# Driving 2 chains and keeping GPIO pins free for buttons? **URL:** \ **Category:** Uncategorized\ **Created:** [November 14, 2025, 2:50pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/driving-2-chains-and-keeping-gpio-pins-free-for-buttons/1144 "2025-11-14T14:50:26Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![evilC](https://yyz2.discourse-cdn.com/free1/user_avatar/rpi-rgb-led-matrix.discourse.group/evilc/32/711_2.png) [@evilC](https://rpi-rgb-led-matrix.discourse.group/u/evilC)\ **Post date:** [November 14, 2025, 2:50pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/driving-2-chains-and-keeping-gpio-pins-free-for-buttons/1144/1 "2025-11-14T14:50:27Z")
I wish to drive 2 panels on a RPi Zero 2W. I don’t have my panels yet but am 99% sure each one only has inputs, so I am guessing that means 2 chains. I would also like to have some buttons to control functionality. I did buy an ElectroDragon active 3 port adapter board, which seems to use the whole GPIO header. Seeing as I envisage only needing 2 of the 3 ports, can I use some of the GPIO pins for buttons? Looking at the wiring diagram, it seems like there are 6 pins (The ones with the droplet icons) that are only used for chain 3, so could I just make sure that those 6 pins on the RPi are not long enough to engage into the adapter board, and just route them to buttons instead? ---
**Author:** ![marcmerlin](https://yyz2.discourse-cdn.com/free1/user_avatar/rpi-rgb-led-matrix.discourse.group/marcmerlin/32/40_2.png) [@marcmerlin](https://rpi-rgb-led-matrix.discourse.group/u/marcmerlin)\ **Post date:** [November 27, 2025, 6:31am UTC](https://rpi-rgb-led-matrix.discourse.group/t/driving-2-chains-and-keeping-gpio-pins-free-for-buttons/1144/2 "2025-11-27T06:31:13Z")
You are correct, the ED3 board is connected to the GPiO pins, but if you don’t use channel 3, the channel 3 pins will be free for other uses.