MCP4141 based digital potentiometer

The main objective of this project is to create an experimental prototype of a digital potentiometer using Microchip's MCP4141 IC. MCP4141 is available with end-to-end resistances of 5KΩ, 10KΩ, 50kΩ, and 100KΩ. This potentiometer-module can drive MCP4141 with any of the above mention resistances.

3D view of MCP4141 based digital potentiometer PCB

To drive the MCP4141, this module use ATtiny13 MCU. This MCU control MCP4141's resistance, based on the rotary-encoder events. ATtiny13 is an 8-pin, low power 8-bit MCU with an internal oscillator. The key reason to pick this MCU is its availability and lower price. Due to a lack of hardware-based SPI, this system use bit-banging SPI implementation to drive the MCP4141 IC.

To reduce the board size, this module employs only 3 components. Which including ATtiny13, MCP4141, and rotary-encoder. The dimension of the PCB design given for this module is 26.16mm × 29.72mm.

Breadboard wiring diagram

This is an open-source hardware project. Compiled firmware, PCB designs, schematic, and source codes related to this project are available at the GitHub project repository.

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