been quiet, working on a plan

Im going to get a 3D printer.  98% sure a Prusa Mark3 kit. I've been working on learning FreeCAD and Blender, and planning this. more to come soon.

and please feel free to leave comments if you have any thoughts or suggestions here.... 

thanks!

excel shortcuts. good article....

here is a nice link to an article on shortcuts in excel

 https://interestingengineering.com/top-40-best-excel-shortcuts-need-know

another good article on bad working drawings

def worth a read.

https://hackaday.com/2017/12/14/truly-terrible-dimensioned-drawings/

this looks like an interesting addition to the raspi Zero

its a kind of multi purpose extension board, check it out.

https://blog.hackster.io/pi-zero-docking-hub-adds-a-plethora-of-connection-options-8fd73e3599a9

My current project, a circuit that can remotely reboot a Rasp Pi.

right now I am working on a reboot circuit for my collecton of Pis.
Here is the basic circuit.

The Pi PCB board ( both the Zero and the larger rasp Pi 2 and 3 versions) feature a connection point where you can add a 2 pin header and create a remote reboot switch. on the rasp pi 2 and three you can see it here:

im building a little board with 8 transistor switches so i can reboot up to 8 Pi's remotely, from a master controller ( here a Raspi Zero)

ill post pics of the board and circuit shortly, and the results of the project.


update 1: i the reset button seems to work with the Zero, but for some reason the LED isnt lighting. still working on it...
Next im going to set up a rasp pi 2b with a header on the run/ground connection and then test the reset with that.

it looks like the prototype will have 5 channels. hopefully 4 of them will work....

So here it is, my home electronics lab...

so here it is. my home lab. we have all the basic tools and a basic start of about 10,000 parts, diodes, resistors, caps, transistors, etc

im ready to do some serious designing.

this is a pretty decent lab for a home experimenter.

the first major project is a couple of lab power supplies.

then a function generator.

and then a freq counter.

then we will see.....

Current Home Lab Parts list, .pdf and .ods files

this is a pretty through list of parts for a serious home hobbyist  or even the beginnings of a small professional lab.

the files are available in both .pdf and .ods format.


please feel free to use these as you like, also if you have any good suggestions or fill in any data please send me a copy so i can update my copy.


.pdf list

.ods list (spreadsheet, open office format)

this is just basic stuff i want to have on hand so i can do basic circuit prototyping etc at home. then i can order the boards and buy the best parts price and function wise.

this is total overkill probably for a beginner. 

seeking items for a electronics and mechatronics lab.

The title of this post says it all.

I am always seeking things i can use in a lab with students for building and working on electronics or mechatronics. some of the things ( but not all) that im looking for are:


oscilloscopes
signal generators
function generators
frequency analyzers
electronics parts, preferably unused
functioning computer power supplies, mother boards etc
tubes
old lab gear
soldering irons
books magazines etc

build your own cores program them into an FPGA

this is really cool if you have some advanced digital design skills:

https://opencores.org/

i was a designer at intel, its still an interest of mine.

ill be checking this site out over the weekend and reporting back but it would be very cool to build your own custom system on a chip. programming an FPGA with it wold be doable, the big problem would be cutting silicon.,,

various stuff on radio circuits

https://www.allaboutcircuits.com/textbook/semiconductors/chpt-9/radio-circuits/


http://www.instructables.com/id/Three-Transistor-Short-Wave-Radio/


http://www.ke3ij.com/am-univ.htm


https://makezine.com/2007/09/17/how-to-build-a-crystal-sh/


https://hackaday.io/event/27914-fundamentals-of-rf-hack-chat/log/70019-fundamentals-of-rf-hackchat-transcript




some stuff to get people started on RF signals

introduction to homebrew CPUS ( possibly using a FPGA)

http://www.homebrewcpu.com/

http://www.mycpu.eu/

two good sites on CPU design, always an interest of mine. having designed NPUs professionally.

capacitors and inductors.... introductory articles.

here are several useful articles on capacitors inductors and how RC and LR circuits work.

the key is that these devices store energy for later use. capacitors store energy in electric fields and inductors store energy in magnetic fields.  they are short term storage devices unlike batteries which are long term devices.


you need to understand how these devices work to build filters.....


https://www.allaboutcircuits.com/textbook/direct-current/chpt-16/voltage-current-calculations/


http://www.electronics-tutorials.ws/capacitor/cap_8.html


http://www.electronics-tutorials.ws/rc/rc_1.html


https://www.electronicspoint.com/threads/smoothing-capacitor-vripple.271842/

some useful sites on BJT emitter and emitter follower circuit design

follow the links, this should teach you how to build a functional emitter amplifier circuit, the most basic transistor circuit there is that is in common use.

http://www.experimentalistsanonymous.com/ve3wwg/doku.php?id=design_transistor_stage


http://www.experimentalistsanonymous.com/ve3wwg/doku.php?id=ss_circuit_engineering


http://www.radio-electronics.com/info/circuits/transistor/common-emitter-amplifier-design.php


and some stuff on emitter follower design:

http://www.experimentalistsanonymous.com/ve3wwg/doku.php?id=design_emitter_follower


http://www.experimentalistsanonymous.com/ve3wwg/doku.php?id=design_emitter_follower

common base design:

http://en.transistoramp.de/common-base-circuit/

various sites for experimenters, makers, hackers etc....

