DIY software development and/or electronics?

Fixing and making things, what tools to get and what skills to learn, ...
CDR
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Joined: Sun Sep 06, 2020 9:45 pm
Location: Canada

Re: DIY software development and/or electronics?

Post by CDR »

On the DIY Programming side of things, I really enjoy writing scripts to automate tasks at work (majority of my experience) or at home (a little bit). I put together a python script that will smash together all the spreadsheets from my bank, pick out the transactions for the month I want, and put it in a new spreadsheet with the savings and spending rate calculated.

I've also taken to using scripts and the computer to schedule very simple recurring tasks. Like have my computer open a web browser to my bank website every Friday so I review my transactions (not logged in, for safety reasons :)).

Webscraping is a great area for DIY. Much easier to have a program that checks a website or forum every hour or 30 minutes for something than to do it yourself. Whether you're looking for a job, house, place to rent, free stuff, particular things (for example, a particular type of broken item), it's pretty easy to write a script for a particular website and let it go.

Just like sclass is always saying about the hardware side, it's really easy to find tutorials on youtube or else where on the web to get started with this stuff.

I use Python most of the time, automate the boring stuff is a great book that teaches you python and how to write scripts to automate things at the same time. You can read the book (legally) online for free: https://automatetheboringstuff.com/

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Sclass
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Re: DIY software development and/or electronics?

Post by Sclass »

That’s awesome that you do that with Python. I was wondering what the right tools were these days. It’s kind of funny how I forgot about all my labor saving tools when labor was gone.

About fifteen years ago I learned just enough Python to check my reports’ time sheets on our server to make sure they filled them out before Friday afternoon. If they didn’t they’d get an automated warning via email. Basically the same calls you use above. I did some scraping for Craigslist free listings for biofuel (waste restaurant grease) with Python at the time too since the alert apps didn’t exist yet. I always was first because I programmed it to text my dumb phone. The local hippies were pretty fast but not faster than my scrape every thirty seconds. I did another one that would email me reports of how many units my assemblers had made/tested daily and their rate of production by the hour. It was really good to know what times were best to walk the line and “motivate” the troops. They thought I was snooping their web traffic on the test stations but I was simply compiling their test reports. When I ran a little virtual vending machine I wrote one to subtly change the text on the site daily because it definitely kept me higher on the search rankings at Google to have daily updates to the homepage. My version of SEO was changing five characters...only Google noticed. That was really neat stuff. After retiring I haven’t done anything like that.

CDR
Posts: 57
Joined: Sun Sep 06, 2020 9:45 pm
Location: Canada

Re: DIY software development and/or electronics?

Post by CDR »

Kind of makes sense, it seems like the perfect time to forget about them :P.

Funny enough, it was almost that long ago that I learned Python. I learned it in high school. I've just gotten 'lucky' that Python has become so big.

Love the idea of using scripts to help manage your reports, not that I have anyone to manage, but something I will keep in mind! Also, that's the kind of SEO I can get behind!

I'm starting a new job in IT, so I'm getting antsy to see what kind of scripts I'll be able to cook up :).

SavingWithBabies
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Joined: Mon Aug 31, 2015 2:50 pm
Location: Midwest, USA

Re: DIY software development and/or electronics?

Post by SavingWithBabies »

@Sclass Just catching up. Yeah, I know it's not hard to setup a test fixture. I just want to wait until I need one. I'm sure I'll make some custom PCBs one day I just don't have a need yet so I'll wait until I get there. I guess I've got a subset of interests that I'm waiting on until I have more time/space/house/workshop. Like the lathe and the mill. Hopefully one day.

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Sclass
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Re: DIY software development and/or electronics?

Post by Sclass »

I picked up a new oscilloscope. A Rigol DS1054z. It was really cheap. $349 inlucing shipping on Amazon. 100Mhz, 1GS/s, 24M points memory depth. Amazing for the price. I sold some stuff to make room and lo and behold it was a free upgrade.

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Not sure what is going on here but it is a good scope for the money. It’s kind of a Toyota Corolla of scopes. Fast enough and incredibly useful. Unbelievably priced. Good for hobbyists wanting to go beyond the $16 bargain basement models I discussed earlier. About the size of a boom box instead of a carryon suitcase so it’s quite portable. I was going to buy the fancier model with the logic analyzer inputs but I thought about it and realized that parallel is dead. The world has gone serial except for some of the highest speed chip to chip communications interfaces. This thing has serial protocol analysis on its four analog channels so you can do “logic analysis” on i2c busses with a single wire. I’m becoming a old engineer chasing after tools for obsolete tech. I really wanted 16 logic analysis channels but seriously I haven’t needed to do anything like that as USB serial/JTAG debuggers have replaced old school logic analysis.

plantingtheseed
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Re: DIY software development and/or electronics?

Post by plantingtheseed »

Oh that's pretty!

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Sclass
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Re: DIY software development and/or electronics?

Post by Sclass »

Hi I just bought one of these cheap oscilloscopes for fun. It is a pretty cheap one so I thought I’d show it here. Advertised 200KHz bandwidth so it is kind of a toy but it is great for people starting out who just need to check a time varying signal on a hobby project. I notice these are popular among the DIY synthesizer crowd. A friend of mine directed me to it. He uses his to set up his homemade music synthesizer.

