The Geeky Nerdy Project Page

[IEnjoyPiss 189]

1 minute ago, Sexismygod said:

I thought about putting this in the Funny stuff thread but it's pretty geeky.  Quite possibly a "funny if you were there" moment.

This happened at a trade show many years ago when we got the 3D signaling controls backwards on a virtual reality system.  The 3D looked horrible until someone figured out the rather easy fix (can you spot it?).  Certainly better than stopping the presentation and re-configuring the system.

Genus way of handling it

[Kupar 12,315]

Quick update on the bat detector thing (as K spotted a bat in the garden the other day and I realised I had been v poor about actually building anything, so now want something quick).

And I am afraid I have wimped out somewhat and will be assembling a heterodyne detector from a kit (I know, I know). It's a long-established design and while I don't know the frequency response of the ultrasound sensor it uses, I figure that as it's successful in the UK market it must be able to cope with common UK bat species (the most common species - for PeeFans the rather wonderfully named pipistrelle - clicks at around 48kHz). 

Here are the circuit diagram and parts list for those interested.  

Incidentally, for the digital full-spectrum approach, this looks interesting (if you didn't want to design and build your own): https://www.openacousticdevices.info/audiomoth 

And should I get hooked on bats, and want to record and analyse the waveforms, I promise to build a digital detector / recorder of my own.

Edited March 27, 2022 by Kupar

[Maclir 932]

Geeky nerdy information about myself... my hobby is model railroads.  I have an extensive collection of HO scale trains, mainly US models, the Delaware, Lackawanna and Western, Erie, and Erie Lackawanna lines, from the North-East USA, plus some New York Central passenger trains.  I'll be at the clubhouse running some trains later today.  If anyone is interested, I can post pictures and all that...  but it's pretty geeky... 

[Kupar 12,315]

3 minutes ago, Maclir said:

Geeky nerdy information about myself... my hobby is model railroads.  I have an extensive collection of HO scale trains, mainly US models, the Delaware, Lackawanna and Western, Erie, and Erie Lackawanna lines, from the North-East USA, plus some New York Central passenger trains.  I'll be at the clubhouse running some trains later today.  If anyone is interested, I can post pictures and all that...  but it's pretty geeky... 

I'd be interested 🙂  Is everything digitally controlled these days, or is there still old-fashioned circuit-switching in the layouts?

[Maclir 932]

7 hours ago, Kupar said:

I'd be interested 🙂  Is everything digitally controlled these days, or is there still old-fashioned circuit-switching in the layouts?

Digitally controlled - each loco has a small circuit board with a processor chip called a 'decoder' - so each loco has a distinct address, and on your controller, you first 'acquire' a loco by it's address, and your commands (speed, direction, turn on lights, ring bell, blow horn, etc) are sent encoded on the track power to that loco address.   I've just come back from the club running one of my engines.

[Kupar 12,315]

Excellent - and the modelling of the cutting looks good - do you make things from scratch? Lichen for bushes and that sort of thing?

[Maclir 932]

13 minutes ago, Kupar said:

Excellent - and the modelling of the cutting looks good - do you make things from scratch? Lichen for bushes and that sort of thing?

That is at our club's layout - the First Coast Model Railroad Society, in Jacksonville, Florida.  We have a web page - http://fcmrs.club/

[Kupar 12,315]

Wow - that's a big layout! Really nice.

[gldenwetgoose 20,207]

Interesting chat on digital model railway control...   In my childhood days of my Dad and I building layouts it was always analogue  - although fairly advanced with a Regulator / Brake control, zone isolation and separate shunting controllers.  All his design.

But we both aspired to the Hornby Zero-One system...   able to digitally control 16 different locos on the same track.  The future in 1979!

https://dccwiki.com/Hornby_Zero_1

[likesToLick 9,715]

20 hours ago, Kupar said:

Here are the circuit diagram and parts list for those interested.

