# Building a Button Box for Star Citizen (space game) **URL:** \ **Category:** Product Design\ **Created:** [December 16, 2024, 11:47pm UTC](https://forum.arduino.cc/t/building-a-button-box-for-star-citizen-space-game/1332881 "2024-12-16T23:47:49Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![seriphai](https://avatars.discourse-cdn.com/v4/letter/s/edb3f5/32.png) [@seriphai](https://forum.arduino.cc/u/seriphai)\ **Post date:** [December 16, 2024, 11:47pm UTC](https://forum.arduino.cc/t/building-a-button-box-for-star-citizen-space-game/1332881/1 "2024-12-16T23:47:49Z")
Hello all, I am trying to build a button box using PCF8575 IO expanders and I am seeing a bunch of confusing posts all with different opinions on how to wire them and code them. ## Hardware I am planning on using: [Buttons](https://www.amazon.com/gp/product/B08L13JG8M/ref=ox_sc_act_title_1?smid=AUTFQ43Q7FMBM&psc=1) [PCF8575](https://www.amazon.com/gp/product/B0B82L2ZCQ/ref=ox_sc_act_title_2?smid=AGTXEOAZWIVDD&psc=1) [Switches](https://www.amazon.com/gp/product/B09W5FP2RM/ref=ox_sc_act_title_3?smid=A1MYENKL68XMV9&psc=1) [controllers](https://www.amazon.com/gp/product/B0D83FBYPD/ref=ox_sc_act_title_4?smid=A1NOQTMMT39TJ0&psc=1) This is the wiring diagram ive worked up. I am not an electrical guy, I am a software guy by trade. But Ive recently seen something about needing to add a resistor between the controller and the SDA and SCL pins? Any advise you could give me here would be valuable. ![image](https://europe1.discourse-cdn.com/arduino/original/4X/c/d/e/cded41b0d6e00657064d9cbacadebd3bab64bc44.jpeg) ## Project Description: I am using 7x ON-ON SPDT switches, that is the Orange dots representing the 2 pins per switch for inputs. I am using 18 LED momentary Push buttons. Button inputs are blue, LEDs that wont be lit up by power supplied to the buttons are represented in Green. 3 of those buttons I want to always be lit, the other 15 buttons are sorted into four Button Group that I only want to be lit up when certain conditions are met: ie IF(PF8575\_one.pin10 == HIGH) then (controller.pin10 == HIGH) I am unsure where 5v is on the controller, so the power is not connected there until i purchase everything and get readouts. Same for the Interrupt, which im not sure how to use anyway. Anyways, any advise or alterations you think should be made, I would love to hear them. Pic of projected final project below: ![image](https://europe1.discourse-cdn.com/arduino/original/4X/b/0/3/b036ab6eecbf64efa5ff47d3528d91a0e9b62ea2.png) ---
**Author:** ![LarryD](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/larryd/32/215550_2.png) [@LarryD](https://forum.arduino.cc/u/LarryD)\ **Post date:** [December 17, 2024, 12:16am UTC](https://forum.arduino.cc/t/building-a-button-box-for-star-citizen-space-game/1332881/2 "2024-12-17T00:16:14Z")
- Read Nick Gammons discussion here. > **[Gammon Forum : Electronics : Microprocessors : Using a keypad matrix](https://www.gammon.com.au/forum/?id=14175)** > > Gammon Forum : Electronics : Microprocessors : Using a keypad matrix ---
**Author:** ![seriphai](https://avatars.discourse-cdn.com/v4/letter/s/edb3f5/32.png) [@seriphai](https://forum.arduino.cc/u/seriphai)\ **Post date:** [December 17, 2024, 12:20am UTC](https://forum.arduino.cc/t/building-a-button-box-for-star-citizen-space-game/1332881/3 "2024-12-17T00:20:52Z")
I am intending to use the PCF8575 library and Arduino Joystick libraries > **[GitHub - MHeironimus/ArduinoJoystickLibrary: An Arduino library that adds one or more joysticks...](https://github.com/MHeironimus/ArduinoJoystickLibrary)** > > An Arduino library that adds one or more joysticks to the list of HID devices an Arduino Leonardo or Arduino Micro can support. > **[GitHub - RobTillaart/PCF8575: Arduino library for PCF8575 - 16 channel I2C IO...](https://github.com/RobTillaart/PCF8575/tree/master)** > > master ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [June 15, 2025, 12:21am UTC](https://forum.arduino.cc/t/building-a-button-box-for-star-citizen-space-game/1332881/4 "2025-06-15T00:21:45Z")
Closed on June 15, 2025, 12:21am UTC This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.