[IC] Soleil - A Beautiful Solar Powered Wireless TKL

[upas]

>> We would love your feedback about Soleil here <<



About the Soleil

The Soleil is a solar powered wireless TKL keyboard. Inspired by the solar powered nature of trees and plants, beautiful wooden accents are integrated into the design.

This keyboard started as an idea from Gondolindrim. He came to me with an idea to make a solar powered wireless keyboard, so that the keyboard would charge itself, thus needing external charging seldomly, if at all. He had already picked a TKL layout, done calculations to make sure a solar panel over the arrow cluster could sustain battery usage in sunlight, and had basically done all the hard work to ensure that this idea was worth pursuing.

With a layout and PCB in hand, I asked James (of AKB fame) to take a stab at making a case for this PCB. We decided together that due to the solar-environmental motivation of the project, wood needed to be integrated into this board, and James did the hard work of actually designing something that works well with the looser tolerances of wood.

The end result is Soleil - an absolutely stunning mixed-material wireless keyboard that can fully self-sustain with just the power of light.



Solar Caveats

The math and real world testing has shown that under average office lighting, the keyboard is&nbsp;just shy of full autonomy. This means that under the average office lighting, you probably will need to charge this keyboard at some point.

However, ambient light conditions will vary greatly. Homes have less light than offices, which have less light than outdoors. If your office happens to get a lot of sun, there’s a chance the keyboard will self sustain! But even if the charge from your ambient conditions can’t sustain usage entirely, the solar charger will still extend the battery life of the Soleil.

The Soleil has a 780 mAh battery and uses ZMK (and supports ZMK Studio). Given how Gondo designed the PCB to be power efficient, and the efficiencies driven by ZMK itself, the battery should last 10 months (usage dependent), without any solar power. With that in mind, even with a trickle of solar power, those 10 months should easily be extended to a year or even more.

Additionally, because the Soleil is designed to be solar powered, it&nbsp;requires a battery to be installed. This is different from most ZMK-powered boards, which will work just fine without a battery as long as they’re plugged in via USB. This is due to the solar harvesting system, which requires a battery to be plugged in at all times.

While it would run counter to the purpose of this keyboard, if IC results show that people want to use this without a battery, we can provide a wired PCB option.


Wood Caveats

Wood is a natural material that expands and contracts with humidity, temperature, and a bunch of other factors. The wood parts may not be perfectly flush with some of the other metal parts depending on current conditions. With that in mind, the keyboard is designed to work around this. The variance in wooden parts will not impact the usability or feel of the board. But if you’re expecting wood parts to be perfectly flush to the 0.1mm, you’re in for a bad time. That said, we do expect the wooden parts to have a good finish, without any deep scratches, chips, or gouges.



An example of the fitment variances expected with wooden parts



Why didn’t we use stabilized wood? The whole idea of this board is to lean into nature. Every single wood piece is going to be different, and we wanted to keep more of a natural finish on the wood as well. Stabilizing wood also adds to costs, and we want to keep this reasonably priced. To us, it’s acceptable to lean into and embrace the natural properties of the material and design around it, versus trying to fight against it.

[upas]

Aesthetics

A lot of care was put into the Soleil’s construction to make something that would fit well together, minimizing damage to the more fragile wooden parts, while still achieving our targeted aesthetic.



On the bottom of the keyboard, you see wooden fins sticking through the case. This was actually quite tricky to pull off, given the tolerances and thickness requirements of wood. To make the pieces less likely to break, the fins are actually two separate wood pieces.



On the back of the keyboard, you’ll see wood surrounding a metal piece featuring a USB cutout and SOLEIL engraving. To enable this feature, we strategically placed ledges to pair the metal USB piece to the wood so the wooden piece is effectively sandwiched to the back of the keyboard; all screws only thread into the metal piece.



On the interior of the keyboard, the battery cover is also made of wood, and provides a beautiful accent even inside the board. Again, screws hold the cover in place, but no threads go into the wood directly.




The only wooden piece that accepts screws is the TKL cluster piece, in order to mount the solar panel, which should not be removed after installation. This wooden piece is attached to the top case via screws, but those screws only thread into the top case.




On the two sides and front of the keyboard, we see a seam which then opens up into a wider, aesthetically pleasing seam opening, suggesting growth or bloom.

Overall, the aesthetic of the board is not just beautiful, but a lot of care was put into its construction to ensure longevity and ease of build.




Layout Support

The PCB is hotswap and supports full/split backspace, full/stepped caps, split r shift, and both 6.25u and 7u bottom row. Sorry, ISO is not included, and unfortunately, we aren’t planning on adding it. The PCB and case are also designed for an F13 top row.




Mounting

For Soleil, we went with the tried and true top mount. It’s going to have all the characteristic sounds and feels of a top mount TKL keyboard. The plate looks like a classic top mount plate, with extra acoustic cutouts close to the spacebar. There’s also a leaf shape, again, playing into the solar powered theme of the Soleil




Other Features

As a nearly self-sufficient solar powered keyboard, there is no easily accessible power switch to turn the keyboard off. You shouldn’t have to turn it off since the sun will power it! But - there is a power switch on the top of the PCB that is accessible through the plate if you do need to turn the keyboard off for some reason.

