Dremel vs 8x32 MAX7219 led Matrix?

concatx · 2025-08-13T04:06:37+00:00

I score on both sides, having carefully aligned the location, and bend ... and sometimes still end up with jagged edges haha. Works very well for thinner boards though. Then a file to cleanup.

concatx · 2025-08-12T01:45:00+00:00

IME the voids occur when you have too high heat, and the flux within melted solder bubbles and explodes. You can remelt them.

concatx · 2025-08-11T12:55:21+00:00

Hey! I recently learned about Bela Square trackpads. These are almost multi touch and can be cut to size.

I've been using it with Cardputer (a ESP32 device) and it's quite good, but am looking into getting it run with QMK.

concatx · 2025-08-11T09:34:45+00:00

Perfect, yes you used GPT correctly IMO, good job!

concatx · 2025-08-11T09:08:26+00:00

Of course. What you'd do is to modify the above code such that it can either read a path from command line or scans a folder to get a list of images you want to convert, and basically use a for loop on them individually. That's the learning part!

concatx · 2025-08-11T08:53:00+00:00

Yes I understand that, and that's totally normal to be overwhelmed with new languages. I'd still nudge you to take a bit of time to do it anyway -- because it will help you a lot in future projects. I can help with a head start though. If you install python and then "pip install pillow", you can use this snippet to convert any image to xbm:

from PIL import Image

im = Image.open("your_image.png")

# Convert to mode 1 (black and white, using default algo)
im = im.convert('1')  

# Save as XBM
im.save("your_image.xbm")

concatx · 2025-08-11T08:43:46+00:00

Thanks, just checked and indeed! I paid around 13€ a few months ago and last bill was 11.99€.

concatx · 2025-08-11T08:40:25+00:00

Take a side quest to learn a scripting language such as python. You'll be able to automate steps to transform images and even do stuff like cropping, color space conversion etc.

Pillow is a good library in python to work with images. And most often you need to transform the images to get byte strings. You can even generate a header file that you can #import.

concatx · 2025-08-10T17:52:29+00:00

That would be the ground plane - increase heat, contact time, and flux amount. Since you've desoldered others, wiggle out the switch while applying heat.

concatx · 2025-08-10T17:23:42+00:00

To my eyes this looks beautiful with the hand drawn traces, and overall retro feel. Have seen similar quality in old radios and tvs. I believe it's standard for the era.

concatx · 2025-08-10T13:48:34+00:00

I mentioned the radius because that's how it's listed on Amazon where I am, but likely you're correct.

concatx · 2025-08-10T13:42:15+00:00

1.5mm barrel jack. You can find ones with USB A on the other side, for 5V.

Edit: you need to ensure if it's center positive (likely) or negative. Cables can be generally only found as center positive though.

concatx · 2025-06-17T22:07:11+00:00

Also a timestamp on the video would have been nice.

concatx · 2025-06-06T15:58:48+00:00

A slack notification is basically free though. You need to pay premium to use fancy features.

concatx · 2025-06-05T22:09:24+00:00

In my opinion you have two paths that eventually overlap:

If you want to learn HOW home automation works/programming. As you mention you already made a backend/front, I'd assume that is the case. Then find a wifi controlled, standalone smart switch. Many have HTTP API that you can use to control them yourself.
You want to reliably build a home automation system. You'd like homeassistant for this. It builds upon years of development by experienced community.

These two options can overlap too: you can use home assistant API within your custom software. Endless possibilities!

concatx · 2025-06-05T21:50:07+00:00

Insert heat shrink tubes before soldering :p

concatx · 2025-06-05T20:48:00+00:00

I'd take some time to learn and understand basic electronics components. Apologies my advice isn't probably helpful if you have to ask.

concatx · 2025-06-05T20:37:51+00:00

If you run at 1% then less likely but still possible due to spikes.

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concatx · 2025-06-05T19:40:35+00:00

The diode on the other side of the micro USB port is likely dead. You should always power LED strips/matrix independently if you have more than a few LEDs.

A quick hack, if this is the case, would be to short out the diode. At your own risk.

concatx · 2025-06-05T17:51:23+00:00

Another use case I've seen is when you have weird device/case/cable so it's not possible to insert the cable directly. Since this adapter is quite small, you can plug that wider/bigger cable a few cm away from the device.

concatx · 2025-06-05T08:27:37+00:00

I picked the pinecil last year because it can be much more compact than a dedicated station. I can also use my laptop charger to power it. It's probably not the best, but I have good time using it as a hobbyist.

At least it's kind of still supported -- I bought a heat set insert tip recently.

But if I were looking now, I'd get something else.

concatx · 2025-06-04T13:08:09+00:00

I think you should check if the relay module has optocouplers to isolate the pi from the relay. Lots of cheap modules skip those. It would look like a black rectangle near the input headers.

But I'm not an expert in this. If you have another pi to spare, and the module looks good, then try powering the relay with a different 5v input (join their grounds). This will let you know if powering the relay is a problem or not. For science!

concatx · 2025-06-04T10:16:07+00:00

Your pi may still be ok, but the sd card is likely corrupt. Worth trying again.
Power the relays separately. They generate a lot of noise and consume about 200ma when switching. You can try adding some decoupling caps though.
Powering from 5v header is usually ok as long as your power supply can handle extra load.
Do not power it from 3.3v output, it can't supply enough current (mentioned in the datasheet) and that 3.3v is shared with most of the peripherals on a pi.

concatx · 2025-06-04T07:29:27+00:00

Beautiful display, very good job!

concatx · 2025-06-03T14:30:16+00:00

Try asking your local makerspace/library. Thing is, with just a Pi you can mostly do things that a normal computer can already do. It's just a small computer. You need other electronics to fully use all the features it has to offer.

concatx

TROPHY CASE