Introducing the Retro Watch.  A passion project 10 years in the making.   In the end, all watches are jewelry so looking cool is goal #2...but being a legitimate, powerful, gaming system is really the goal of this project.

Machine metal, water resistant case,

Current all metal case size comparison

Hardware Assisted Rendering and Emulation

Besides its formfactor and custom high resolution display, the feature that really sets this platform apart is the inclusion of an FPGA to create custom video game hardware on the fly.  Utilizing custom rendering cores,  the "hard parts" of accurate emulation (tricky video and sound timing) can be offloaded from the main CPU, allowing most 8 and 16 bit systems to be emulated with unmatched accuracy and perfect lag free speed.

Gaming

With am Arm Cortex M33 running at up to 160MHZ + 2 low power cores for Bluetooth and sensors, 1.5MB of fast ram, 8MB of external ram, a dedicated low power 2D graphics processor (and an FPGA we can turn on for heavy gaming) this watch is a lot more than just a watch.  It will easily handle just about any DOS era game and has more horse power than the Nintendo64 era systems.
 

Connectivity

Connect to any smart phone to send and receive messages, interact with applications, and download new apps, games, and updates.

Oh...and its a watch...

It tells time...for a really long time between charges if you don't play games on it ;)
 

The origin story

So, what is the Retro Watch origin story?  Well...it all began about a decade ago...

I was on a one year sabbatical from the Navy studying for my Electrical Engineering masters degree at Stanford.  The time away from driving Nuclear Submarines felt a lot like being on vacation and for the first time in a long time I had some time for some serious hobby work!

Game programming and video game hardware have always been deeply fascinating to me so I took every opportunity to combine my studies with this passion when I could get away with it.  Taking a course in cpu design, I got my first real taste of Field Programmable Gate Arrays (FPGAs).  Having written a few software emulators the control over timing and parallel operations was eye opening and a whole new world of system emulation seemed possible.

At the time, I was hanging around an IRC hardware hacking channel and was acquaintanced with a man developing FPGA code that would emulate an original Nintendo Entertainment System (this work later became the Analogue line of FPGA based consoles). I became enamored with the idea of doing my own Video Console implementation on an FPGA.

My first project took me a minute but the result was pretty cool:

A cycle accurate video game console implementation running on an FPGA development board.  It was impressive enough that it was noticed by Terasic (the makers of the development boards I was using at the time) and I was gifted one of 10 newly released development boards in exchange for my project being featured upon its release.  Pretty cool right!?  

Enter Efinix, Inc.  It turns out they make a really tiny FPGA with enough logic and a low enough power draw that it just might work.  So I reached out.  They were immediately enamored by the concept and set me up a dedicated sales channel like I was going to be buying millions of them!  Seriously, best sales experience I've had for components and they gave me way more attention than my likely purchase quantity warranted. So I ambitiously sat down and worked out the schematic and layout for my first prototype....several months (and several thousand dollars) later it arrived for testing.

Power analysis showed we would get 2-4 hours of battery life from a 300mAh battery when the fpga is fully engaged and running a video core with 2D gaming power to match the best 16 bit consoles of the 90s.  Not bad AT ALL! And if you keep in mind the watch, when its just being a regular old smart watch, only eats about 3% of that we should easily get 4 days of battery life.    We were in business! (actual battery capacity and battery life metrics will change as the design matures)

Efinix even allowed me to register the watch as an official development kit for their FPGAs which means all Retro Watches will also be full fledged Efinix FPGA development kits.

 So..fast forward a few years after a lot of breaks for real life (Navy, work, kids, finances, etc...) and a few prototypes (a few more thousand dollars) later I finally got to a design I thought just might work.
 
An evolution of cases...




The first concepts...

 The first fully functional prototype.  Looked really slick but it was just so big on the wrist :(

While we are still refining our case has come a long way!  This is the most likely final form factor:
 

Cases were not the only thing we iterated through...we are on our 4th PCB revision!

Finally, lets get to some of the technical details:

The main processor: Renesas / Dialog DA14706 with 1.5MB of internal ram, 8MB of external QSPI Ram,  ARM-M33 application processor at a scalable speed of 32Khz to 160Mhz, dual ARM M0 processors for handling sensors and BLE, 2D GPU that supports most bit blit operations.  3 high speed Flash/ram qspi interfaces for fpga interconnect, memory mapped psram, and flash.  This CPU was made for this!

Efinix T20 FPGA with ~20Kb logic elements and ~1000Kb of ram...more than enough to match any 16 bit console in the 90s and maybe even push us to the first 3D generation.

Peripherals: Magnetometer, accelerometer, audio amplifier + speaker (mono), notification buzzer or vibration motor, light sensor, our display isn't finalized but it will be a minimum of 60Hz 320x320 pixel LCD for gaming and will convert from watch form factor to game form factor on or off the wrist!  4 action buttons + dpad

So...where are we in this process?

We have a miniaturized proof of concept capable of doing most of the normal smart watch things as well as being a monster video game machine that will rival anything from the DOS and 16 bit console area....and allow for cycle accurate hardware assisted emulation of existing older systems!

Feasibility is complete.  We have built it, it works.

Case design is well underway with some final tweaking needed based on where we settle on screen technology.

Here are some demos running on the previous and current hardware revisions.  Everything is running on the board with the USB breakout merely providing debug access and power. 

A very slow frame buffer ray-cast demo:

Some very simple proof of concept video game emulation I wrote in an afternoon...

While this watch will certainly have the power to emulate most 8 and 16 bit era systems, its meant to run custom games.  It is a watch after all, and emulation takes close to 10x the processing power (and 10x more battery) over a similar game running natively on the hardware.

One of our primary goals is to make the system as development friendly as possible with every watch capable of acting as a development kit, well documented programming APIs with lots of examples and tutorials, and well maintained tools to support game development.   Will there be a curated store of some sort to host games and applications? We have plans!  

Some early demos showing off the power of our prototypes:
Test Setup:

Doom!  Yes, you can play it with a BLE wireless controller!

Pico8 Emulation!

Test setup:

  

Risks and challenges

The biggest Risk to delivery (in order): Case Mechanical. We got a big head start on this part of the project thanks to some great help (on credit) from a watch making guru.  Fully milled metal cases are already in hand and we are close to having the final design ready to fab.  Manufacturing path is secured, rough quotes are in, just some final hardware selection bits to work through.

Mitigation: We hired the best smart watch case engineer on the planet and he is doing amazing things!  I think we are going to nail this one and way ahead of schedule.  

Software stack. A full featured software stack for a Smart Watch is not trivial. Nor is the dedicated IOS and Android apps that will need to accompany them. A lot of work is in progress on the UI flow and maintaining that classic retro look.

Mitigation: We are spending money on some great pixel artists and already have a small development community contributing to the cause.  Stay tuned for more UI updates as the mock ups roll in!

PCB Finalization: While the vast majority of the work has been done to validate the current design there is a cost down, mechanical fit, and miniaturization step that will take some effort. This iterative refinement is already underway with the lower control deck pcb about to go to fab  followed shortly by what we hope is the final "big" development board to wrap up screen technology testing.  Since we have already miniaturized twice, the upper pcb actually isnt that daunting and should come together pretty quick.