<p>I finally built a Raspberry Pi project my wife loves: an e-ink train and weather tracker! If you want to build one yourself, <a href="https://github.com/SamBroner/subway-e-ink-tracker">the Github &#x26; instructions are here.</a></p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="one"><img src="/posts/raspberry-pi-train/kira-leaving.jpeg" alt="" /></div><p>Kira will be jogging to the night shift!</p></div><p>Over the past few years, I've been on something of an e-ink journey.  I started with a <a href="https://sambroner.com/posts/raspberry-pi-weather">weather and news display</a> (still the only post on my website that regularly gets organic traffic.) While I loved it and it looked great, a phone is a better way to check the news, and the weather only gets checked once a day. Then in 2022 while at MIT I built <a href="https://x.com/SamBroner/status/1602137871523143680/video/1">Jarvis, the e-ink voice-to-image display</a>. Jarvis was a great party trick — say, "Hey Jarvis, paint me an elephant on a bowling ball in Times Square" and watch as the image gradually appeared. Notably, this was before ChatGPT, when people were still impressed by AI!</p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="two"><img src="/posts/raspberry-pi-train/weather.jpeg" alt="" /><img src="/posts/raspberry-pi-train/jarvis.jpeg" alt="" /></div><p> Jarvis live demo is better! </p></div>
Then over Thanksgiving, I had some free time, a basket of spare parts, and the itch to code and build something physical. So here we are with the e-ink train and weather tracker.
<p>The idea is simple: Every morning, my wife and I take the inbound F or G subway lines to work from a stop that's a 2-minute jog or a 6-minute walk from our house. I love the NYC subway and it works incredibly well, but the trains come <em>often</em> and <em>predictably</em>, not <em>on-a-schedule</em>. So every morning we're calling out, when's the next G, when's the next F — and one of us pulls out a phone for the MTA app or Google Maps and yells back the upcoming train times. Then we time our morning routines to either stretch for a train in three minutes or slow down for a train in ten.</p><p>The subway and weather tracker makes checking train times much faster and calmer than pulling out a phone. Since it's centrally located in our home, someone is always close enough to glance at it.</p><p>The subway times reported by the <a href="https://www.mta.info/developers">MTA API</a> are reliable once the train is within a few stops or 15 minutes away, with precision increasing as the trains get closer. Having the train times on the wall lets you check how your morning routine is developing against the train schedule as the departure time gets closer.</p><p>Best of all, Kira loves it! This goes on my DIY pantheon along with adding legs to her dresser to make it a better height and fixing a towel rack right before she hosted her colleagues for a book club.</p><p>If you want to build one yourself or better understand the project, I'll dive into some editorial and gotchas below. The practical instructions, parts, and code live in this <a href="https://github.com/SamBroner/subway-e-ink-tracker">GitHub Repo</a>.</p><h2>Description &#x26; Features</h2><p>The train &#x26; weather tracker is built on a <a href="https://www.waveshare.com/product/displays/e-paper/9.7inch-e-paper-hat.htm">9.7" 1200x825 E-Ink display</a> attached to a <a href="https://www.raspberrypi.com/products/raspberry-pi-4-model-b/">Raspberry Pi 4b</a>. The display is split into four parts: a header, with date, time, and a live second hand to indicate liveness; a train tracker; the commute weather; and a "weather bar" displaying the next 12 hours of weather. The main focus of the layout is the train tracker, which shows the upcoming 30 minutes of inbound F &#x26; G trains.</p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="one"><img src="/posts/raspberry-pi-train/raw-display.jpeg" alt="" /></div></div><p>The display sits in a laser cut mat board with black ridges sized to hide the black border of the e-ink display. The mat board sits in a 8.5" x 11" cherry frame that is 1.5" deep to allow the raspberry pi to be backmounted while the frame is still flush to the wall. We hang the display next to the door above a key holder, which is generally the right place for it, but also helps hide the power cord.