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I learned PCB design, 3D printing and C just to listen to music

pentaton.app

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Re: I learned PCB design, 3D printing and C just to listen to music

#31

Post by peteforde »

turkeygizzard wrote: post #26
matheusmoreira wrote: post #20

> I never did this before so there was plenty to learn, from basic electronics and magnetics to high-speed signal routing. How did you learn this? As a hobbyist I found hardware to be quite impenetrable, given the hard mathematics and physics requirements. My attempts to learn this essentially degenerate to taking an informal engineering course. It quickly becomes clear that I'm years away from making something, and…

I was going to say, AI has really enabled my hardware projects recently. I've found incorrect output is less common with the newest models - and they're capable of drawing decent diagrams too which can really help me sanity check some of their ideas. I've also had some success with asking it to cite sources where possible, so I get lots of useful links into robotics forums like chief delphi and similar which also hel…

I have serious beef with ChatGPT's text-based circuit schematic drawing abilities. Even though the model itself appears to be fully coherent about the big and little picture aspects of whatever's "on bench" I have wasted too much time trying to parse its attempts to draw circuits. I consider them actively harmful in their current form. I quietly hope that one of the LLMs will start actually generating netcode that can be pasted into KiCAD, or even rendering circuit snippets inside of the chat stream properly.

I've seen KiCAD running in the browser, so it's not like this isn't completely doable. It's just a question of resource allocation.

Re: I learned PCB design, 3D printing and C just to listen to music

#32

Post by interfeco »

peteforde wrote: post #30

This is really cool. I would love to switch from using the SoM I'm currently using to the Radxa CM3 but I cannot find even a single unit actually available for purchase on any of the "international" distributor options. Can you speak to how you're sourcing these, and from where? (And would you sell me one?)

I buy them on AliExpress.

Re: I learned PCB design, 3D printing and C just to listen to music

#33

Post by maples37 »

matheusmoreira wrote: post #20

> I never did this before so there was plenty to learn, from basic electronics and magnetics to high-speed signal routing. How did you learn this? As a hobbyist I found hardware to be quite impenetrable, given the hard mathematics and physics requirements. My attempts to learn this essentially degenerate to taking an informal engineering course. It quickly becomes clear that I'm years away from making something, and…

About a year ago, I found a YouTube channel[0] which consists mostly of a really smart guy (with a proper background in electrical engineering) buying cheap electronics from eBay/Temu/AliExpress/etc, taking them apart and identifying the components, then reverse-engineering them. (Often followed by a discussion of how much better of a product it could be if the manufacturer hadn't cheaped out on a two-cent component.)

I'd previously had a barebones interest in electronics (think: kits with LEDs and buzzers in like 3rd grade), but listening to his discussions and explanations of how these things worked gave me a fairly decent understanding of how some basic electrical principles work.

I also recently watched a video series[1] that explained how microcontrollers (specifically the ATMega328, the one powering the Arduino) work, from a very low level that I've always wondered about. The key part of that series, for me anyway, was getting the chip off of the Arduino PCB and onto a bare breadboard. From there I went and read/skimmed the ATTiny85 datasheet[2] (a very popular "baby brother" chip to the ATMega328) which also helped me understand how these chips do things like PWM on a low level.

I've built one project (a simple PWM dimmer based on a potentiometer) and am working on another (designing a PCB with KiCAD[3] to replace the circuit board for a battery-powered LED lantern, so I can design my own sequencing interface for what happens when you press the singular button), and it has been quite the learning experience, but one I've greatly enjoyed!

[0] https://www.youtube.com/@bigclivedotcom, also at https://odysee.com/@bigclivedotcom:0d

[1] https://www.youtube.com/watch?v=tBq3sO1Z-7o&list=PLNyfXcjhOA...

[2] https://ww1.microchip.com/downloads/en/devicedoc/atmel-2586-...

[3] This comment is long enough already, but KiCAD is a fantastic piece of FOSS software. It's a full schematic/PCB design suite, and there are plenty of tutorials all across the Internet for it.

Re: I learned PCB design, 3D printing and C just to listen to music

#35

Post by pedda8862 »

peteforde wrote: post #31
turkeygizzard wrote: post #26

Earlier quoted context omitted.

I was going to say, AI has really enabled my hardware projects recently. I've found incorrect output is less common with the newest models - and they're capable of drawing decent diagrams too which can really help me sanity check some of their ideas. I've also had some success with asking it to cite sources where possible, so I get lots of useful links into robotics forums like chief delphi and similar which also hel…

I have serious beef with ChatGPT's text-based circuit schematic drawing abilities. Even though the model itself appears to be fully coherent about the big and little picture aspects of whatever's "on bench" I have wasted too much time trying to parse its attempts to draw circuits. I consider them actively harmful in their current form. I quietly hope that one of the LLMs will start actually generating netcode that ca…

Without any deep knowledge, I was able to build at least a working board with a mcp server [1]. It’s always about the interface. I had to solder a few parts. Yes there where a lot of vias placed. Nice grid but it worked.

[1] https://github.com/mixelpixx/KiCAD-MCP-Server

Re: I learned PCB design, 3D printing and C just to listen to music

#36

Post by matheusmoreira »

qup wrote: post #22
matheusmoreira wrote: post #20

> I never did this before so there was plenty to learn, from basic electronics and magnetics to high-speed signal routing. How did you learn this? As a hobbyist I found hardware to be quite impenetrable, given the hard mathematics and physics requirements. My attempts to learn this essentially degenerate to taking an informal engineering course. It quickly becomes clear that I'm years away from making something, and…

Or, you could make some mistakes.

Those are expensive, especially in my country where the taxes double the cost of everything.

Re: I learned PCB design, 3D printing and C just to listen to music

#37

Post by Aurornis »

skippyfish wrote: post #9
mananaysiempre wrote: post #5

> Once I had the design [of the enclosure], I tried to 3D print it on my brand new 3D printer, which turned out to be a disaster. Took me some time to learn more about designing for manufacturing, especially for 3D printing. Would have been nice to hear how specifically it was made to work in the end. > Turns out, cross-fading two 4MP images at 60 frames per second on a moderately powerful single board computer is no…

Large displays are not driven by a general-purpose CPU that bit-bangs a single serial data line, and never were. They're driven by separate circuitry with direct memory access, often integrated on the die of chips meant for these applications. The actual bus to the display controller may be a parallel dot-clock RGB bus, or an ultra-speed differential multi-lane serial (MIPI DSI, HDMI, etc). And train stop displays ce…

> They're driven by separate circuitry with direct memory access, often integrated on the die of chips meant for these applications

In embedded SoCs the memory bandwidth is often shared between the CPU and the GPU. There is not a separate pool of memory and bandwidth for the GPU.

> The actual bus to the display controller may be a parallel dot-clock RGB bus, or an ultra-speed differential multi-lane serial (MIPI DSI, HDMI, etc).

That’s not what the parent comment is talking about. To get the data into the framebuffer you need to write it first. You also need to read the source images. For blending two images and writing the output, the floor is 3X the total image size every single frame. (Two reads, one write). There are tricks that can be played with frame buffers and scan out blending, but you get the idea.

> And train stop displays certainly don't need 60 fps.

We’re talking about the product in the link, which is trying to blend seamlessly between two images at 60fps.

> The main constraint for high-resolution displays is memory, not CPU clock speed.

I don’t think you understood the problem space.

If you’re doing software blending of 10MB image buffers at 60fps, the CPU can be easily be a bottleneck. You have to ensure the CPU can do enough load operations, math on the loaded data, and store operations to get it done in 16.7ms. Ideally you have a GPU, but if you don’t then you need to pay close attention to optimizations and special instructions to get it done within the frame budget and also allow some cycles for all of the other work the app has to do.

> Your (odd) 1920x1920x24bpp frame buffer takes up more than 10 MB.

The 1920x1920 size came from the article. Parent commenter wasn’t making up odd sizes, they were responding to the article.

Re: I learned PCB design, 3D printing and C just to listen to music

#38

Post by egypturnash »

> Turns out, cross-fading two 4MP images at 60 frames per second on a moderately powerful single board computer is not so easy. I needed to use GPU acceleration to make it happen and look smooth.

fizzle fade, munching squares, horizontal/vertical/circular/pinwheel/etc wipes - anything that lets you replace a small number of pixels in the display buffer each frame.

Re: I learned PCB design, 3D printing and C just to listen to music

#39

Post by peteforde »

interfeco wrote: post #32
peteforde wrote: post #30

This is really cool. I would love to switch from using the SoM I'm currently using to the Radxa CM3 but I cannot find even a single unit actually available for purchase on any of the "international" distributor options. Can you speak to how you're sourcing these, and from where? (And would you sell me one?)

I buy them on AliExpress.

Every variant comes up as not available.

This is the listing, right?

https://www.aliexpress.com/item/1005007516847708.html

Re: I learned PCB design, 3D printing and C just to listen to music

#40

Post by interfeco »

peteforde wrote: post #39
interfeco wrote: post #32

Earlier quoted context omitted.

I buy them on AliExpress.

Every variant comes up as not available. This is the listing, right? https://www.aliexpress.com/item/1005007516847708.html

Yes, this was it, looks like it is gone now. According to the CM3 datasheet [0] "Radxa CM3 will remain in production until at least Sep 2029", so there should be inventory hopefully.

[0]: https://dl.radxa.com/cm3/docs/radxa_cm3_datasheet.pdf

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