Good for learning. Low barrier of entry. Little risk. And best of all it works as advertised. It’s a big step up above a simple voltmeter if you want to look at signals. It has a single trigger mode which is great for trapping fault conditions.

Cost me about $27 shipped. I chose the non battery powered model and regretted it. Buy the battery powered model. I thought I could just solder in a battery and it would be the same but it turned out they didn’t populate the USB port charging circuit on my cheap variant. So I had to build my own out of a TP4056 board and it was a pain. Consumed a couple of hours and a $0.75 TP4056 board.

I used an old candy bar phone battery to power it. I kept those old dumb phones because they double as battery chargers even though they don’t work as phones anymore. My battery was still good and I charged and checked it out with the phone. Then I transplanted the battery to this baby oscilloscope. Works but I spent a couple of hours figuring out how to hack it in an solder up all the wiring. Definitely not worth the $3 savings for the non battery version. So just get the one with the battery. I opted for the one without a probe simply because I have piles of probes here. The probe option is cheap though. For a beginner I’d just get the whole package - scope, battery + probe which comes in at $35.

https://youtu.be/c7s6_YIaUJc

I 3D printed a case for it. A guy on Thingiverse posted a free case. It's nice. The unit ships as kind of a stack of pcbs and it is open on the sides. This box makes it feel more like a handheld instrument. Pretty good for a free download and a few pennies of filament.

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Sclass
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Re: DIY software development and/or electronics?

Post by Sclass »

I built a pulse welding attachment for my TIG welding machine. I bought a really cheap TIG machine that didn't have pulse welding control. Pulsing is basically turning your torch on and almost off to regulate the thermal energy going into your weld. The idea is the heat flux is very high at the weld but if you cut the power right after the weld pool becomes molten you stop heating before the heat flows away into the bulk of the part. It's kind of a race between how fast you can dump heat into a small point on a plate of steel and how fast it diffuses away into the plate.

There are some benefits like less heat diffusion into the overall body of the part. Heat only gets to the weld zone. Melting and freezing becomes very regular and localized. Also it makes a novice welder look like he has some skills that in reality take many years to develop. It's a cheat button for making consistent "stack of dimes" welds. Old school welders call it a cheat to just lay down a filler wire and pulse over it but I would like to try it out. I never mastered real torch dexterity and I probably never will. And I'm a sucker for cheat buttons.

Any how enough of that theory. My cheapo welder doesn't have pulsing. I didn't feel like paying the extra $100 on my $134 welder to get this feature. I figured if I wanted it I could build it. All I needed to build is a mechanical finger that would hit the arc switch on the torch at 1Hz with a 30% duty cycle. 300mS on, 700mS off. Over and over again like a metronome. This is easy to build using a 555, Arduino or a bare bones microcontroller setup. I have all three lying around in my junk boxes. But all of those require engineering - circuit design, five lines of code, a PCB layout.

The thought here was to do this project with off the shelf modules that are prebuilt. All that is required is hooking it up with wire. So there needs to be a connection to the welder and torch. Those are GN type connectors. A signal or pulse source - I bought a prebuilt one with with a programmable duty cycle and frequency. A relay to switch to put in series with the arc start switch. All this stuff is available prebuilt and cheap online. I wanted it to be battery powered so I used a battery salvaged from a disposable vape device I found on the ground. I used a little USB to lithium battery charger module for charging. A 3.7V to 5V boost module to bump the battery voltage up to something the pulse source and relay could handle (5v). The idea is to show that DIY electronics can be really approachable without intense hardware or software skill requirements.

That easy. Click click click order stuff on ebay and wait a few weeks for it to arrive from china. $6 for everything including shipping. So I repeat, yes you could build this...but the idea was to order a bunch of premade stuff and just wire it together. No design, no code, no PCB. It's painless DIY electronics.

And here it is. I call it my mechanical thumb. It is wired in series with my arc start button on my torch so when I press the start button it interrupts the connection every one second for 700mS or whatever duration I set. It uses the upslope and downslope on the welder to regulate the ramp up and ramp down of the arc following the relay opening the button circuit.

I'll post up some photos of welds I make later in the low cost welding section. This hack is kind of a crutch. Novice welders can just lay a filler wire down in the gap to be welded and turn on the pulsing torch and the action of the pulses combined with the translation of the hand will create a "stack of dimes" weld. No necessarily stronger or better than manual welding but easier since it requires less manual dexterity and muscle memory. Real welders use a combination of torch translation, pedal control of current and dabbing rhythm with the filler rod to create this effect - a skill that takes many hours to build up.

The modules. $6 worth. Starting clockwise from the top - the connections for the welder, a 5V relay, a square wave generator board, a voltage booster, lithium ion vape battery, on/off switch and usb battery charger. Note all prebuilt and wired with simple wiring. All you have to pay attention to is positive, negative, input and output.

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Since I'm going to be welding with this I wanted a sturdy box. I 3D printed this three piece enclosure to hold all the modules. Baby CAD design using Tinkercad.

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All the items fastened to the box and glued or screwed down.

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Wired up! Just connect up the modules. Just like dot to dot. I rewired it with shorter connections for neatness.

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Glue the enclosure together. Hopefully this lasts a long time and I don't have to tear into it. The battery is rechargeable so ideally this is sealed for good.

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Finished unit. Ready for pulse welding. I'll post up my welds later in the minimalist welding section.

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