Design: E13 

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This page is a copy of my old website at DDS which I used from 1999 until 2004 to document projects and ideas. Most of the files linked are still in place. The original can still be found at http://www.dertien.dds.nl

Symet

This is a typical solar-engine 'robot'. It is one of the most simple versions of solar-robots, designed on basis of the 'BEAM'-philosophy. Founder of this philosophy (and with that the creator of an enormeous bunch of ever-surviving robots) is Mark Tilden. The 'BEAM' philosophy comprehends the use of the following 4 notions in building robots: Biology, Electronics, Aesthetics and Mechanics (or just beautiful bio-inspired mechatronic devices)

(12-1999)

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Solarbug

This 'bug' makes use of a simple Flash-LED type "solarengine". With only a very small capacitor and a solarpanel from a calculator, its antennae start already to move when there is very little light present. The antennae are made of VU-meters from a discarded cassette player.

(12-1999)

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Solarroller

This also solar-engine 'robot'. The mechanics of this robot consist of a paperclip and some parts of a discarded walkman. For a summercamp I've organised a workshop where participants could build these solar-rollers. A (dutch) manual can be found below.

(12-1999)

<manual(dutch)[252kb]> <pcb.pdf[11k]><image[18kb]>

Suneater

This is my version of a great solarbot-design by Steven Bolt. It is one of my first home-made SMD projects. Two motors from discarded CD-rom players were used, a 4700uF cap, the pcb with two light-sensors and two bumper-switches. At this picture I use only one solar-cell. Later on I added a larger solarpanel in order to increase the available voltage.

(11-2000)

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Javastorms Challenge

Together with Bert van den Berg and Jan Broenink I participated in the JavaStorms Challenge, organised by the a software developement company called "Chess IT".<read more...>

(07-2002)

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LEGO bug

A simple lego bug (with old-fashioned 4,5 V motors). The reason I put it here is probably because I like photographing all kind of stuff. At the moment I'm experimenting with reflective Quadrature-encoders in order to do some odometry. More data will follow

(02-2003)

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IR proximity sensor

This is a simple switching-type IR proximity sensor, compatible with the RT AVR-board. There is a profound difference between proximity sensors and distance sensors. Distance sensors, like the LEGO sensor described elsewhere, give a variable value depending on the distance of an object placed in front of it. Switching type sensors such as this one give a signal at a preset distance. It makes use of the IS471 modulated IR sensor. PCB and schematic can be found below.

(09-2003)

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AVRstamp

This is the first result in an attempt to build a 'basic stamp' with avr, using the attobasic interpreter by Dick Cappels. At first this PCB was designed for using an MEGA163 on ordinary breadboard-systems, but instead of only a simple TQFP-dil adapter I decided to place a small power circuit, EEprom socket and the oscillator circuit on board as well. The first project this controller was used in was the balancing LEGO robot.

(08-2001)

<image[72kb]><website attobasic>

MIDI keyboard

This is a picture of the MIDI keyboard in case. The electronics need only two penlites to run on, and since the only load to drive is a MIDI LED (the input optocoupler of the connected device) it consumes very little power. (considerably less than the original 1,5 Amp the SIEL DK70 took)

(08-2001)

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Midi Keyboard

I've used an old SIEL DK70 synth as midi-keyboard for my pc. It drew 1,5 amp at 12V, which made it less apt for portable usage. With an AVR AT90S1200 and a few extra components I've tried to build a working midi-keyboard using the keys of the DK77. The software was written in assembly and consist mainly of a 31250 Bd-software-UART.

(03-2003)

<image[21kb]> <source.asm[13kb]> <pcb.pdf[25kb]>

MIDI-splitter

This device was developed for adding a channel-splitpoint to midi-keyboards. The note-on and note-off commandos that come in at channel 1 are splitted. The notes above a during startup selected key are send to channel 2. This module was first designed with a AT89S2051. Due to easyer-programming it was later replaced by an AT90S2313. The software was written by Thiemo van Engelen.

(08-2001)

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Virtual Presence

Goal of this project is to develop a sort of "virtual presence" robot. Remote controlled via an interned-connected PC, a user should be able to drive it around the house (and watch the cat). The first version contains only the camera and pan-tilt head. This next version contains the video-transmitter as well, along with a new camera-housing and an extra stage for mounting the RTAVR board and battery-pack. Although the transmitter normally requires a 12 Volt 500mA adaptor, it works fine with a NiCd 9,6V pack.

(09-2003)

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Domestic Robot

This is one of the most recent robotplatforms I've build. It contains six wheels from the RealRobots magazine-kit. Furthermore I've build a pan-tilt camera head in 'Lynxmotion style'. Ad this moment a security camera is added (build-in in a discarded mosquito-scarer). This camera produces black-and-white images. A wireless (2,4Ghz) transmitter will be added later on. The platform will be controlled using the RT-AVR-board. Control signals will be transmitted from a host-PC to the robot by the 433Mhz transmitter that comes with the 2,4Ghz wireless-set. Below are links to more pictures and the pan-tilt head parts.