Looks like it is using a tunable beat frequency oscillator to add a signal to the amplified ultrasound,  thus producing a beat frequency that lands in the human audible spectrum.  Is that right?

[Kupar 12,315]

20 minutes ago, likesToLick said:

Looks like it is using a tunable beat frequency oscillator to add a signal to the amplified ultrasound,  thus producing a beat frequency that lands in the human audible spectrum.  Is that right?

Exactly so. A heterodyne circuit 😊

[Kupar 12,315]

Assembled (a nice, neat and tidy PCB layout - thanks Magenta Electronics), tested and, afaik, working (inasmuch as it picks up the ultrasonic component of test signals from the jangling of keys). A final report when the bats next make an appearance in the garden.

[Kupar 12,315]

OK - a quick report. It works. I saw a bat flitting around the garden last night and went out with the detector, scanning up and down the frequencies until I could her the clicks from the speaker. At pretty much exactly 30kHz, there it was - irregular 'wet slapping' sounds of the bat's echolocation signals. Coupled with the size of the bat I could see, and the flight path around our garden, I identified the bat as a Serotine bat https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/mammals/serotine-bat/  

I plugged a little audio recorder into the headphone socket of the detector, turned the gain down (the headphone output is a little loud for the recorder input) and later opened the recording in Audacity, reduced the circuit noise and looked at the waveform and spectrogram. 

This is only the first attempt, but I am pleased with it. Note that in the spectrogram below, the frequency scale is all wrong because Audacity is processing the audible detector output not the ultrasound signal. If anyone really wants to hear the recording, let me know.

[Sophie 22,991]

4 minutes ago, Kupar said:

OK - a quick report. It works. I saw a bat flitting around the garden last night and went out with the detector, scanning up and down the frequencies until I could her the clicks from the speaker. At pretty much exactly 30kHz, there it was - irregular 'wet slapping' sounds of the bat's echolocation signals. Coupled with the size of the bat I could see, and the flight path around our garden, I identified the bat as a Serotine bat https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/mammals/serotine-bat/  

I plugged a little audio recorder into the headphone socket of the detector, turned the gain down (the headphone output is a little loud for the recorder input) and later opened the recording in Audacity, reduced the circuit noise and looked at the waveform and spectrogram. 

This is only the first attempt, but I am pleased with it. Note that in the spectrogram below, the frequency scale is all wrong because Audacity is processing the audible detector output not the ultrasound signal. If anyone really wants to hear the recording, let me know.

Omg that is awesome! 

[Maclir 932]

On 3/27/2022 at 5:20 PM, gldenwetgoose said:

Interesting chat on digital model railway control...   In my childhood days of my Dad and I building layouts it was always analogue  - although fairly advanced with a Regulator / Brake control, zone isolation and separate shunting controllers.  All his design.

But we both aspired to the Hornby Zero-One system...   able to digitally control 16 different locos on the same track.  The future in 1979!

https://dccwiki.com/Hornby_Zero_1

with analog (old style DC), you drive the track.  With DCC, you drive the individual engines.

[pguy2981 929]

On 3/27/2022 at 3:42 PM, Maclir said:

That is at our club's layout - the First Coast Model Railroad Society, in Jacksonville, Florida.  We have a web page - http://fcmrs.club/

The child inside of me is screaming. You won't know it but I WILL be paying this place a visit at some point soon.

[Sophie 22,991]

I'm not sure how interesting you guys will find this (or if you will find it interesting at all) but I thought I would share anyway.

Recently I purcharsed a vinyl cutter, a Silhouette Portrait 3, and there are LOTS of free SVG files on the internet for me to download and cut out to my hearts content. SVGs are great because they are scalable without losing quality. However... the Silhouette software requires a paid version to open SVG files, but it does allow you to open a PNG. I could convert the files manually one by one but that is time consuming and rather boring, I could probably find some software to do it but where's the fun in that? So I made my own in Python, it does exactly what I want it to, no more, no less.

