Hey guys, I finally got around to updating the PSX to DB15 code to fix a timing issue that prevented HORI controllers from working with the DB15 adapter. If you have one of my adapters you can download this firmware
hex file here and program it using a USBASP and AVRDUDESS. I'm hoping that a few people would be willing to update and test their collection of PS1 and PS2 controllers to help me make sure that this fix didn't break something else. If you would like to update please follow these directions below.
In order to program the adapter you will need to remove the 3D printed shell and bridge the jumper labeled J1. Then you will need to hook up the ISP pins from the DB15 connector following the pinout printed on the back of the PCB to the programming header of the USBASP.
In AVRDUDESS all you need to do is load the new hex file into the "Flash" field, hit "Detect" on the MCU field to load the correct MCU option for your board, and then make sure that all of the fuse settings match the image I have provided below. After all of that you can simply hit the program button and the new firmware will be installed.
So far I have tested the new firmware on all of the official Sony PS1 and PS2 controller models, the HORI Real Arcade Pro PS1 arcade stick, the Brook Retro Board, and the MC Cthulhu. All of these are working properly with the update, but some of the others on the compatibility list cannot be confirmed since I don't have those particular controllers on hand. Namely the SNK NEOGEO pad, and the Namco arcade stick.