Furthermore, the PCB supports ZMK soft-off (that is, a “sleep mode” triggered through a key combination), so if you’re worried about accidental keypresses when traveling with the keyboard, soft-off will save power and help avoid accidental keypresses. Once you need to use the PCB again you hit a wake-up combination of keys and the keyboard is ready!


There is also an RGB status indicator positioned under the scroll lock key position. This is a small, but important feature. It indicates battery status and connection status&nbsp;through different light colors and blinking periods, so you can understand how the keyboard is operating at all times.



Statistics

While this is an aluminum-based keyboard, we didn’t want the keyboard to be too heavy. It is wireless in the end, and if someone wants to carry it from home to work and back, we didn’t want that to be too difficult. As such, the weight reflects this.

Unbuilt Weight: About 1170g (2.6 lbs)

Fully built weight (Alu plate, GMK caps): About 1900g (4.2 lbs)

Typing Angle: 8°

Front height: 20mm (~24mm to spacebar)

[upas]

Colors and Wood



Right now, we have two colorways planned and set (these will definitely run):

Black and Walnut
E-White and Maple

We’re thinking about also working in a forest green colored aluminum case, but that could pair well with both walnut and maple. If you’re interested in something like this, let us know in the IC form!

Both the maple and walnut wood are sourced from the USA, but made in China. Surprisingly, even with tariffs, and shipping back and forth, it’s still cheaper to get these wooden pieces made in China compared to the price if they were made in the USA.

We are considering some other options though. In the past, we’ve collaborated with functional.co to create some amazing wooden keyboards. He has been kind enough to make some wooden pieces for us out of Pacific Northwest figured maple and Purpleheart wood.

Unfortunately, I don't yet have photos of these wooden pieces - but early next week, you can expect this IC to be updated with photos of them!

We would love to offer a version of Soleil with wooden parts made wholly in the US out of these parts - but we would also love to hear from you! What colors do you think they pair best with? Would you pay a premium price for these American-made wooden parts?

We’re also thinking about getting the aluminum parts also made in the USA. They’ll be quite a bit more expensive than the ones made by Hongtu. How much of a premium would you pay?

>> We would love your feedback about Soleil here <<



Pricing

We’re aiming for a price of $450 or less for this board. This includes wireless PCB, solar panel, 5 wooden pieces, 2 aluminum pieces, a plate and all the usual trimmings. If the interest check shows a lot of interest - maybe we can price at a higher MOQ and bring the price down!



While this keyboard doesn’t have any brass, the wireless functionality, battery, solar panel, and wood parts all add extra costs compared to a normal fully aluminum board.

Prebuilts






We think that Soleil might also make a great gift - and if you don’t want to build your own, we’re thinking about offering build services or pre-built Soleils. The price would go up, but we would likely offer some sort of discount to people who choose to build with us. Would you be interested in this? Let us know in the feedback form!

>> We would love your feedback about Soleil here <<


Next Steps
Sadly, the battery cavity on the prototype units is a bit too shallow for the production 780 mAh batteries, so we are waiting on getting some replacement, smaller batteries specifically for these prototype units before sending these units out to content creators.

We've already adjusted the case, and verified that the production 780 mAh batteries will fit with our revisions.

The PCB has been developed and tested - I even measured current running from the PCB into the battery in order to ensure that the solar panel and harvesting chip were indeed charging the battery. The firmware is done, and already runs on ZMK Studio.

We're aiming for a Fall 2025 launch for a Soleil group buy.


Thanks


For this keyboard, I really only helped facilitate, shared my opinions, helped write the firmware, and tested things.

I gotta give a ton of thanks to Gondolindrim for coming up with this idea and developing the PCB, and James for actually designing the board. As well as the CannonKeys team for their help in getting all the beautiful real photos you see in this IC.




>> We would love your feedback about Soleil here <<

[upas]

TL;DR for those in a hurry:

First, please look at the pictures.

Next:
- Solar powered, almost (but not quite) self sustaining in normal office lighting
- Wireless BT, ZMK powered with ZMK Studio
- 10 months of battery life without any solar
- Solar power will make it last longer if you don't work in a dungeon
- Colors are E-White and Maple or Black and Walnut
- WK and WKL will be available, F13 TKL, no ISO
- Top mount
- $450 or less, priced at 100 MOQ
- Considering price breaks at higher MOQs depending on how many people respond to IC
- Considering made in USA version for even more $$
- Gondolindrim, James (AKB) and I worked on this
- Aiming for a Fall 2025 Group buy


TL;DR for Simon:
Sun go brrrrrrr

[upas]

I had to split the post to get it to fit - apologies!

Reserved

[HubertThemad]

TL;DR for Simon:
Sun go brrrrrrr

  ) $5 says he won't see this at first and complain about the length. GLWIC Upas, this is a fantastic line-up (you, Gondo, AKB James) and I'm definitely interested in it!