Project Hub /Basic Analog & Power Electronics/Discrete & Component Electronics/DAC MCP4921 Interfacing with PIC Microcontroller PIC16F877A

Intermediate

PIC

₹500 – ₹1,500

3 – 6 Hours

Partial Kit

DAC MCP4921 Interfacing with PIC Microcontroller PIC16F877A

Learn how to interface the 12-bit MCP4921 Digital-to-Analog Converter (DAC) with a PIC16F877A microcontroller using the SPI protocol.

Originally published on CircuitDigest

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

10pcs - 220 ohm 1/4 W Resistor Set Rs. 39.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

This list includes a generic resistor set as a placeholder — it is not matched to the exact value or part number this circuit needs. The correct one is specified on the original source page linked above; check it before buying.

We don't carry yet: LCD (generic / unspecified)
ADC / DAC (ADS1115 / MCP3008 / MCP4725)
PIC Microcontroller
Crystal / Oscillator
Capacitors
USB Host / Programmer (ISP/USBasp)

Browse all components

How It Works

This project centers around converting digital data from a PIC16F877A microcontroller into a precise analog voltage using the MCP4921 Digital-to-Analog Converter IC. At the heart of the digital processing is the PIC16F877A microcontroller, which relies on a 20 MHz crystal oscillator paired with two 33pF capacitors to establish its high-speed clock signal. Powered by a stable 5V power supply, the microcontroller processes user inputs and communicates directly with the 12-bit MCP4921 DAC utilizing the Serial Peripheral Interface (SPI) protocol over hookup wires on a breadboard. The MCP4921 takes this serial digital word and translates it into a corresponding analog output voltage. To provide visual feedback of the system's operation and current settings, a 16x2 character LCD is connected to the microcontroller, with a 2k ohm resistor typically used for contrast adjustment and a 4.7k ohm resistor potentially utilized for pull-up or current-limiting functions. During testing and calibration, an external multimeter is used to measure and verify the analog output voltages generated by the DAC against the expected digital values, ensuring accurate performance across the entire 12-bit conversion range.

Why Build This

Gain practical undergraduate-level experience interfacing digital microcontrollers with precision analog peripherals using synchronous serial communication.

Understand the implementation of digital-to-analog conversion for real-world engineering applications such as adjustable power supplies and signal generation.

Develop hands-on debugging skills by verifying firmware-driven analog output levels using a standard laboratory multimeter.

Real-World Application

Motor control, controlling the brightness of LED lights, audio amplifiers, video encoders, and data acquisition systems.

Skills You'll Learn

SPI communication protocol

DAC interfacing

microcontroller clock configuration

LCD interfacing

analog voltage measurement and calibration

Safety Precautions

No specific precautions noted for this build — always follow general electronics safety practices.

Frequently Asked Questions

Why is a 20 MHz crystal used with the PIC16F877A?

The 20 MHz crystal and its associated 33pF capacitors provide the external clock source required for the microcontroller to execute instructions at the high speeds necessary for reliable SPI communication and display refreshing.

How does the microcontroller talk to the MCP4921 DAC?

They communicate using the Serial Peripheral Interface (SPI) protocol, where the PIC microcontroller acts as the master device sending 12-bit digital data packets to the DAC.

What is the purpose of the multimeter in this setup?

The multimeter is used as a test and measurement tool to physically verify that the analog voltage outputted by the MCP4921 matches the expected values calculated in your microcontroller program.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

PRJ-00080