diff --git a/README.md b/README.md index 9b0e2d4..f8f3fe2 100644 --- a/README.md +++ b/README.md @@ -3,10 +3,14 @@ > MCP4141 and ATtiny13 based digital potentiometer to replace an > existing 3 terminal analog potentiometers. +![Breadboard View](https://github.com/dilshan/mcp4141-digital-pot/raw/master/resources/digipot_breadboard.jpg) + The main objective of this project is to create a prototype version 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. 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. +![Schematic](https://raw.githubusercontent.com/dilshan/mcp4141-digital-pot/master/resources/schematic.svg?sanitize=true) + 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 x 29.72mm. ## Building and flash firmware