I messaged you on Discord.

Edit: I messaged all 4 of you on Discord.
After some testing yesterday, even with the backlight off, the battery on my KE went from full (4 bars) to 1 bar in about 6 hours. So an extended battery would be great, especially if you want to use this as a kind of mini portable computer/PDA.

There is a large empty space in the right-hand side of the case, which would be perfect to house a battery. The space is also used to store the slack in the wiring, so an added battery can't take up all of the space. I have ordered a replacement battery for the Samsung Galaxy S5, which seems to be the right size. That will be delivered today, and I will try to test it tonight.

Tomorrow, I have surgery on my hand. There was an incident last week where I cut my palm/finger pretty badly, and the surgery tomorrow should fix what the ER docs couldn't quickly fix last week. So, there may be a slight delay in the delivery of the kits as it's hard to dye-sub keys with one hand haha.
Oh man, I hope the surgery goes well! Don't be in any rush to get this done with only one hand. Having two hands is slightly more important than calculators!

What the capacity of S5 battery did you choose? I saw a range of 3300mAh to 3800mAh. Assuming it's the latter, that should give a nice bump to battery life to 22-24 hours if my napkin math is right. That's about how long my old TI-84 Plus CE lasts which is definitely acceptable.
Surely I can just plug in an external power supply? Razz Who needs batteries when I don't plan to move it lol.
My hand surgery went really well, recovering now and will be in a splint for a while. I got a nerve and a tendon reattached in my middle finger.

I also tried out some options for adding an extra battery. The replacement battery for the Galaxy S5 fit really well in the corner. I got one of the higher-capacity ones, around 3750mAh. Haven't tested the battery life yet, but the added weight makes it feel substantial. There is a 7800mAh version, but it is twice as thick, so it doesn't fit in the case.
Glad to hear those precious hands are on the mend. An additional battery would be great - but I think I'm going to be more like Mateo Smile.

Could put in one of those solar strips just for giggles Very Happy.
If you decide on doing another run I would absolutely love to get one Very Happy
I really want to flex on my classmates with a mechanical ti-84
I would love to have one of these.
If you're in the mood to build another one, let me know.
I will happily pay for it all + assembly.
Hand is doing very well at this point, getting the splint removed/downsized in 3 days.

By adding the Galaxy S5 battery in parallel, the battery life of the KE is amazing! Instructions for installing a second battery will be included in the assembly manual.

For the 4 of you who are patiently waiting for your kits, they are coming soon. With only one working hand, I can't print keycaps, so the delay right now is a physiological one. Sorry!


Welcome ProfoundMagician and Eulers (nice username!). There seems to be a growing interest in more of these kits. Along with my burning desire to add addressable RGB, a Version 2.0 is in the works!

I will continue this tread as I develop version 2, so keep an eye out for updates.


What features should I add for Version 2.0? If you have any thoughts or suggestions, I'm all ears!
I need one of these as a fellow engineering student! I thock so hard in class. If i could have any input i like your second rendered case in the original message.
Hey man! I am also an electrical engineering student and this looks like a fun pcb project to build with for sure! I am interested in purchasing one if you release the link to order a kit. Until then keep up the good work!
This project looks really cool. I'd love to purchase a kit!
I would love to buy a kit
Saw the post about this on Reddit and had to come say I'd also love to get in on a second round.

As for v2 improvements, hotswappable switch sockets could be really cool. If this already has those then I missed that skimming the thread tho Razz
i would absolutely buy one of these if you were to make another kit! a cool v2 improvement you could make would be a cover to protect it in a backpack.
I literally made an account for this website just to say I would love to buy a kit for this. As someone mentioned in a comment above, it would be cool if the switches were hot swappable for v2
ZXSwire3 wrote:
I literally made an account for this website just to say I would love to buy a kit for this. As someone mentioned in a comment above, it would be cool if the switches were hot swappable for v2
A cool little thing to add if you have the free time would be a fancy on/off button if there is space.
If no compromise to space, some cool on and off buttons would be (IMO):

an arcade button (Lots of space needed)
A cool little switch (like a light switch or a metal rod switch similar in function)

those are just 2 ideas off the top of my head, but I'm sure that you or others would have even better more creative ideas.
ZXSwire3 wrote:
I literally made an account for this website just to say I would love to buy a kit for this.

Same Laughing
ZXSwire3 wrote:
switches were hot swappable

This is definitely a good one
basilavenue wrote:
cover to protect it in a backpack.

This is something I would definitely want doesn't have to be fancy just a simple 3d printed piece would be really niece.
Thank you all for the feedback!

I understand that quite a few of you made an account here just for this thread. I highly encourage all of you to explore the site, dig your calculators out from the back of your desk drawers, and try some programing! There are plenty of guides on this site and others, and we Cemetechians are always available in the chat (left side of the website, or on Discord and IRC) to help out, answer questions, and give tips and tricks. Welcome to Cemetech!


Small update: I had my splint and stitches removed, so I am back into the production of the Version 1 kits. I'll post more pictures and updates and things progress. Mainly need to 3D print parts and do some pre-wiring. I sure hope you like the kits, and I'll make a comprehensive how-to guide, and will obviously be available via chat to help with assembly.


Version 2 development is underway! Here are some features that will be added:

Hotswap sockets
Per-key RGB backlighting
Adjustable angled feet


I will upload all of the files/CAD/software to my website (not sure if uploading non-programs to the Archive here is okay?), and will attempt to have Version 2 be able to be ordered through an online store (I have a friend that hosts their own commerce site, I will try asking them to add the KE V2 to their listings). I am thinking about selling V2 fully assembled, but the price would match. (Rough estimate would be $275 for a felly assembled KE V2, calculator included). What are your thoughts about that?

I am toying with the idea of making an Nspire CX II CAS Keyboard Edition, (TI Nspire KE CAS?), but I have a feeling boone would buy it (on top of being much more difficult to make), so it would just be a project for myself.
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