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Episode 31 - Help I'm Alive

Welcome to the show

Published: April 6, 2026

In this episode, Tod and Paul share a secondary display for your Bambu Labs 3D printer, a small eink eReader, an open source microcontroller, and more.

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Full transcript available here.

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Show Notes

00:15 BambuHelper (Tod #1)

BambuHelper is a tiny ESP32-powered desk friend to tell you how your 3d printer is doing! It uses MQTT (either LAN mode or Cloud mode) to get your Bambu Labs' printer stats. It shows percent progress, ETA when the print will finish, temps of bed, nozzle, and chamber, and even what type of filament its using.

I finally got a Bambu Labs printer a few weeks ago. The same week, a member of the "/r/esp32" subreddit posted about using an ESP32-S3 "SuperMini" board and a 1.5" square TFT LCD display to pull data from their Bambu P1S printer over MQTT. The build was pretty slick and I bookmarked it to consider later, thinking maybe it would work for my H2 printer. A few days later they posted an update: Surprise, BambuHelper now works for all Bambu printers and it can work either in LAN mode, talking directly to the printer, or in cloud mode where it talks to Bambu's servers over secure TLS MQTT. It's even got a web interface to configure settings and what information to be displayed. And becomes a clock if nothing is being printed.

The build is simple: just eight wires to solder between the ESP32 and display. There's an optional touch button you can wire up, but I don't think it's needed. They also designed a nice 3d-printed. It's got a nice minimal aesthetic, almost retro computer inspired, and is thoughtfully designed by assuming your board already has the header pins soldered. Perfect if, like me, you start out prototyping on a breadboard and then want to use the same hardware for the finished project.

I've got a breadboard build running right now and it's pretty useful. While you can get all this information from the "BambuHandy" app on your phone, I am a big fan of ambient displays. This is going in the house so I can tell at a glance what the printer in my workshop is doing. I'm thinking of making an alternate case that's wall mounted to go on a corkboard.

An outstanding question for me about BambuHelper is: how does it deal with error or warning conditions? Jammed filament, open chamber door, etc. I've not tested that yet, and I come from more than a decade of 3d printing, so I'm used to printers failing as much as them working.

And while I've been pondering all this, our Paul here writes two incredible CircuitPython tools: CircuitBambu, a CircuitPython take on BambuHelper, and more generally a bambulabs CircuitPython library for anyone to get info and interact with a Bambulabs printer in CircuitPython. Super neat and I can't wait to play with it. I'm honestly more interested in modding CircutBambu to work with my one of my "favorite ESP32 dev boards" mentioned in previous episodes, since they have built-in displays. No wiring needed! Thanks Paul, I can't wait to try out your code.2

5:56 OpenScan (Paul #1)

OpenScan is a low-cost and high quality 3D scanner that you build yourself that is open source and modular.

8:53 Xteink X4 eink ebook reader (Tod #2)

Back in February I saw some folks on Blueksy who had a tiny eink book ereader that could magnet to the back of your phone. It was exceedingly simple, having only four buttons, no touchscreen, and explicitly just rendered epub-formatted books you loaded via a micro SD card. I've wanted to try a proper ereader for a while but didn't want to get sidetracked by (or pay the expense of, or pay Amazon for) something like a Kindle. This little $60 Xteink X4 looked like a great choice. And then I learned it had an ESP32 in it!

So I get it, start using it as intended. It's neat! I like the very focussed use case it presents. I think it might be too small for me as a regular ereader. But then I distracted myself from it's original use and started hacking on it. Turns out you can treat it like any other ESP32 dev board. For the record, it's an ESP32-C3 board with 16 MB of flash. Pretty low-end as far as ESP32 devies go. It doesn't have native USB support, just USB serial, but it does have a RISC-V processor and WiFi and Bluetooth.

And then I discover Crosspoint Reader, an entirely open source firmware for the Xteink, written from the ground up. Essentially written in Arduino using platformio, it uses the open source "open-x4-sdk" library to access the various peripherals of the reader in a nice clean way. Crosspoint offers some really neat features like saving your reading position, epubs with images, nicer fonts, WiFi book upload, and over-the-air (OTA) firmware updates. New features are being added all the time so don't wait for a release, just install from github.

