Xteink X4 with Open Source Firmware

 If you follow me over on Mastodon you'll no doubt have seen I have a new favourite device! The Xteink X4 is a tiny eink ereader which is pretty affordable, and definitely very pocketable. At around £44 from Aliexpress I took the plunge. 

One big plus that I had read about was that there are actively developed open source firmwares available for this device, most notably Crosspoint Reader. The supplied firmwares are pretty naff and also mine and most of these come out of the box setup with Chinese localisation. So to be honest, beyond just booting the device to check it worked I immediately flashed Crosspoint reader onto it within seconds. Flashing Crosspoint Reader is incredibly simple as there is a web flashing tool. Simply USB your device to your computer, point a chrome based browser at this website and click flash! Simple. 

 

 

After flashing Crosspoint I needed to add some epubs to read. I have a collection of stuff I've bought from HumbleBundle and usually used the PDF download so it was nice to see that they are all in my library available as epub files as well. The supplied SD card was pretty useless on my unit and contained a few spurious .bin files I couldn't quite decipher so I chucked in a better quality branded SD card. Of course you can simply copy and paste Epubs onto an SD card with the SD card connected to your computer, and in many ways thats the simplest and robustest method. 

 

However Crosspoint has a couple of other options. You can set the Xteink X4 up as a hotspot, connect to it via your computer or phone WiFi menu and then it will serve a small website with a file browser and transfer options. Similarly you can also connect the Xteink X4 directly to a WiFi network and then browse to your device from another device on the same network. Lot's of options.  

 

 

 

Speaking of options. there are also other ways you can create Epub to read on the device. There's an excellent browser plugin "send-to-x4" which acts to snip webpages and export them either to computer storage or directly to a connected Xteink X4 as epub. It's kind of cool to grab a long form article of pages like Hackaday and take them in my pocket to read offline. The other really useful one for me is that Libreoffice Writer which I use every day for work can  directly export epub files. This means I can take an article I am writing and want to read a draft of, or simply write myself a to do list or some notes which I can chuck on the device. 

 

 

So yes, it's primarily an epub device. No native support for PDF or other extravagant formats. However there is an Xteink format XTC which people sometimes use for graphic heavy books (Manga comics et al). There are some online convertors and a lovely SOURCE magazine reader (and donator!) asked if XTC might be a good format for SOURCE magazine on the device. Whilst it works... let me tell you... it's too small a device for the graphic heavy SOURCE magazine to work well on as a reading experience! 

 

Aside from books and documents, there's an ace feature in the Crosspoint reader firmware that allows you to set a single custom sleep image, or a folder with a gallery of randomly picked sleep images. I knocked up this super quick little name badge bmp image in Inkscape and GIMP and now my Xteink can double up as a lanyard mount name badge! Perfect.  

There are numerous official cased for the device, but I found the nice lanyard case on one of the many printables/thingiverse type websites.  But I really like reading on the device without a case, so I ended up making a custom version of a parametric FreeCAD Rugged box project and lasercut some different thicknesses of foam to make it the correct fit where it doesn't move in the case, but isn't likely to crush the screen. 

 

So my final thoughts on it are, it's cool, I love it, even in the little rugged case its incredibly pocketable and I am actively reading more having it in my life. It reads well outdoors and indoors and whilst not backlit its perfect for bedtime reading and gets me away from my distracting smart phone!  

SOURCE Issue 4 and the Future!

 

Way later than I ever wanted too, last week I published SOURCE issue 4. It’s got three tutorials, one on GNU Radio where we step through building an FM radio receiver using a perilously cheap Realtek SDR dongle, it has a walk through orientation tutorial for NASA’s Open Vehicle Sketch Pad (OpenVSP) which is a really powerful open source tool for designing and testing things that fly. It’s rounded out with a small tutorial on reverse engineering mesh files in FreeCAD using an up and coming community workbench called Detessellate.

The other thing people may have noticed since issue 3 of SOURCE is that it now has it’s own super minimal website. This is totally down to a lovely local to me chap, Luke Farrar, who quickly threw his amazing skills at setting it up. It’s served from Github pages an auto-generates the page when I push a new issue in the repository. It’s really lovely, and it is a great solution for SOURCE.

When I first started SOURCE I publicly committed to doing 4 issues and obviously that leaves the question now that 4 are done, what next? Well. I am going to continue, I enjoy the community responses and I’ve had a few people contact me about how it’s been useful. In the last week a lovely blogpost on the GNU Radio News site appeared being really supportive of SOURCE and, brilliantly, someone on Mastodon told me that because of SOURCE issue 3 they were planning to register a hardware design with OSHWA. These are the outcomes I dig very much. I’ve also had a small amount of donations. This is definitely not the main driver (In each issue I say that if you can’t donate then you are welcome to SOURCE and much solidarity to you) but it’s nice to see people moved to support.

So yep. I have some plans for ISSUE 5! Hopefully a few bits of content that are totally different to what's come before, but also, some solid tutorial content supporting brilliant open source projects.

Repairing an Interesting E-Bike for Beics Ogwen

 It's Sunday morning and later I'm off to volunteer at my local repair cafe, reminded that I never wrote up this little repair story! A few years ago I used to volunteer every Friday for Beics Ogwen a local Beic hire/workshop/education project. Times changed and for various reasons the volunteering aspect of it stopped. 

Recently I've taken on a new office near Beics Ogwen and my mate Morgs is running the project. We were chatting over a brew and looking at the invariable collection of stuff a project like that accrues, when I spotted an older ebike in a partial state of neglect. 

 

It caught my eye as it had some interesting parts on it and is a wild looking step through frame. It has a Nexus 7 speed hub on the back and the hub motor is in the front wheel. It's 36V and generally looked in good order. Morg explained that the battery refused to take a charge and additionally... the key to remove the battery from the rear rack frame was missing.  

