Windows 95 (Sort Of) on a Disposable Vape

It is amazing that computing power that was unthinkable for an individual to even possess a few decades ago has now become small and inexpensive enough to be disposable. The downside of these advancements is that many such devices — with perfectly good electronic components inside — are actually disposed of. This is quite wasteful, and since many of these components contain toxic materials, there are numerous potential negative impacts to human health and the environment that can result from tossing slightly old electronics in the landfill.

Fortunately, there are a lot of members of the Hackster community, and other like-minded individuals, that save these devices from winding up in the trash. And it is not just a good deed that these people are doing — they also get lots of free parts and even complete devices that can be repurposed and given a new lease on life. Electronics hobbyist Jason Gin recently came across a particularly egregious case of perfectly good hardware that is designed to be tossed in the garbage — disposable vapes.

Where Gin lives, the Kraze HD7K disposable vape is quite popular, to the point that these devices frequently wind up by the side of the road. It is pretty well known that vape pens have substantial lithium-ion batteries onboard to heat and vaporize the liquid contained within them, so many people will grab them to snag some free rechargeable batteries. But that is only the tip of the iceberg. The Kraze HD7K model, for example, also has a color LCD display screen and a pretty powerful microcontroller to drive it.

As a first step in understanding what these vapes could be used for, Gin did an in-depth teardown of the hardware. After getting the case cracked open, a 13450-size lithium-ion pouch cell battery was found. There was also an 80 × 160 pixel LCD display, a Nations Technologies N32G031K8Q7-1 microcontroller with a 48MHz Arm Cortex-M0 processor, 64 kilobytes of internal flash, and 8 kilobytes of SRAM. A 1 megabyte SPI flash memory chip was also housed in the casing.

Next, Gin did some reverse engineering work, focusing especially on the display since that is a prominent feature of the device. After finding the SPI interface and checking some documentation, it was demonstrated that arbitrary text and graphics could be displayed simply by using the Adafruit Graphics Library.

There are definitely some worthwhile components to salvage, but Gin also wanted to know if the full device could be repurposed. As a step in that direction, the device firmware was dumped and analyzed. After some digging, Gin found what appeared to be RGB565-encoded images embedded within the firmware.

Swapping these out would be a fun way to start altering the vape pen, so Gin decided to modify the existing icons to give the user interface a Windows 95 theme. That may not be useful for someone like Gin who does not vape, but it is a conversation starter, if nothing else. The next logical step (for a hardware hacker, anyway) is to get Doom to run on the vape. Gin is looking for help with that, so if you think you are up to the task, check out the project write-up to brush up on the basics of the Kraze HD7K.