</p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="one"><img src="/posts/raspberry-pi-train/back-of-frame.jpeg" alt="" /></div><p>Not pretty, but it works</p></div><h2>Project Details</h2><p>The software portion of the project is manageable although there are some gotchas when programming against the Waveshare e-ink hat in particular. We have a modular architecture with a clear separation of concerns:</p><ol><li><p>Display Engine: Renders the layout to the display, supporting communication with the physical e-ink display or rendering a png for non-raspberry pi development</p></li><li><p>Layout System: A pretty hacky visual arrangement of the elements. It'd be fun to do something more sophisticated here (e.g. a html renderer), but 🤷‍♂️. This will likely require the most work if you want to modify the project</p></li><li><p>Data Services: Fetch &#x26; process (this is important!) train arrival from NYC Transit GTFS feeds + get the weather forecasts</p></li><li><p>Application Controller: Orchestrate the event loop and subscription model to drive updates to the display</p></li></ol><p>The biggest technical constraint is the update rate to the e-ink display. The display supports multiple update modes with different tradeoffs and <em>can</em> manage sub 500 ms updates, especially for partial updates, but a faster refresh results in fuzzy characters and substantial ghosting that looks pretty bad. The bigger issue is that overloading the display causes it to crash, which requires a full reset.</p><p>After some testing, I chose a hybrid display update strategy.</p><p>Every second, the pixels around the seconds &#x26; minutes digits of the time are rerendered with the display's fastest partial update mode to make it clear that the display is functioning as expected.</p><p>When there is an update to one of the next two train times (these matter more than trains 30 minutes away), there is a fast-full display render — all data is updated at this point, but only new arrival times for one of the next two trains will drive the update.</p><p>On the hour, the display does a deep full-screen render to sharpen the characters and remove ghosting.</p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="one"><img src="/posts/raspberry-pi-train/mode-summaries.jpeg" alt="" /></div><p>Honestly, you gotta experiment to understand how these will look </p></div>
Doing deep full screen renders can be jarring — it results in a black and white flash that attracts too much attention to the screen — but once an hour is a fine cadence. For the train times, a fast-full display render works better than a partial refresh because of the layout. The fast partial render cuts across elements, drawing more attention to the refresh than a full refresh. This could maybe be improved through more purposeful partial refresh rectangle selection, but the current solution works well.
<p>The framing was tricky because I wanted something nice, but without breaking the bank. I'm not great at woodworking and I also didn’t want to spend $300-$500, which was the range of quotes (FWIW, I have been trying to find a low cost framing solution for these broken glass pieces for years — let me know if you have any ideas). The e-ink display is awkwardly sized due to the connection cables and drivers. The display surface also has a fine looking, but inelegant border that should be covered. After talking to a few framers, one of them suggested I buy <em>just</em> a custom mat. The mat hides the display, Raspberry Pi, and cabling, but more importantly the outside of the mat is right sized to fit into a standard-sized frame.</p><p>The finished product sits neatly beside our door, providing the exact information we need at just the right time each morning. I've written before about the "agency gap" — the gap between what people do and what would be easy, but useful to do. This project is a bit more involved than that, but at ~20 hours of work, it was worth it to me. I built something that solves a daily need, we actually use it, guests talk about it, and it looks great.</p>


