# Active-3 adapter and I2c devices

**URL:** <https://rpi-rgb-led-matrix.discourse.group/t/active-3-adapter-and-i2c-devices/389>\
**Category:** Uncategorized\
**Created:** [December 27, 2021, 11:40pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/active-3-adapter-and-i2c-devices/389 "2021-12-27T23:40:35Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![jackjacquejack](https://avatars.discourse-cdn.com/v4/letter/j/34f0e0/32.png) [@jackjacquejack](https://rpi-rgb-led-matrix.discourse.group/u/jackjacquejack)\
**Post date:** [December 27, 2021, 11:40pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/active-3-adapter-and-i2c-devices/389/1 "2021-12-27T23:40:36Z")

</div>

hello =)

I’d like to be able to run the active-3 adapter plus some i2c devices (mcp23017’s for GPIOs expansion). Has anyone done this? there doesn’t appear to be 2 available spare pins for the i2c communication.

Perhaps it’s possible to run two chains and some i2c devices. My project needs loads of inputs and outputs, 12 of each.

Any info would be greatly appreciated. thanks in advance =)

---

<div class="post-metadata">

**Author:** ![tjr](https://avatars.discourse-cdn.com/v4/letter/t/7993a0/32.png) [@tjr](https://rpi-rgb-led-matrix.discourse.group/u/tjr)\
**Post date:** [December 30, 2021, 1:34pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/active-3-adapter-and-i2c-devices/389/2 "2021-12-30T13:34:14Z")

</div>

Hello Jackcubed,

I have a fair amount of experience with that MPC23017 part. It is a GREAT part, but be aware that you can’t use a7 or b7 as an INPUT! I can’t help much with the other parts of your application.

---

<div class="post-metadata">

**Author:** ![jackjacquejack](https://avatars.discourse-cdn.com/v4/letter/j/34f0e0/32.png) [@jackjacquejack](https://rpi-rgb-led-matrix.discourse.group/u/jackjacquejack)\
**Post date:** [January 2, 2022, 6:07pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/active-3-adapter-and-i2c-devices/389/3 "2022-01-02T18:07:21Z")

</div>

yeah, they’re an incredible device. so many pins with such speed. interesting about the pins A7 and B7. I did not know that.

---

<div class="post-metadata">

**Author:** ![jackjacquejack](https://avatars.discourse-cdn.com/v4/letter/j/34f0e0/32.png) [@jackjacquejack](https://rpi-rgb-led-matrix.discourse.group/u/jackjacquejack)\
**Post date:** [January 2, 2022, 6:11pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/active-3-adapter-and-i2c-devices/389/4 "2022-01-02T18:11:21Z")

</div>

perhaps pyFirmata could be an alternative option. would be so nice to control the full number of screens AND have 100’s of GPIO pins with the MCP23017.