Show HN: I made my own TRMNL e-ink device
(stavros.io)45 points by stavros 10 hours ago
45 points by stavros 10 hours ago
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.
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
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).
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.
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.
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>
{"username": "joshstrange", "openPRCount": 10}
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.
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).
> $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.