next-hack.com has modified a USB Bluetooth Low Energy dongle (featuring an nRF52840, which is a 64 MHz Cortex M4, with 256kB RAM and 1MB flash) by adding a QSPI memory, a display, some glue logic (74HC74, 2 diodes and a resistor to create an “AND” gate), and a 3.3V linear regulator.
Because of the nRF52840 package, only those I/O signals that were actually used in the design could be easily accessible. The other one are on the bottom side of the package, and they are not exposed once soldered to the PCB. The design used 8 I/O pin, that’s whythey added some glue logic (we needed 10).
Doom runs extremely fast (typically above 30 fps). Much faster than 2019 Nordic’s port to the same MCU (running at 3-5 fps), and about as fast (and some times even faster!) than Nordic’s port to the nRF5340 (dual core Cortex M33, 512 kB RAM, the main core is clocked at 128 MHz). This project is about 80486-66 speed!
The display resolution is 240 x 240 pixel.
Tested with the following WADS:
– Shareware Doom (1.9)
– Full commercial Doom (1.9)
– The Ultimate Doom
– Doom 2.
The port has been tested on the following devices:
– The dongle shown in the video
– Adafruit CLUE board!
Note: any other device with the same MCU (devboards or even commercial product, provided that at lest 8 I/O signals are accessible) can run Doom using the code, with only minor changes on the main.h file! Programming was done with Segger Embedded Studio (for the projects) and Code::Blocks for the CLI-wad converter.
More information
- Article on next-hack website
- GitHub repo
- Doom benchmark website
- Dongle Aliexpress store <$10 US
- Adafruit CLUE board: https://www.adafruit.com/product/4500
See the video below for results with the dongle
