Show HN: I made my own TRMNL e-ink device | Hacker News Reader

Show HN: I made my own TRMNL e-ink device

stavros.io

85 pointsstavros24 comments

> $20 “developer edition” license which “unlocks their API”. I expected this upgrade to give me API access so I could retrieve the image that’s displayed of my device, but that’s not actually the case, and you need a $50 “virtual device” license for that.

I cannot find a mention of the developer edition. I own a TRMNL and use the api for free (I assume because I have a device) and then they offer a lifetime $50 license to use their backend with your own device. I think that's fair.

Also, I don't quite understand their back ordering information. I ordered mine and got it less than a week later even though they said it was back ordered.

That option is for when you add it to your cart. You get API access with the device because you have one, but AFAIK you can't develop plugin without the dev option? I don't know, I'm confused :(

Interesting, I have developed plugins for my TRMNL and I only paid for the device.

Or at least I've developed HTML-based views that are custom (I think that's "plugins") that are displaying on my device.

Hm :/ I wonder why I paid the extra $20, then...

TRMNL's site seems to think there is not a cost-savings to build-your-own. They don't appear to include the licensing cost though. From their site:

> Making your own TRMNL from scratch is not an economically rational decision, but rather a labor of love. Our own team learned this the hard fun way while building v1 over 7 months, from Dec 2023 to July 2024.

> Here's what you can expect to spend per component:

> • Battery, $5 (unnecessary if you prefer plugged in)

> • EPD screen, $65 (see the Waveshare 7.5" on Amazon)

> • Microcontroller, $3-50 (depends if you build/solder yourself or leverage a PCB prototyper)

> • Enclosure/case, $3-20 (design + 3D print yourself or use a print farm)

Yeah, my BOM was $20 for the driver and $50 for the screen, plus $50 for the TRMNL license. About the same as the TRMNL I bought, in the end, though as you say the license is a big part of it.

My worry is about my lifetime license eventually turning into a subscription requirement.

> I could have my own TRMNL for under $80, or, if you factor in my time, around $5,000, which is a bargain

I love the self awareness.

I'm trying to be better about factoring in my time, largely unsuccessfully.

E.g. I just spent $200 of my time trying to trade in an iphone at the apple store (the Apple Store sucks now and has terrible processes). Value of trade in: $200

The trick is that, if you're enjoying the process, the cost is negative! Trading in an iPhone doesn't sound very enjoyable, but to each their own.

stavros is one of my favourite posters on HN, and the writing on his site is full of beautiful turns of phrase like that.

> The Timeframe is a beautiful, battery-powered, high-resolution e-ink device that sits on my desk and reminds me of the inexorable grind that saps my creativity and drains me of the will to live.

From https://www.stavros.io/posts/making-the-timeframe/

edit: Ever since I read the Timeframe article I've been itching to do the same thing myself, but I suck at these things so worry that I'm just going to end up with more piles of electronic parts in my cupboard of broken dreams.

Speaking of a beautiful turn of phrase: "...more piles of electronic parts in my cupboard of broken dreams."

I call it the "cupboard of infinite possibilities".

Email me and I'll help you!

Have mine in the hopes of making your itch unbearable: https://imgur.com/a/diy-automatic-e-ink-newspaper-using-rust...

You can do it! :-) Also happy to help if you have questions.

Oh I had seen yours! What a fantastic project, well done. Beautiful result.

Thanks!

I'm currently making something inspired by your Timeframe, but using an OLED panel, as a 2nd screen for my desk - but almost the same form-factor and a similar design.

I'm trying out a faux 3D-printed wood process with wood powder-infused PLA, sanding and staining, and a faux wood grain I baked into the geometry using a displacement map, though. Hoping to make it all posh.

That sounds fantastic! I'd love to see updates, we have a maker Discord server I can invite you, if you're interested, or it would be fun to just email! My email is in my profile.

How did you come to the $200 figure?

Your time does have value, but it’s in terms of opportunity cost, not hourly wage. Presumably you wouldn’t have made $200 had you not gone to the Apple Store (unless you went when you were supposed to be working and have a job where that time becomes unpaid).

Not the OP, but I just figure that I could be contracting somewhere at any point, really, so each hour costs me my fee.

I'm paid by the hour and the Apple Store is a block away from my place of work, so in this particular case it is pretty clear cut. I realize it is different for people paid a fixed annual salary.

Although in hindsight it probably felt like I spent more time there than I actually did. I think the $200 is fair given that I would normally be quite willing to pay to avoid that kind of unfortunate circumstance.

And of course that leaves out the complication of pre- vs post-tax wages, retirement savings, etc.

You can always trade in by mail. I just did it for my M1 Air. I still need to drop it off at UPS, but no driving to the mall, parking, and waiting in line.

This is also why I buy almost everything from Amazon. Their returns process is worlds ahead of every one else. It also doesn't hurt that drop-offs are at grocery stores.

My problem is I initially had a trade in by mail in process. But since I have to walk by the apple store daily on my way to work, it was one of those rare moments where mail was actually less convenient. And I was concerned about the mail in return contractor deciding the phone is worthless (it happens).

Apple made me call to cancel the trade in, then said they could do it in store. They could not, not then, not an hour later, not days later.

Internet and apple store employees said it should be fine. I guess they don't make geniuses like they used to.

This is neat--what's the typical refresh rate/update speed for the image service?

Is the API is basically "Push PNG to server, PNG displays on whiteboard?"

No, TRMNL generate the images themselves. The device requests the image every so often (with an interval configurable by the server). They've (understandably) built the firmware to be pretty specific to their service, though you can build your own server for it as well (it's just a JSON response with the image to fetch).

The API is:

You write HTML templates (that are stored on their servers) then can post data to them (or have them poll an endpoint to get the data) to "merge" into the template.

Think:

    <h1>Hi {{ username }}</h1>
    <div>You have {{ openPRCount }} open PRs</div>

And you need to provide (via push or pull):

    {"username": "joshstrange", "openPRCount": 10}

That might not be the exact syntax (I wrote my custom plugin a month or two ago and haven't touched it since).

They provide a "UI Library" (Design System) [0] to give you building blocks of UI to use if you want.

It made it really easy to get started. They limit to 1 screen update every 15min (that is the fastest you can have the screen update). But you can press the restart button on the back of the device to force it to update, you might need to force your plugin to re-generate the image before you do that.

If you want to flash your own firmware you can lower that (at the expense of battery life) value or even have it call out to your own server that can do whatever you want.

[0] https://usetrmnl.com/framework

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