A dashboard with the weather forecast and top headlines is an easy, but useful little project.

Building an E-Ink Train & Weather Tracker

<p>Very fun weekend project. With E-Ink displays coming down in price and Raspberry Pi’s getting cheaper, I wanted to play with these new toys! A simple dashboard with the weather forecast and top headlines is an easy, but useful little project.</p><p>Ours is now hanging up in the kitchen...</p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="one"><img class="half" src="/posts/raspberry-pi-weather/Vertical.JPG" /><img class="half" src="/posts/raspberry-pi-weather/Side_Angle.JPG" /></div><p>Almost arty photos</p></div><p>If you just want to see the code, check out the <a href="https://github.com/SamBroner/e-ink-weather">repository here</a>.</p><p>Read below to put this project together yourself!</p><h2>Supplies</h2><ul><li>Raspberry Pi w/ Wifi</li><li>MicroSD w/ Raspbian</li><li>E-Ink Display</li><li>2.5A Micro USB charger</li><li>(Optional) Keyboard, Mouse, Display, &#x26; Mini-hdmi adapter or cable</li></ul><h2>Getting Started with your Raspberry Pi</h2><blockquote><p>This is my process for setting up a RaspberryPi… if you know what you’re doing here, skip to the next section</p></blockquote><h3>Turn on the Raspberry Pi</h3><p>There’s been many guides written here (<a href="https://projects.raspberrypi.org/en/projects/raspberry-pi-setting-up">some</a><a href="https://www.tomshardware.com/reviews/raspberry-pi-set-up-how-to,6029.html">of my</a><a href="https://www.instructables.com/Ultimate-Raspberry-Pi-Configuration-Guide/">favorites</a>), but here’s the sparknotes.</p><ul><li><a href="https://projects.raspberrypi.org/en/projects/raspberry-pi-setting-up/2">Download Raspbian onto an SD card</a></li><li>Plug that SD card in</li><li>Plug in a power cable</li><li>Plug in keyboard, mouse, and display</li></ul><blockquote><p>It’s easy to get lost in the weeds when you're just getting started.
Just follow one guide and keep going.</p></blockquote><p>I like to get the <a href="https://www.raspbian.org/">Raspbian</a> UI up and running so I can get readjusted to the Raspberry Pi environment and tools.</p><h3>Configure the Raspberry Pi</h3><p>Next we’re going to make changes to the raspberry pi configuration</p><ul><li><a href="https://www.raspberrypi.org/documentation/configuration/wireless/">Connect to the internet</a> - For API access and to enable github and other developer tools</li><li><a href="https://www.raspberrypi.org/documentation/usage/gpio/">Enable GPIO pins</a> - For the E-Ink display connection</li><li><a href="https://www.raspberrypi.org/documentation/configuration/security.md"><strong>Change password</strong></a> - So we don't get <em>HACKED</em></li><li><a href="https://www.raspberrypi.org/documentation/remote-access/ssh/">Enable remote SSH</a> - For my preferred developer tooling setup</li></ul><h3>Connect via SSH Using VScode</h3><p>Let’s connect the RaspberryPI to VSCode via <a href="https://code.visualstudio.com/docs/remote/ssh">Remote-SSH</a>. This is my personal preference. It just works so dang well!</p><p><a href="https://www.raspberrypi.org/blog/coding-on-raspberry-pi-remotely-with-visual-studio-code/">Here's a guide to getting connected using VSCode.</a></p><p>So download and install VSCode and install the "Remote-SSH" plugin, then connect to the RaspberryPi by hitting CMD-Shift-P and typing in Remote-SSH. Connect to host, where the host is "RaspberryPi.local"</p><p>In my experience, Remote-SSH can work with a RaspberryPi 2b+, but remote shell works better with the 3 or newer. Much less stuttering, disconnecting.</p><h2>Connect your E-Ink Display</h2><p>I'm using the <a href="https://www.waveshare.com/product/displays/e-paper/epaper-1/7.5inch-e-paper-hat-b.htm">WaveShare 7.5in Red/Black/White display</a>. The RaspberryPi hat pushes directly onto the GPIO pins of the RaspberryPi.</p><p>To test the connection, I used the <a href="https://github.com/waveshare/e-paper">WaveShare github repository's</a> Python test scripts. They're moderately well documented, so you can just run the test script appropriate for your WaveShare display.</p><h2>The Code</h2><p>The interesting part of this project is the GitHub repository. You can check out my code here: [https://github.com/SamBroner/e-ink-weather)[https://github.com/SamBroner/e-ink-weather]</p><p>To get weather information, I used <a href="https://weatherapi.com/">https://weatherapi.com/</a>. To get News, I used <a href="https://newsapi.org">https://newsapi.org</a>. If you use my repo, you can clone and put your API tokens in the <code>.env</code> file.</p><p>It's relatively well documented, but tweet at me if you have issues and I'll update the documentation. (<a href="https://twitter.com/SamBroner">@SamBroner</a>)</p><h2>Hanging &#x26; Framing</h2><p>Ultimately, I wanted this to hang in the kitchen, so I found a cheap Shadow Box frame at a used goods store near my house.</p><p>I cut an opening for the ribbon cable to go from the front of the matting to the back, then glued the display &#x26; the RaspberryPi to opposite sides of the backing.</p><h2>Conclusion</h2><p>Fun project. E-Ink is great and reduced prices should lower the barriers to projects like this.</p>


A simple dashboard with the weather forecast and top headlines is an easy, but useful little project.