The script I wrote takes any SVG file in the directory, converts it to PNG and then saves it in a seperate directory, all with the click of a button. I can convert 100s of files in mere seconds, it would take me hours to do it manually. The code is below for anyone interested. Basic, but effective.

import cairosvg
import os 

def main():
	path = 'C:\\Users\\Sophie\\Pictures\\SVG'
	files = os.listdir(path)
	for file in files:
		if file.endswith('.svg'):
			filename, extension = os.path.splitext(file)
			cairosvg.svg2png(url=file, write_to=f'PNG//{filename}.png')

if __name__ == '__main__':
	main()

 

[Kupar 12,315]

6 minutes ago, Sophie said:

I'm not sure how interesting you guys will find this (or if you will find it interesting at all) but I thought I would share anyway.

Recently I purcharsed a vinyl cutter, a Silhouette Portrait 3, and there are LOTS of free SVG files on the internet for me to download and cut out to my hearts content. SVGs are great because they are scalable without losing quality. However... the Silhouette software requires a paid version to open SVG files, but it does allow you to open a PNG. I could convert the files manually one by one but that is time consuming and rather boring, I could probably find some software to do it but where's the fun in that? So I made my own in Python, it does exactly what I want it to, no more, no less.

The script I wrote takes any SVG file in the directory, converts it to PNG and then saves it in a seperate directory, all with the click of a button. I can convert 100s of files in mere seconds, it would take me hours to do it manually. The code is below for anyone interested. Basic, but effective.

import cairosvg
import os 

def main():
	path = 'C:\\Users\\Sophie\\Pictures\\SVG'
	files = os.listdir(path)
	for file in files:
		if file.endswith('.svg'):
			filename, extension = os.path.splitext(file)
			cairosvg.svg2png(url=file, write_to=f'PNG//{filename}.png')

if __name__ == '__main__':
	main()

 

🙂 That looks simple and elegant. And have you made some nice stickers and things? 

[Sophie 22,991]

1 minute ago, Kupar said:

🙂 That looks simple and elegant. And have you made some nice stickers and things? 

Not yet but I am planning to! I had a great idea for my water bottle the other day so that will be happening soon.

[Kupar 12,315]

3 minutes ago, Sophie said:

Not yet but I am planning to! I had a great idea for my water bottle the other day so that will be happening soon.

Excellent!

[gldenwetgoose 20,207]

Love it @Sophie  - You have the coolest geeky projects.   I may be grovelling enormously ahead of our European roadtrip next summer - just two caravans and a camper so not like a bulk order.

[gldenwetgoose 20,207]

Just for a bit of fun, since this thread has been dormant for a while.

What's the height of the table?  From floor to tabletop?    And in best school tradition, don't forget to show your working out...

[avatar 371]

2 hours ago, gldenwetgoose said:

Just for a bit of fun, since this thread has been dormant for a while.

What's the height of the table?  From floor to tabletop?    And in best school tradition, don't forget to show your working out...

Oh, you just gave me a nice reason to try out the built in stylus that came in my new phone, since I really don't feel like getting out of bed for a pen and paper.

Please excuse my handwriting, basically T means table, Tu means turtle and C means cat. 

Edited February 14, 2023 by avatar

[Kupar 12,315]

5 hours ago, avatar said:

Oh, you just gave me a nice reason to try out the built in stylus that came in my new phone, since I really don't feel like getting out of bed for a pen and paper.

Please excuse my handwriting, basically T means table, Tu means turtle and C means cat. 

VG. ✔️

[Kupar 12,315]

I was looking at this thread the other day too, and thinking that we hadn't posted much here recently ... clearly the winter (for us in the northern hemisphere) obviously hasn't been a particularly productive time when it comes to tinkering around with nerdy projects.

But here's a not-very-geeky/nerdy contribution, just because I love an Excel chart. This is for my attempt to do 2800 press-ups in February. I confess part of my motivation is to see the chart develop over the month lol. (The dip is a couple of days' rest after I gave blood 🙂.)