard box and his entire body is sprayed with a nice metallic blue Hycote Rover Astral Blue Double Acrylic paint, similar to the colour in the photo on the front of the book.
Scrappy could not be who he is without speech and remembering long ago when I had played with the now obsolete SC-01 phoneme speech synthesis chip, I bought a modern equivalent SpeakJet chip alternative with input signals to select up to 9 sounds or phrases.
Inside his head I placed an old PC speaker / amplifier donated from my work IT department. His eyes are perforated metal discs taken long ago from Jaz removable hard drives (that had a bad habit of failing), and in the centre, bright yellow LEDs that flash when he speaks, driven by a TDA2822 headphone audio amplifier chip.
His nose is a thin strip of metal from my junk box, its original purpose long forgotten. His mouth is one of two large rubber grommets that once held the headlamp bracket to the forks on a Suzuki GS750 motorcycle. His ears are the gauze from two carburettor bellmouth venturi inlet velocity stacks, and on the top of his head are two automotive spark plugs with a coil of 10 gauge red insulated magnet wire between them for his hair.
His neck is the toner feed tube from a photocopier.
Left: his main body was an old purple rectangular household bucket (the original colour can be seen where some of the new paint has peeled away).
His arms are 1" diameter flexible hose, each end pushed into 0.5" diameter steel tube from an old wardrobe, that runs through the bucket. On the outside, inverted plant pot saucers cover the joins.
At the base I mounted a solid block of wood to mate with the top of his metal stand, which is the
upturned column from an old coffee table thrown out at work, covered by a 4" diameter cardboard packing tube.
His bottom is secured to this block using another length of 0.5" diameter steel pipe, the ends covered with discarded wine bottle screw tops.
His tummy is a recessed fluorescent ceiling light on which I mounted three coloured switches.
At the back of the light I added a 4" x 4" piece of square pad board on which I mounted the electronics
and connectors to the various switches around his tummy.
His chest is a junk circuit board on which I mounted a discarded pcb with a row of switches,
and a 9-way D connector for a PC RS-232C [D9]
serial port to program him to speak. I also added a Light Dependent Resistor (LDR) near the centre.
At the bottom is the heavy power supply out of a Sinclair Spectrum computer and at the top, a dc-dc converter insulated inside a small plastic chilli jar to power the loudspeaker in his head.
His bottom is a novelty Halloween orange pumpkin shaped bucket. The hose that forms the backbone of his arms and legs is covered by kitchen cling film cardboard tubes, with dismembered rubber fingers from household gloves stretched between the joins, on which more Jaz disc drive rings are mounted, spaced by thin slices of plastic pipe lagging.
His feet are ice cream tubs, secured inside by a small block of wood within which is another short length of 0.5" diameter steel tubing, the other end pressed into the 1" diameter leg hose.
His hands are plastic Energizer lithium AA battery holders and his fingers are tampon applicators. The battery holders actually have hinged tops providing more freedom of movement but I decided to keep them shut for added strength.
He is held together by a large number of nuts and bolts and a generous supply of melted glue sticks.
To the right is the pinout and summary from the manual for the SpeakJet voice and sound synthesiser chip, and below, the manual itself.
I found I needed to add a preamp circuit between the output of the SpeakJet chip and the input to the TDA2822 power amplifier and I built a prototype of it on a solderless breadboard before adding it to the circuit board.
I also set up the threshold and hysteresis limits on the light detection circuit - the round LDR can be seen screwed to a connector block at the top left of the circuit board.
To the left, the complete board located behind the light fitting in Scrappy's tummy.
I used a Maxim MAX232 chip to convert the PC serial port RS232C interface to the TTL levels required by the SpeakJet chip.
The serial port is now a distant memory on PCs, but a USB port can be used instead by converting it to TTL levels with a cheap eBay China converter module like the one below, priced at less than $1:
Below, the main circuit before the preamp was added:
The next step was to program the speech synthesis chip with phrases and sounds to respond to the light detector and the 6 buttons dotted around Scrappy's chest.
To complete the set-up, I downloaded
Magnevation's free and very useful Phrase-A-Lator program to control and program the SpeakJet chip using the PC serial port, available here:
http://magnevation.com/software.htm
The program controls are split into several sections:
Scrappy says 9 phrases:
When power is applied, he says:
Hello, I am Scrappy
Depending on which button is pressed, he says:
Od ear, Od ear
Vollygood
Hello Jimmy
Hello Amey
Chicken, fight like a robot!
