Bluetooth HID Gamepad And HC-05 Serial Hack

“Which came first, the chicken or the egg?” Don’t bother us with stupid questions, they both co-evolved into the forms that we now serve up in tasty sandwiches or omelets, respectively. “Which came first, the HC-05 serial-flash-hack, or the wireless Bluetooth Gamepad?” Our guess is that [mitxela] wanted to play around with the dirt-cheap Bluetooth modules, and that building the wireless controller was an afterthought. But for that, it’s a well-done afterthought! (Video below the break.)

It all starts with the HC-05 Bluetooth module, which is meant to transfer serial data, but which can be converted into a general-purpose device costing ten times as much with a simple Flash ROM replacement. The usual way around this requires bit-banging over a parallel port, but hackers have worked out a way to do the same thing in bit-bang mode using a normal USB/Serial adapter. The first part of [mitxela]’s post describes this odyssey.

With his Bluetooth module now functioning as a gamepad, [mitxela] just needs a gamepad to play around with. After finding an exotic vintage SNES controller on eBay, he hot-airs the old logic off, adds magnet wires to the leads, tosses in an ATtiny2313 for good measure, and he’s done! It’s a beautiful controller, with custom firmware and a custom ROM in the Bluetooth. Beauty!

[mitxela] is no stranger to Hackaday: we’ve covered his tiny MIDI squarewave synths before. You should really go check out all the projects on his blog.

20 thoughts on “Bluetooth HID Gamepad And HC-05 Serial Hack

    1. Part number is DK-USB-SPI-10225-1A for anybody wondering. The difference is that the cheap interface only works at 3V and is only SPI. It doesn’t have a UART also unlike the expensive interface.

  1. Obviously the egg came first. Egg laying species predate chickens by millions, maybe billions, of years. Chickens were bred into existence by man, as were modern cows, and dogs.

    1. Yup. Chickens are birds. Which evolved from reptiles. Which lay eggs. Duh!

      The chicken’s natural ancestor apparently still scratches around the woods in China, where it originates, and looks like a more exotic version of a domesticated chicken.

    2. The chicken and egg dilemma can be solved either way depending of the point of view once you assume evolution as true.

      S: “A non-chicken lays an egg from where it hatches a chicken”
      Q: Whose is the egg from, that who lays it or who hatches from it?
      A: In the former case, first is the chicken, in the latter, first is the egg.

      Choosing one over the other says more about our biasses than about the birds. ;)

  2. This is all well and good, I’m actually really impressed by the final product, but I want the other side of this setup: I want a simple Bluetooth receiver that can connect to a gamepad or two and be used as input to the hardware I’m making.

    I’ve still not found a good solution for this, and the options I have found are really hacky. Unfortunately I don’t yet have the skills to make this happen myself(though I am working on a design or two).

    Think of the possibilities: custom game systems, control your robot arm, control a ROV or RC car, etc… All from any Bluetooth game pad.

      1. Yeah, but that’s using the stock HC-05 firmware. It can run as master, but only supports the serial profile, not HID. If I was building my own controller, this would be no problem as I could just use serial communications from the controller as well. But, the goal I have is to use a generic Bluetooth controller and HID to control my project.

          1. Nope, but if you do, let me know. Best I found was to connect a bluetooth dongle to a USB master shield on a arduino. The code supports HID devices on the USB side and the translation from bluetooth to USB is basically direct for HID. I never tried this, as it was more hardware then I wanted for my experiments.

  3. “they both co-evolved into the forms” 🤣 the chicken and the egg both co-evolved… So independently? But into a single biological organism? Is this really a theory? …thank you for making an argument that supports creationism so well. That’s absurd.

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