Building an E-Ink Weather & News Display

<p>There’s a small art gallery nestled between an alright Thai place and a yuppy cupcake shop in
Seattle’s Capitol Hill. The pieces are amazing shattered glass, perfectly reconfigured. I figured I
should try it.</p><p>Here’s my first attempt alongside Cassandria Blackmore’s excellent work.</p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="two"><img src="/posts/shattered-glass-1/image1.png" alt="" /><img src="/posts/shattered-glass-1/image2.png" alt="" /></div><p> Guess which is which? </p></div><p>After a few attempts, I engineered something a bit more respectable. I’ll keep iterating on this, but I
don’t think I’ll quite replicate Cassandria. I’ll just have my own “inspired”
style.</p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="one"><img src="/posts/shattered-glass-1/image6.png" alt="" /></div></div><h2>Attempt #1</h2><h5>Maybe it'll work?</h5><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="one"><img src="/posts/shattered-glass-1/image1.png" alt="" /></div></div><p>I went to the local Blick and bought some reasonable seeming supplies.</p><ul><li>.5” Foam Board</li><li>Acrylic Paint</li><li>Acrylic Medium (glueish stuff?)</li><li>Picture frame glass</li></ul><p>I figured I could paint the glass, then use the Acryclic Medium to glue the glass to the board. A quick
shatter, and I’d be done.</p><p>Each step of this was harder than expected.</p><p>Because the unpainted glass faces the viewer, the first layer of paint is the most obvious. I had some <strong>ugly</strong> early attempts.</p><p>Acrylic Medium is a bad glue for this job. The shattered glass is basically pulling itself off the Foam Board.</p><p>Most importantly, picture glass is <strong>not</strong> what Cassandria uses! It shatters into shards, not the glittering fragments pictured above.</p><h2>Attempt #2</h2><h5>Figure out the glass</h5><p>What glass shatters into a million pieces? Car glass! That is... tempered glass. Tempered glass is regular glass that is heat treated to give it opposing compression and tension. To simplify, a piece of tempered glass is strong while intact, but, once broken, the opposing forces rip the glass apart.</p><p>So I went on Craiglist and found some old tempered glass shelves to
destroy!</p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="one"><img src="/posts/shattered-glass-1/image7.png" alt="" /></div></div><p>This worked much better. The tempered glass creates the pattern we’re
looking for.</p><p>I used the leftover paint and some left over cardboard and substituted our new glass. Everything worked, but
shattering tempered glass is hard (and <strong>dangerous</strong>.) I had to really hammer the corner
for this to work.</p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="one"><img src="/posts/shattered-glass-1/image8.png" alt="" /></div><p>Pictured: An idiot (me) wearing non-protecting sunglasses and sound canceling headphones.</p></div><p>At this point, issues with the cardboard became obvious. My tempered glass was pretty heavy and without the rigidity of the glass or foamboard, the pieces flopped apart.</p><p>At this point though, I thought I should focus on the paint.</p><h2>Attempt #3</h2><h5>Focus on the paint</h5><p>I watched like 30 videos on how to blend paint. They all intend for the blended paint to be seen from the
painted side of the piece (we need the other side to look blended.) It turns out this wasn’t much harder,
but I had to use a sponge to scrub the paint off the glass repeated in order to get a consistent blend.</p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="one"><img src="/posts/shattered-glass-1/image5.png" alt="" /></div></div><p>It still didn’t quite work, but closer.</p><p>I also added safety glasses, earplugs, gloves, shoes (not pictured), and wrapped the glass in trash bags.</p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="one"><img src="/posts/shattered-glass-1/image4.png" alt="" /></div><p>You can hear the tempered glass continue to pull itself apart!</p></div><p>At this point, the foam board became a problem. It’s too thick to fit into a normal frame and it’s
still not rigid enough. Also, my hacked Acrylic Medium &#x26; Glue still didn’t really hold up. You can see
the edges crumbling away.</p><div style="box-sizing: border-box;" class="imageGallery"><div style="box-sizing: border-box;" class="one"><img src="/posts/shattered-glass-1/image3.png" alt="" /></div><p>You can hear the tempered glass continue to pull itself apart!</p></div><h2>Attempt #Next</h2><h5>Tie it all together</h5><p>I’ll be trying this again in the coming weeks. I believe I’ll need these supplies.</p><ul><li>Tempered Glass</li><li>Stiff Sheet Metal (Backing Board)</li><li>Good Epoxy Glue</li><li>A Drill</li><li>Safety Equipment</li><li>More space</li></ul><p>With a drill, I can break the glass more accurately and without throwing out my shoulder.
Hopefully the metal sheet will be stiff enough and thin enough to put the combined piece in a frame. I’m
also hoping the epoxy will bind better. In all my prior attempts there were still fragments falling off.</p><p>We’ll see!</p>


Making art with paint, tempered glass, and a hammer.

Sam Broner

Software in NYC & Online

Posts about Physical