An article in IEEE Spectrum titled “Novena: A Laptop With No Secrets,” which describes Bunnie Huang’s Novena open-source Linux laptop, stopped me in my tracks when I read “The most extraordinary step we took was to include a field-programmable gate array (FPGA), a type of processor chip that can be reconfigured by its user to change the chip’s specs and capabilities. Basically, this reconfigurability allows the chip to do things in hardware that would otherwise have to be done in software.”
Being a blogger who writes about FPGAs, I figured I’d better pay closer attention to this article, which continues:
“For instance, if you wanted to accurately control a dozen motors, you’d have a lot of trouble doing that in software. Motion control requires exquisite real-time control over waveforms, and if you try to get your operating system to do that it would constantly be shifting from one task to another and back again, adding too much timing jitter. Imagine that stutter you see in your Web browser but in a self-driving car or a drone: instant wreck. However, it’s a relatively simple matter to create hardware that runs the fussy timing and key control loops, and it’s also trivial to replicate variations of that hardware again and again in an FPGA.
And at one point, we did in fact want to control a lot of motors. We had the wacky notion of mounting Novena in a quadcopter chassis so that our laptop could hover and follow us around the office; we figured we’d use the FPGA to interface with the requisite motors and sensors. Consequently, the FPGA’s input-output connectors were originally targeted toward servos and motors.
Cooler heads eventually prevailed. We instead optimized the FPGA for data acquisition by adding a bank of local high-speed DDR3 RAM chips, a form of high-speed dynamic access memory. This upgrade allowed developers to implement a variety of expansion cards, including one for software-defined radio and another that worked as a digital sampler, which could allow engineers to use our laptop as a portable oscilloscope.”
However, the text of the article doesn’t name the FPGA. Too bad. But wait! There’s a pretty clear photo of the motherboard in the article, as shown in the above image. A close-up shot of this photo tells a more complete story:
It’s pretty clear that the FPGA is a Xilinx Spartan-6 device providing Huang’s Novena laptop with hardware-programmable goodness. Huang, a well-known open-source advocate and a very popular speaker on the EE event circuit, has created a Web site for the Novena open-source laptop with this detailed motherboard image:
Novena Open-Source Laptop Motherboard Detail
This high-res image shows that the FPGA is a Xilinx Spartan-6 LX9.
The Novena open-source laptop was a successful crowd-funded project on the Crowd Supply Web site. The project drew $783,329 or 313% of the targeted funding level.
Note: Xcell Daily covered the Novena Open-Source Laptop back in April, 2014 before it became a successful crowdfunding project.