Wiring GPIO to arcade machine control panel

rasp_renegade

Hi folks, I have read many articles and check shopping options but I still am not sure of the best solution to go from the Pi to an arcade machine control panel.

I got the super cool ribbon (looks like the old IDE cable) to connect to the GPIO pins, then connecting to the bread board. The problem is, I need to convert the jumpers coming out of the breadboard from 26 AWG wires to at least 18 AWG. Splicing them together is how I did the last one, but there must be a better way.

Not to mention, it is no easy task to splice 26 AWG wires!!!

WeirdH

@rasp_renegade Is there a reason why you need to connect a control panel through GPIO? Because an easier way would be to get an encoder board to plug your buttons into. The encoder then plugs into a usb port on the Pi, super easy.

Lolonois

@rasp_renegade I assume you use something like this [1] on the Pi side. I would solder the AWG28 and AWG18 together and use shrinkwire to isolate, although it is a tedious task. I would avoid mechanical connections as they may loosen over time.

[1] https://docs.rs-online.com/b3c4/0900766b815462bc.pdf

jamrom2

@rasp_renegade

I second WeirdH. I use Ultimarc's boards on all my Arcade machine projects.

Cheap, very easy to install and no config needed.

Read about it here and read more to get familiar with thier family of products.

Save yourself a lot of time and headaches.

https://www.ultimarc.com/control-interfaces/i-pacs/

Folly

@rasp_renegade

If you really want to use the gpio pins it's better to use header wires such as these :
https://www.reddoko.com/uploads/45296/800x8001577687287.47135541.jpg

The are available in different lengths and different combinations (male-male, male-female,female-female)

rasp_renegade

@folly

I am not installing the pi that close to the control panel. They dont make these 3-6 ft long. There is sill the matter of connecting these to bare copper wire either way

Folly

@rasp_renegade

1 ft (30 cm) is usual.
Indeed, perhaps not an ideal solution for you after all.

You can also buy headers like these :
https://core-electronics.com.au/media/catalog/product/s/t/stackable_0.100_female_header_2x20_pin_straight__pololu_2748__00.jpg

You can solder your wires directly on the pins and use some heat-shrinkable tubing.
You can even bend the pins to make some room.

Just an idea, don't know if it suits your needs though.

Lolonois

@rasp_renegade said in Wiring GPIO to arcade machine control panel:

I am not installing the pi that close to the control panel. They dont make these 3-6 ft long.

With that wire length I would refrain from using GPIO directly!

Why is GPIO for longer wires not advisable? Mainly because the Rpi4 has weak internal pull up resistors (50-60 kOhm) and the long wires act like an antenna for stray and input capacitance. In short: You may get ghost inputs.

You can mitigate it by using external pull ups (at least 2k) next to the GPIO header and disable software wise the internal pull ups, but I guess you were asking for less effort, not for more effort. :)

Better place the beforementioned USB based solution or a MCP 23017 which uses I2C for transmission (much cheaper than the USB boards, can also be driven by the mk_arcarde_joystick module as you may know from your previous builds) close to the control panel. Then use USB / I2C for transmission on the longer distance. They both have more robustness/error detection. With 6ft you are far below the maximum cable length of USB2.0 respective I2C.

rasp_renegade

Thanks guys, this was very helpful. I just ordered the
I-PAC2. =)