And then on top of that, I learn that last month friend-of-the-show Liz, aka BlitzCityDIY, has also been hacking on the X4 and has added a CircuitPython build for it! And she made a nice helper library for it. While the CircuitPython firmware sets up the ePaper display to act as a standard CircuitPython displayio display, the helper library gives you easy access to the battery monitor and buttons (which are implemented as a resistor ladder, so kinda tricky to read). Thanks Liz!

Suffice it to say, there are ton of fun hacking opportunities to be had with this quite well-built little eink ereader. It's sturdy enough to live in my backpack and the fact it can act as an ESP32 WiFi devboard when I need one, gives it double utility. Highly recommended if you want a fun thing to hack on. But as I've not used it much as an actual ebook reader, I can't speak much to that yet!

12:58 Project Aura (Paul #2)

We've covered a couple Air Quality monitors over the years, and Project Aura is another, with a small twist. Project Aura is running as a MakerWorld crowdfunding project where you pay $30 for the 3D model, which gets you the 3MF file, firmware, and STL. The bill of materials is also provided, and you have to buy the parts yourself, which are about $200.

The firmware uses Arduino and PlatformIO and LVGL for the graphics - it looks really impressive, check it out with links in the show notes. It even has a night mode.

It also features an integrated web dashboard with live stats, events, settings sync, and OTA firmware updates. Initial setup can be done as it will create a wifi hotspot and uses mDNS to connect to it. And of course, it’s Home Assistant capable and uses MQTT for communication. Lastly, it features a safe boot - it will automatically rollback to the last known good config after crashes, making it easy to use.

17:06 Baochip-1x open source microcontroller (Tod #3)

The Baochip-1x by Bunnie Huang is another microcontroller platform like the RP2040 or the ESP32, but unlike those chips, everything about the Baochip is open source. It's based on open source RISC-V cores and the entire design is open. The Baochip includes a main CPU running at 350 MHz, four smaller cores running at 700 MHz, and a complete suite of accelerators of cryptography and encryption. For memory, it's got 2 MB of RAM and built-in 4 MB of RRAM, which is like flash. And it has an MMU, so it could host real OSes! In size and cost, it's similar to a Raspberry Pi Pico, but it's also so very different.

Bunnie has taken the openness of the Baochip to the max: in addition to the design being open and the ROM bootloader being open, the chip itself is transparent to infrared light, so you can inspect it with a microscope that the silicon you receive is what was promised. It's like a physical checksum to guarantee that the chip's not got malware or comporomized encryption hardware in it.

Recently Bunnie has published a couple of posts on the CrowdSupply campaign page that goes deep into the design details of the chip, comparisons with other chips and designs. As someone who once thought they were going to be a VLSI designer, these posts are magical. I recommend anyone interested in chip design to read them, as they cover decades of CPU design in a few pages.

The Baochip has four BIO I/O co-processors, that are sort of equivalent to the very cool PIO I/O co-processors in the RP2040/RP2350. In a BIO analysis document, Bunnie describes that while the RP2040's PIOs are conceptually simple, they're really quite complex, comparable to older CISC-style processors in how much can be done with a single instruction. This makes PIO take up a lot of physical space on the chip, so Bunnie took a different approach with the BIO processors: make each one a tiny RISC-V processor running at 700 MHz with a few tricks to make them better for I/O tasks. Since the I/O processors are full RISC computers with much more program space than the 32 instructions of PIO, these BIO co-processors could do additional signal processing tasks.

Disclosure: I'm an aquaintance of Bunnie and have personally backed the Baochip crowdfunding campaign. I can't wait to get my hands on these devboards and play around with the Baochip. A fully open chip that's not patent encumbered is the future. We all talk about open source, but everything we base our open designs on ultimately runs on physical chips that are literal black boxes. Let's change that.

21:51 OpenCode (Paul #3)

OpenCode is a 100% open source AI coding agent licensed under the liberal MIT license. It's built for privacy and does not store any of your data. OpenCode comes with a number of free models you can use or you can connect it to most other AI providers, like Gemini, Claude, and GPT.

OpenCode is available in the terminal or there is an app for your desktop and the web.