I will be your friend
I am your robot
When a light is shone on his chest LDR he emits an alarm Whoop Whoop noise (to scare off burglars).
Scrappy also has an added feature I didn't plan. Like the original robot, he was deliberately built very quickly with the minimum of testing. Not long after he was installed it became apparent he needed a noise filter built into his power supply, because from time to time he randomly spurts out nonsensical noises. Ironically this gives Scrappy a personality similar to the original Scrapman in the book and I have no intention of taking it away from him. He is one of the family now.
502v01 P1150116 Scrappy says - I am your robot.MP4 - 917kB
502v02 P1150117 Scrappy says - od ear.MP4 - 366kB
Scrappy's eyes light up when he speaks:
Scrappy talking
Scrappy talking
Scrappy says - I am your robot
Scrappy says - od ear
The codes were all programmed into the speech chip's non-volatile memory using the free software, which allows instant playback although it is a little fiddly to use. In addition to phonetic speech, many musical tones are included, and the software has a selection of pre-programmed sounds, words and sentences that can be selected simply by entering them. 'Chicken, fight like a robot!' is one of these.
The codes for the phrases above are given below. The EVENT numbers identify the E0 - E7 inputs on the SpeakJet chip:
resethelloiamscrappy=\PITCH \165 \BEND \9 \NTE3 \HE \EH \LE \LE \OW \OWWW \DELAY \25 \OHIH \IH \AY \AY \MM \SE \CH \AXRR \AX \PE \PE \EYIY
EVENT7
alarmwhoopx5=\PITCH \165 \BEND \9 \NTE3 alarm, \A7 \A7 \A7 \A7 \A7 \RESET
EVENT6
odear=\PITCH \88 \BEND \5 \NTE3 \OHIH , \DE \IYEH,,\OHIH , \DE \IYEH \RESET
EVENT5
vollygood=\PITCH \165 \BEND \9 \NTE3 \VV \OH \OH \LE \IY , good \RESET
EVENT4
helloJimmy=\PITCH \165 \BEND \9 \NTE3 hello , \CH \IY \MM \IY \IY \RESET
EVENT3
helloamey=\PITCH \165 \BEND \9 \NTE3 hello , \AY \MM \IY \IY \RESET
EVENT2
fxberzerkchickenfightlikearobot=\PITCH \188 \BEND \9 \NTE3 chicken,, fight like a robot \RESET
EVENT1
\PITCH \165 \BEND \9 \NTE3 I , will, \BE \IY, your, friend \RESET
EVENT0
\PITCH \165 \BEND \9 \NTE3 I am your robot \RESET
Here he is in the lab having his speech chip programmed:
Above, everything wired up, ready for final assembly.
Left,a fresh lick of paint and Scrappy is finished!
Did I say I like robots?
One of my all-time favourite movies is the 1956 classic Forbidden Planet:
http://en.wikipedia.org/wiki/Forbidden_Planet
http://en.wikipedia.org/wiki/Robby_the_Robot
I loved Robby the robot, despite his awkward gait for such an 'advanced' machine. Long before I built Scrappy, I thought about building my own automated walking version of Robby, but there are so many curved sides to his body it would be difficult to do this without access to a plastic moulding facility. The original Robby was made out of fibreglass and I already had experience of that from building my futuristic GS920 motorcycle, but after that colossal effort I was happy never to work with fibreglass again. I discovered you could actually buy a full size model with a few automated features, but it couldn't walk which seemed a bit of a cop-out for something costing $10,000 in those days, and a whopping $32,000 in 2017: http://www.hammacher.com/product/10921
I also discovered you could buy 24" tall models of him sold as toys and I thought I'd buy one and mechanise it. When it arrived I found the giant hollow model was weighted down with plaster which would be very difficult to remove without damaging it. They were also surprisingly expensive and I realised
people were buying them for their collections, and I found there were many, many versions of Robby.
It was about this time I abandoned the idea of building my own Robby and instead started my own Robby Robot collection. Later I added a few others, including the famous Lost in Space B-9 robot:
Still on the subject of robots, here is the really impressive German Compressorhead robot band:
http://en.wikipedia.org/wiki/Compressorhead
The Youtube link I originally provided no longer works, but if you Google 'Youtube Compressorhead' you should find several of their excellent music videos there.
Equally impressive is this Japanese robot violin player: