Comment by cactus2093 | Hacker News Reader

Comment by cactus2093 | Hacker News Reader

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On a similar note, does anyone know of good resources for beginners for prototyping all the way through small-scale manufacturing of an embedded device?

As a web & backend developer who likes to tinker with Arduino/Teensy style projects, I've always been curious what all would be involved in actually getting some units manufactured, like for a small kickstarter run or something. It seems pretty doable these days to get pcb boards printed and even assembled once you have a final design. What I haven't been able to find much of, is advice along the lines of going from a prototype board like an Arduino or Teensy system, to a productionalized system in terms of both the software and hardware - what platform is easiest to build on (like this advice to use a Linux-based system if you need any networking), how to hook up a bootloader, how to build a system that allows users to update firmware for future bugfixes or features, etc. plus I'm sure there are a million other unknown unknowns I would never even think of.

I made a video course for getting up and running with KiCad, the open source electronics CAD program: https://www.youtube.com/playlist?list=PLy2022BX6EspFAKBCgRuE...

If you're looking at broader focus on building hardware, Contextual Electronics helps to fill out some of the other elements you're looking to do. As luck would have it, I just started a new course today (no joke) where I'm showing how I'm designing a Raspberry Pi HAT with cellular and Bluetooth capabilities, which I'll be selling and using as a reference design for my hardware design consulting business.

Chris, I love your work and the AmpHour podcast! Thanks for working to share your knowledge with others, I especially enjoy the episodes where you spend the entire episode interviewing someone in the industry

Glad to hear it! I love making The Amp Hour and am flattered the people listen on a regular basis. Thanks for being part of the community!

How does KiCAD compare to Eagle? I find it being built in to Fusion 360 now (since Autodesk bought it) pretty compelling, but I haven't actually used any schematic/PCB CAD software since that I don't think.

I think they have been keeping apace for the most part, but the integration of F360 is a really nice feature if you do a lot of mechanical/electrical integration. I think it might be a bit overplayed, since my designs are usually, "Here's the mechanical space you're allotted, it's probably not going to change", but that's not the case for everyone.

As for KiCad, the most recent release (5.1.x) have been really stable and introduced a ton of features over the series 4 release. Like anything, once you're used to the methods, it's hard to get an objective look on how things work but I can tell you that I use KiCad for all of my professional design work and it has served me very well.

One thing I continue to be excited for is the extensibility of KiCad, since Python scripting is a main feature of KiCad (though the program is written in C++). This has developed a wide range of user plugins and scripts that have opened up some awesome new features.

One of my favorites is the Interactive BOM plugin, it's really quite amazing. Here's a user showcasing it on twitter: https://twitter.com/arturo182/status/1254376168322670593

Take a look at Particle. They sell dev boards, but also have excellent documentation on how to scale (at least they used to, I'm not sure where it's gone now - have a look in the datasheet section) - obviously they want to get you into their cloud fleet management platform, but it would be a tempting solution for me. For example, you buy the dev board (fairly cheap), they also sell the SoC (cheaper when you buy in bulk) and have design guidelines for making your own boards.

The boards themselves are quite nice. It's an Arduino-like stack and you can always code in C++ if you need the STM32 capability underneath. The main stack is also open source I think.

Doesn't really cover much on the mechanical side, e.g. enclosure design. That's a whole different game and that's where people lose a lot of money - if you mess up an injection mold for example.

https://www.particle.io/

I've done a small run of ~100 devices.

It was basically the same process as looperhacks: hook stuff up on a breadboard, turn that into a prototype PCB design, iterate on prototypes if there are problems, then just put 100 on the order form instead of 5 when you send it to the manufacturer.

You asked in the other comment about flashing and that depends. For me, my project was basically just a motherboard for an ESP32 dev board, which would serve as the logic controller. Since it has a micro-USB port and there were only 100 of them, I just flashed it from my laptop the same as any dev board.

For larger scale manufacturing, you can have the flash written in advance, before manufacture or put some exposed contacts on your board that can be reached with pogo pins and write your flash through those pins.

You can also outsource all of this to a contract manufacturer like Seeedstudio [0].

As for updates, the ESP32's software has built in OTA functionality that you can configure however you please. My boards are connected with MQTT over WiFi anyway so I added a simple "update now please" command that triggers the OTA. Aside from that you could add a USB port or stream the OTA over bluetooth from a smartphone.

[0]: https://www.seeedstudio.com/propagate/

Lately I've been prototyping a small board with my goal of maybe 10 units built. For me, the process is literally putting it together on a breadboard to check if it works, then design a PCB and send it to a Chinese manufacturer. Repeat if your PCB design is faulty. (Do double check your design though, you don't want to pay for new boards and shipping every other week)

I guess one big gap for me is just the build process of how to even load code onto the device to be executed, and what type of EEPROM or flash storage or other components are required for that, once you've removed the training wheels of the plug and play dev environment.

It really depends on what you're using. Most microcontrollers don't require external memory to store their program because it's stored in on-chip flash memory. Additionally, you can generally order microcontrollers from a distributer that are already flashed with your program. Though this may require ordering 1000+ units. If that isn't an option then you'll have to ensure that the pins used for programming are exposed in some fashion and then you'll flash it. The exact details are dependent on exactly which microcontroller and toolchain you're using.

It mostly comes down to reading the documentation for the specific microcontroller that you're using.

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