(03-2003)

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Starlight simulator

A simple program for generating a random PWM controlled slow 'flash' at eight different rates. It was used for lighting the collar of a tuxedo worn at a dressed party.

(03-2003)

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RT-AVR-board

I've been developing this board for the Createch design com petitions at Twente University. It contains an Atmel AVR Risc Microcontroller (type AT90S8535). The design of the hardware is inspired by the MIT Handyboard . The board can control up to eight servo's, has eight analog inputs, I2C output, an alphanumeric LCD display and 2 PWM motor outputs. A standard RS232 link is available and the board can be programmed using for example the SPI programming adapter for the STK200 board by Kanda Systems.

(09-2002)

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Programming tool

Programming of AVR microcontrollers can easily be done by using a LPT programming adapter. The Kanda systems STK boards use similar adapters as well. (In fact, I've build my programming adapter compatible with the STK-200 adapter). This PCB design of the programmer was made for the RT-AVR-board. I've build them as well on breadboard (see picture below).

(06-2002)

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Miniature Robot platform

A robot platform developed for the Control Engineering department of Twente University. The goal of this research project was to develop a new target-system for ongoing research towards communicating processes whithin hardware. Inspired by the MIT Ants it became a small and cheap robot-platform. Below the project report and two aditional images can be found of the communication module and one more of two robots.

(07-2002)

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Mini-robot

This robot was the ancestor of the Humke Robot-platform. This robot contains a 74HC244 used as H-bridge, a microcontroller and a small battery. The motors are the same as used for the Humke Platform

(03-2003)

LegWay

Looking for a new idea for an assignment for highschool students (I'm developing educational "workshops", offered by Twente University for highschool students) I found Steve Hassenplug's "LEGWAY" robot. This LEGO Mindstorms robot is able to balance on two wheels, drive around, spin, and follow a black line.

(03-2003)

<LegWay site>

Segway

Inspiration for these balancing robots came from the "segway", a revolutionary balancing personal transporter. This platform can carry but one person, maintaining balance using an advanced set of gyroscopic sensors. detailed information can be found on the segway company website.

(04-2003)

<segway site>

GP2D120 sensor

Steve used sensors from Hitechnic.. Compared with the standard LEGO sensors these sensors gave a higher resolution for distance measurement. Due to capacity problems Hitechnic ceased production a couple of months ago, so for our assignment we had to find a substitute. First I've tried to get a Sharp GP2D120 psd sensor to work with the RCX. The design and schematics below were used during LEGO robot contests (April 2004) at the faculty of Computer Science at Twente University too. Students came up with a correction on the schematics (missing ground link) so below now an updated version of the schematics can be found. This schematics below enables you to adjust amplification and DC treshold. It uses however one RCX output to powerup the sensor. This schematic used to use only one sensorinput, but now they changed it to a two-line circuit too, because of an increase in processing speed.(Their original design used to use a capacitor, charged by the sensor-input port for powering the GP2D120 sensor)

(05-2004)

<schematic[12k]> <image[17kb]> <Website other sensordesign>

Sensor tests

The Sharp sensor was tested using BricxCC, an extensive NQC development environment. Using its Datalogging capabilities the resolution and accuracy of the Sharp sensor were tested. Steve used BrickOS (formerly LEGOs) as control software. Timers within BrickOS can be used up to 1kHz, which make the fast loop necessary for balancing possible. Timers in NQC (Standard LEGO RCX firmware) can run as fast as 100Hz. Closer examining the results of the Sharp sensor data (and closer inspection of the datasheet) revealed a realy annoying fact: The refresh rate of the PSD sensor is only 25Hz, taking 40ms for each measurement. As could be expected, the robot could not be balanced with this sensor... :(. Below are pictures of the BrickCC measurements, captured at various speeds of sensor-distance change, at a sample-rate of 100Hz.

(04-2003)

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New sensor design

When the Sharp sensor system would'nt work, a new sensor was developed. This sensor uses an atmel avr microcontroller which drives an infrared LED, measures the returning signal on a photodiode and generates an analogue voltage (pwm) which can be interpreted by the RCX. (Data can be read out in a way similar to the standard LEGO light-sensor). The sensor measures difference between ambient light and the reflected IR light. furthermore the ouput can be calibrated in the sensor's internal software. This solution (using a microcontroller instead of simple discrete and linear components) seams a bit "overkill" but we were desperate to get this robot working, and the sensor we now have is flexible easy to work with (and cheaper compared with a rather expensive Sharp GP2D120 sensor)

(05-2003)

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Finally: A balancing robot

With rubber bands and cellotape a breadboard with AVR, other components and a battery were attached to the LEGO model. The short movie-clip shows that the controller algorithem is still in need of some fine-adjustment...

(05-2003)

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LEGO compatible IR distance sensor

This is the final design of the RCX compatible distance sensor necessary for balancing a LEGO robot. The board is two lego units wide and 9 units long, contains power regulator, Atmel Microcontroller an opamp, fotodiode and IR-LED. This design requires the power fed through an extra wire, instead of using the same, as in the original LEGO light sensor design. Perhaps a future version will use only one wire as well.

