This 128 GPIO extension board provides 128 channels designed for use on the Raspberry Pi. The board is based around the MCP23017 16-bit I/O expander from Microchip Technology Inc.

Features:

• Eight MCP23017 expanders are included on the board allowing you to connect up to 128 digital inputs or outputs to the Raspberry Pi. The 128 GPIO board is powered through the host Raspberry Pi using the GPIO port and extended pins on the GPIO connector allow you to stack the 128 GPIO along with other expansion boards.
• Extra i2c pin for easy connections to other devices
• J1 i2c signal input for Pins 1-4 (GND, 5V, SDA, SCL)
  
• Compatible with Pi4 & Pi5
  

Technical specifications:

• 23017 U2, U3, U4, U5, U6, U7, U8, U9 with GPIO Port A and B
• Output of each GPIO to 2x10 pin:
• Bank B (1-10) GPIO (0, 1, 2, 3, 4, 5, 6, 7, GND, INTB)
• Bank A (1-10) GPIO (0, 1, 2, 3, 4, 5, 6, 7, GND, INTA)
• U1 (20)  23017 -1 Port A, B   
• U2 (21)  23017 -2 Port A, B
• U3 (22)  23017 -3 Port A, B   
• U4 (23)  23017 -4 Port A, B
• U5 (24)  23017 -5 Port A, B   
• U6 (25)  23017 -6 Port A, B
• U7 (26)  23017 -7 Port A, B   
• U8 (27)  23017 -8 Port A, B
• 23017 Datasheet
  

Demo software:

• led-21.py     led-22.py     23017-21.py     23017-22.py
• 23017-8port-s-v103.py
• led-8-v22.py

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