I was pretty sure that the battery was too flat to take a charge. The Battery Management Systems (BMS) in e-bikes have rules and one rule is that if cells in the battery go below a safe discharge threshold (often around 2.5V per cell) then the BMS will refuse to allow the potentially damaged battery to charge.  

 Whilst discharging a cell to below 2.5V can cause damage to the cell, often, and particularly in my humble opinion if the cell has just been sat in a reasonable environment for a few years discharging very slowly, often there is little damage and they can be revived.  But... the battery needed to be stripped...

 

I LOVE LOCKSPORT and it's not a crime! So yes I broke out the lockpick set and made short work of the lock on the battery compartment of the rack. For those in the know I approached this with a very thick tension wrench and a ball pick. It picked so easily I then relocked it and picked it with a simple Bogota rake. These locks are definitely a deterrent and not hugely complex or secure. 

 

With the battery out of the frame I took it to my workbench and removed the casing. This meant I could then multimeter across all the individual cells. They were all incredibly flat! There are two options to begin to revive the cells. Basically both options are to charge the cells with a constant current limit set to a very low amount. The better but slower way is to supply 100mA to each individual cell aiming for say 3V, but you can also sometimes, if all the cells are behaving, supply the whole battery system with a constant current to bring the whole collection of cells to over 25V. Both these options are dangerous... don't do this if you don't know what you are doing! You definitely need to be constantly giving the system your attention, checking for any significant changes in temperature and appearance and also be ready to sling it all in a metal bucket and exit the building quickly should any magic smoke begin to appear.  

 

A couple of hours later and the cells had been warmed through and the whole pack was sat at around 29V. This meant that the BMS would allow the battery to charge from the charger once more. A quick reassembly of the pack and then a long charge cycle ensued with the battery charging to full in around 7 hours but then taking a further 5 hours to balance the cells. It should be quicker to charge on subsequent charges. 

 

Putting the battery back in the frame I was delighted that the system came to life, some air in the tyres, a tweak of the gear cable and it was ready. I took it for a few test rides and, with some big caveats, it's riding as it should! It's fair to say that this bike is great on the flat, zippy even! However both the older design of assist, the very sit up and beg riding position and the Nexus gearing makes this bike very undergeared for hills! It's deffo not that useful for riding the sides of the Ogwen valley! However, it would ABSOLUTELY suit someone who lives somewhere with a flatish route they do regularly, or, if someone is living on a narrowboat and does a lot of towpath riding, it would be perfect! Whatever it's future, I'm glad I got it serviceable again. If you might be interested in this bike it's for sale at Beics Ogwen, hit them up with an offer!  

 

 

FOSDEM 2026 photodump!

Little random photodump from FOSDEM 2026. For future me this is the one where I first volunteered as a Devroom manager co managing the Open Hardware CAD/CAM devroom with C Hennes. 

Our final talk was a love letter to the KiCad ERC... ace!

Yorik giving a great FreeCAD status update. 

Was really pleased to get more actual hardware stories on the stage, rather than all software for hardware stories. Arya and Lina.py gave a great presentation 

Ryan and his Blackpants story about making a flipper zero addon hat and then actually making an entire improved version of a flipper zero to run the hat!

 

Devroom Diva! 

 

 

 

My Four Thieves Vinegar Collective mascot came with me on the trip. 

FOSDEM AV team hardware. What legends. 

The elixir of eternal geek. 

 Super proud to have facilitated Manu bringing the Micro Manipulator project.

 

Libreoffice swag

Kosova peoples!

Forged in FreeCAD and KiCad stuff... Tanmatsu above and 1/1000th stonehenge below

 

 

Friets!

FreeCAD day compadres. 

Swag!

Brussels and awesome persian grub

Delirium... home of bad decisions

Dogtag. 

 

Kosovo trip 2025! Photodump and thoughts!

A while ago I got back from this amazing second visit to Kosovo. I first went out to Kosovo to speak at the Software Freedom Kosovo conference in 2019 when I was working for Libre Space Foundation. It’s been lovely to stay in touch with the team there, help out organise this years conference, and then attend and do a few talks, lectures and workshops. Of course it's also very fun to socialise and hang with a global cross section of the open source culture scene.

The SFK conference was held over 2 days, but I don’t like to travel/fly without maximising my usefulness these days so we extended my program with some days giving lectures and visiting local tech companies. I gave a general lecture about my work and opensource at FIEK to a group of ICT undergraduates, I gave more specific lectures on designing for opensource and OSHWA certification to UBT Mechatronics undergraduates as well as a similar lecture to some Masters students in Computer Sciences.

Over the conference I gave a long workshop each day with Saturday being an “Introduction to FreeCAD for CAD beginners” and on the Sunday a run through “Designing a PCB for fabrication with KiCad.” Also on the Sunday I gave a keynote address “Outside the Locked Box, Why opensource IS innovation”. 

 

Between all of this I got to hang with brilliant friends old and new. Lis and the crew at Prishtina hackerspace know not only how to do hospitality, but also how to brew amazing beers and distil amazing raki. Conversation flows, in Kosovo you are never far away from a friendly but passionate talk about politics and history. I made some amazing new friends and contacts whilst here. In particular a couple of young volunteers at the Hackerspace, Jona and Jora who were so great to hang out with. 

As I write this my attention is slightly pulled to the next conference, FOSDEM, on which I am doing a little voluntary work as a dev room manager, but I look forward to picking up with the FSK team as and when to support next years conference. Oh and if you are into opensource or open culture… get out to Kosovo for this. It’s a fabulous event.