# IO Expander RGB LEDs
## Description
Design of an RGB LED control system using a TCA6424A I/O expander. Features multiple RGB LEDs driven by resistors via an I2C interface. Integrates power supply and reset circuitry.
## Project Details
- **Owner:** mmpp
- **Created:** 2/4/2025
- **Last Updated:** 2/4/2025
- **Visibility:** Public
- **License:** https://creativecommons.org/licenses/by/4.0/
## Key Components
### J1 — [Pin Header 01x06 2.54mm Vertical](https://www.flux.ai/vasy_skral/pin-header-01x06-254mm-vertical.md)
- Part Type: Connector
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- Pin_1 [pin 1]
- Pin_2 [pin 2]
- Pin_3 [pin 3]
- Pin_4 [pin 4]
- Pin_5 [pin 5]
- Pin_6 [pin 6]
### LED1 — [LTRBR37G-4R4S-0125-0-2-R18](https://www.flux.ai/vasy_skral/ltrbr37g-4r4s-0125-0-2-r18.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Name: ams-OSRAM USA INC.
- Datasheet URL: https://dammedia.osram.info/media/resource/hires/osram-dam-24639129/LTRB%20R37G_EN.pdf
- Manufacturer Part Number: LTRBR37G-4R4S-0125-0-2-R18
- Part Type: LED
**Pins:**
- A [pin 4]
- B [pin 3]
- G [pin 2]
- R [pin 1]
### LED2 — [LTRBR37G-4R4S-0125-0-2-R18](https://www.flux.ai/vasy_skral/ltrbr37g-4r4s-0125-0-2-r18.md)
- Datasheet URL: https://dammedia.osram.info/media/resource/hires/osram-dam-24639129/LTRB%20R37G_EN.pdf
- Part Type: LED
- Manufacturer Part Number: LTRBR37G-4R4S-0125-0-2-R18
- Manufacturer Name: ams-OSRAM USA INC.
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- A [pin 4]
- B [pin 3]
- G [pin 2]
- R [pin 1]
### LED3 — [LTRBR37G-4R4S-0125-0-2-R18](https://www.flux.ai/vasy_skral/ltrbr37g-4r4s-0125-0-2-r18.md)
- Datasheet URL: https://dammedia.osram.info/media/resource/hires/osram-dam-24639129/LTRB%20R37G_EN.pdf
- Part Type: LED
- Manufacturer Part Number: LTRBR37G-4R4S-0125-0-2-R18
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Name: ams-OSRAM USA INC.
**Pins:**
- A [pin 4]
- B [pin 3]
- G [pin 2]
- R [pin 1]
### LED4 — [LTRBR37G-4R4S-0125-0-2-R18](https://www.flux.ai/vasy_skral/ltrbr37g-4r4s-0125-0-2-r18.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Name: ams-OSRAM USA INC.
- Part Type: LED
- Manufacturer Part Number: LTRBR37G-4R4S-0125-0-2-R18
- Datasheet URL: https://dammedia.osram.info/media/resource/hires/osram-dam-24639129/LTRB%20R37G_EN.pdf
**Pins:**
- A [pin 4]
- B [pin 3]
- G [pin 2]
- R [pin 1]
### LED5 — [LTRBR37G-4R4S-0125-0-2-R18](https://www.flux.ai/vasy_skral/ltrbr37g-4r4s-0125-0-2-r18.md)
- Manufacturer Name: ams-OSRAM USA INC.
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: LED
- Manufacturer Part Number: LTRBR37G-4R4S-0125-0-2-R18
- Datasheet URL: https://dammedia.osram.info/media/resource/hires/osram-dam-24639129/LTRB%20R37G_EN.pdf
**Pins:**
- A [pin 4]
- B [pin 3]
- G [pin 2]
- R [pin 1]
### LED6 — [LTRBR37G-4R4S-0125-0-2-R18](https://www.flux.ai/vasy_skral/ltrbr37g-4r4s-0125-0-2-r18.md)
- Manufacturer Name: ams-OSRAM USA INC.
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://dammedia.osram.info/media/resource/hires/osram-dam-24639129/LTRB%20R37G_EN.pdf
- Part Type: LED
- Manufacturer Part Number: LTRBR37G-4R4S-0125-0-2-R18
**Pins:**
- A [pin 4]
- B [pin 3]
- G [pin 2]
- R [pin 1]
### LED7 — [LTRBR37G-4R4S-0125-0-2-R18](https://www.flux.ai/vasy_skral/ltrbr37g-4r4s-0125-0-2-r18.md)
- Datasheet URL: https://dammedia.osram.info/media/resource/hires/osram-dam-24639129/LTRB%20R37G_EN.pdf
- Part Type: LED
- Manufacturer Part Number: LTRBR37G-4R4S-0125-0-2-R18
- Manufacturer Name: ams-OSRAM USA INC.
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- A [pin 4]
- B [pin 3]
- G [pin 2]
- R [pin 1]
### LED8 — [LTRBR37G-4R4S-0125-0-2-R18](https://www.flux.ai/vasy_skral/ltrbr37g-4r4s-0125-0-2-r18.md)
- Manufacturer Name: ams-OSRAM USA INC.
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Part Number: LTRBR37G-4R4S-0125-0-2-R18
- Part Type: LED
- Datasheet URL: https://dammedia.osram.info/media/resource/hires/osram-dam-24639129/LTRB%20R37G_EN.pdf
**Pins:**
- A [pin 4]
- B [pin 3]
- G [pin 2]
- R [pin 1]
### U1 — [TCA6424ARGJR](https://www.flux.ai/adrian95/tca6424argjr.md)
- Part Type: Integrated Circuit
- Manufacturer Part Number: TCA6424ARGJR
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://www.ti.com/lit/ds/symlink/tca6424a.pdf
- Manufacturer Name: Texas Instruments Inc.
**Pins:**
- ~INT [pin 32]
- ~RESET [pin 28]
- ADDR [pin 26]
- EP [pin 33]
- GND [pin 25]
- P00 [pin 1]
- P01 [pin 2]
- P02 [pin 3]
- P03 [pin 4]
- P04 [pin 5]
- P05 [pin 6]
- P06 [pin 7]
- P07 [pin 8]
- P10 [pin 9]
- P11 [pin 10]
- P12 [pin 11]
- P13 [pin 12]
- P14 [pin 13]
- P15 [pin 14]
- P16 [pin 15]
- P17 [pin 16]
- P20 [pin 17]
- P21 [pin 18]
- P22 [pin 19]
- P23 [pin 20]
- P24 [pin 21]
- P25 [pin 22]
- P26 [pin 23]
- P27 [pin 24]
- SCL [pin 29]
- SDA [pin 30]
- V_CCI [pin 31]
- V_CCP [pin 27]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/mmpp/io-expander-rgb-leds](https://www.flux.ai/mmpp/io-expander-rgb-leds).*
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*Generated from [https://www.flux.ai/mmpp/io-expander-rgb-leds](https://www.flux.ai/mmpp/io-expander-rgb-leds)*