(11-2003)

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Final Assignment

The final model looks a lot more like Hassenplug's original version than our testversion (and it requires far less lego parts to build) and works fine. During the field-trial of our assignment 5 high school students as guinea pigs managed to get their robots finaly upright. More elaborate skills like line-following while balancing, as Steve displayed on his website, are yet to come...

(12-2003)

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links

Serial Interface

A simple and straightforward serial interface for the PC to control a couple of motors

(09-2002)

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GP2D120 interface for RCX

This simple interface circuit enables you to use a sharp GP2D120 distance-sensor with the LEGO Mindstorms RCX-brick.

(09-2002)

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HorseshoeCrab

As described in an Article in UT news, I build a horseshoe-crab shaped RobotWars-like robot as a welding-course project. The idea to use a horseshoe-crab as example was inspired by a robot called 'dizzy', by Steven Bolt. Power supply and steering are not implemented yet (I forgot the Ackermann-principle, so the robots turning behaviour is horribly bad). However, the main motor and gear-train work fine.

(07-2002)

<workshop provider> <image[156kb]>

Willie

Willie is the first mobile robot I've build. It came as a kit, described in articles of the dutch popular science magazineKIJK. The kit was designed by Steven Bolt. On his page you can download the schematics as well. With the kit also a recharge-unit came, which the robot could find by itself.

(03-1993)

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Fire detecting Intelligent Robotic Extinguisher (FIRE)

This beautiful acronym (the AAAAA (American Association Against Acronyme Abuse)won't agree) was given to this robot I've designed for the Dutch Young Scientist Contest of 1996. The theme of the contest was 'Water and Fire'. This robot was controlled by an Acorn BBC computer, used infrared-sensors to locate a fire and contained a small extinguisher.

(10-1996)

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basic platform

This threaded platform was used as a moving robot 'prey', while carrying an Infrared Beacon that the robot platform ARTY could track The platform consists of old 'amproh' aluminium bars, two motors, H-bridges and a gap in which a small 12V Sealed lead acid battery could fit. When this robot was used as demonstration-'prey', a RC receiver and two servo's with microswitches attachted to them were added, as can be seen on the pictures below.

(06-1999)

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ARTY

Arty was a second-year Bsc project at the CE groop of the Electrical Engineering department of Twente University. With four other students: Wietse Balkema, Gijs van Oort, Pepijn Boer and Thiemo van Engelen we developed the electronics for this robot platform in three months. The electronics consist of a 486-pc (PC104 standard), a control system for the wheels (PID, with quadrature encoders), control system for eight polaroid ultrasonic sensors, control system for a turning RC5-Ir receiver and a power system. Arty is powered by a 6V sealed lead acid battery.

(06-1999)

<image[34kb]> <project website>

The Idea

Wout Zweers, a local artist asked my assistance for an interesting large piece of art: a mobile robot which is going to make graphical art, based on music inputs. A 3 meter wide contraption consisting of discarded wheelchair parts and steel tubing is going to drive around, spraing and drawing on the surface, which can be a city-square or a theatre-floor or everything in between.

(03-2003)
<homepage Wout Zweers>

Redesigning some wheelchair controls

For me as electronic engineer not much more to do than hacking an old wheelchair control-panel. The signals of a dynamic analogue joystick have to be mimicked, just as the signals of a keypad. Because of time constraints we chose this "reverse engineering" approach instead of a "design from scratch" way.

(03-2003)
<homepage Wout Zweers>

Workshop

The first test of the beautiful developed and assembled PCB. The number of bugs was totaly murphy-compliant, not much more than to be expected, and, nice enough, mostly to be dealt with in software. After some testing (DAC signals mimicking the joystick would't work) the lot was taken home for some extensive programming

(09-2003)
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MEGA 8 controller

This small microcontrollerboard contains a MEGA 8, and is capable of controlling quite a number of RC-servo's. In fact, this board is a small piece of a PCB-design for the Music Robot, but was designed modular. As can be seen on the picture at the links below, it can be connected directly to a RS232 terminal interface adapter (max232 circuit) and a power circuit.

(08-2001)

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Desktop model with Fischer Technik

Between all the tinkering with the PCB and microcontroller software I build this illustrative fisher technik model of the robot, showing what a mess this robot project is going to create, at least at desktop scale.

(09-2003)
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Driving around

This pictures are taken during the first actual tests of the working electronics The bugs of the previous workshop day were fixed, and full control of the beast was taken by means of the laptop computer. Unnecessary to say, the machine had a mind of its own, resulting in smashing into tables and workbenches with me on top figuring out to which laptop-button I assigned the stop-function...

(10-2003)
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New Machine

After the last testings new electronics are being developed. MIDI is chosen as interface between the robot and computer. In the meanwhile Wout created this new robot construction which is now the denoted 3 meters wide. Below some pictures of the first crayon drawn figures are listed.

(11-2003)
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