https://www.element14.com/community/welcome

this is a great place to meet other experimenters, hackers, makers, etc on the net, and a great source of inspiration for projects.

there are some others i visit regularly and post in occasionally.

here are some of them. all of them will give you great ideas for projects and are a great place to learn, document, and be inspired by....


https://makershare.com/

https://hackaday.io/myFeed

https://www.hackster.io/

https://github.com/johnfire

https://stackoverflow.com/

possible board fab

https://www.elecrow.com/

i havent used these people yet but am planning on trying them out for my next project.

once again experiences with this firm, thoughts suggestions etc would be welcome.

good shop for raspi and arduino projects

a lot of what i use in my projects comes from this store at the  link, Sertronics. 

i am always looking for suppliers of interesting stuff i can use for projects and experiments, both mechanical and electronic. if anyone knows any good suppliers feel free to share.

great course on machine learning

here is a great course on machine learning at Coursera. i did about half of it before work pushed everything else off the table. if you are interested in this area this is a great introduction. you'll need calculus and some exp with differential equations probably. have fun.


https://www.coursera.org/learn/machine-learning/home/welcome

Grendel One: background (my hobby/research project)

this is copied and pasted from a post at my element 14 page, enjoy.


I started this project about 2 years ago, after visiting a Maker Faire in Hannover Germany. I saw the NAO robot there, and after doing some research and thinking, realized I could try building a home brew version using a Raspberry Pi. At the time I was working as a full time language teacher here in Germany and wanted a computer test bed to work on language acquisition by computers. After some research and thinking I decided on attempting to build a general purpose robot with  a cluster of raspberry pi computers to process all the various tasks. The first version I attempted was based on the MPICH and MPJ interfaces which were not useful for my ideas. it consisted of a head with two axes of movement, and some basic experiments with the camera system and a skeleton operating program.  I was also working a research project for the university of Leicester at the time and decided to rework the robot, first by adding a body frame, and second by building my own message passing interface and running asynchronous programs on multiple pis that could adapt to what ever task was required. I used a 1950s Meccano set to build the head and the body; I got it on ebay.uk for about 140 Euros. Meccano is the original English version of the erector set that was popular in America back in the 50s and 60s. Meccano sets are ideally suited as a basis for a beginner home brew robotics project. There are lots of after market dealers that sell all the parts you need for building anything you need, and for about 150 Euros you can buy a big starter set that should def allow you to build something useful and play around with the parts. Since all the parts are drilled, it makes it easy to devise mounting systems for circuit boards, and other devices, and you can build a rigid, relatively light weight structure of your own design for a reasonable price.
I started by building a head, with two axes of movement, allowing the cameras to swivel up and down and left and right. I didn’t really use any formal plans, just some back of the napkin sketches: I knew I needed  framework to hang the cameras and microphones on that swiveled. Eventually I hope to expand to having arms and a system of movement for basic mobility, but some kind of device to carry cameras, distance sensors, microphones and speakers is essential in any such project.  It took about 3 days to come up with a suitable design that could carry one or two raspberry pis, two servos and the cameras. Later I decided to add an Arduino to control the servos and simply send short commands from one of the  pi’s to the Arduino. I started developing the software, the old version of which you can find at my github site, based on a test cluster of 3 raspberry pis.


In the next part ill talk about how developing the software for the first version led to the new version.

here is a link to a white paper i wrote on the project:

https://www.element14.com/community/servlet/JiveServlet/downloadBody/87820-102-1-369087/uploadFile.txt.zip

good blog article on using wifi on a raspberry pi zero

follow the link

https://www.piborg.org/blog/pi-zero-wifi-bluetooth

how to use GPIO pins on a raspberry pi in java.

how to access the GPIO pins on a raspberry pi computer in the java development environment.


http://pi4j.com/install.html

how to program a microcontroller using an arduino board.....

here is a good article on the difference between a real micro controller and an arduino development board, and how you can use the development board to program microcontrollers and build circuits around them...


http://www.instructables.com/id/The-RRRRRRRRRRBA-or-What-They-Dont-Teach-You-in-/

a good thread on how to take pictures with a raspberry pi camera

https://raspberrypi.stackexchange.com/questions/22040/take-images-in-a-short-time-using-the-raspberry-pi-camera-module

here is a good thread on how you make pictures with a rasp pi camera.

artificial muscles... maybe for a robot....

https://interestingengineering.com/these-artificial-muscles-lift-over-1000-times-their-own-weight

an idea that might be useful for  someone building a robot.

Sensor Kit X40 einführung

Nutz-voll Sensoren


http://sensorkit.joy-it.net/index.php?title=Hauptseite

great site for meccano replacement parts

https://www.meccanospares.com/

one place to get parts if you need specific stuff.

Wie man geht mit GNU Octave um.....

her gibt es ein link zur Einführung zum Octave, auf deutsch.

eine nutz-volle  Werkzeug für technischen Studenten.


http://math.jacobs-university.de/oliver/teaching/tuebingen/octave/octave/octave.html

useful digital simulator, on line.

i havent played with this much yet , but it looks like it could be a good learning tool for students.
if you need some kind of digital similator try this one. im not sure how big a circuit it can handle but has half and full adders, should be able to build the basics of a processor..

https://simulator.io/

very cool site on philips mechanical and electrical engineering kits

http://www.hansotten.com/electronic-kits/ee-series/ee8-ee20-a20/

worth a look, there are lots of useful things here for the experimenter.