Project Hub /Basic Analog & Power Electronics/Interfacing ESP8266 with PIC16F877A Microcontroller

Intermediate

ESP8266

₹500 – ₹1,500

3 – 6 Hours

Partial Kit

Interfacing ESP8266 with PIC16F877A Microcontroller

Learn how to interface the ESP8266 WiFi module with a PIC16F877A microcontroller using AT commands and USART communication.

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.

NodeMCU ESP8266 WIFI development board based on CP2102 Rs. 660.00
16×2 LCD Display with Pre-Soldered I2C Adapter Rs. 399.00
10pcs - 220 ohm 1/4 W Resistor Set Rs. 39.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
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: PIC Microcontroller
Crystal / Oscillator
Voltage Regulator IC (7805 / LM317 / 1117)
USB Host / Programmer (ISP/USBasp)
Capacitors

Browse all components

How It Works

This project bridges classic wired microcontroller architecture with modern wireless internet connectivity by interfacing an ESP8266 WiFi module with a PIC16F877A microcontroller. The system is powered by a 12V adapter, which is stepped down to stable logic voltages using a 7805 linear voltage regulator for the 5V PIC16F877A and an LM317 variable voltage regulator to supply the 3.3V required by the ESP8266. The PIC16F877A serves as the central processing unit, driven by a 20MHz crystal oscillator and associated 33pF capacitors for precise timing. Firmware developed using the MPLAB XC8 compiler allows the PIC microcontroller to communicate with the ESP8266 via USART serial communication using AT commands. User feedback and system status are visually rendered on a 16x2 LCD display connected through a circuit utilizing 220-ohm and 360-ohm resistors for contrast and backlight control. Additionally, resistors like the 1K value are used for pull-ups or voltage division to safely step down the 5V UART signals from the PIC to the 3.3V tolerant logic levels of the ESP8266. Capacitors such as 1uF and 0.1uF are placed across power rails for decoupling and noise filtering, ensuring stable operation during high-current wireless transmissions. The PicKit3 programmer is used to flash the compiled code onto the PIC16F877A, enabling the entire hardware setup to be prototyped and tested virtually in Proteus before physical deployment.

Why Build This

Upgrade legacy or custom 5V microcontroller systems with modern IoT and wireless connectivity capabilities.

Gain hands-on experience bridging disparate logic voltage domains (5V and 3.3V) in embedded hardware design.

Master serial communication protocols (USART) and AT command structures between independent processing modules.

Real-World Application

Adding wireless connectivity and IoT capabilities to legacy or custom microcontroller systems using inexpensive WiFi modules.

Skills You'll Learn

USART serial communication

microcontroller firmware development

multi-voltage power supply design

logic level translation

LCD display interfacing

in-circuit programming

Safety Precautions

Ensure correct voltage regulation: the PIC microcontroller operates at 5V while the ESP8266 operates at 3.3V and requires a 3.3V logic level converter/potential divider on RX pins and a robust 3.3V power supply capable of sourcing up to 800mA.

Technology Tags

PIC16F877A

ESP8266

WIFI

UART

USART

AT COMMANDS

EMBEDDED SYSTEMS

C PROGRAMMING

LCD DISPLAY

Frequently Asked Questions

Can I power the ESP8266 directly from the 5V output of the 7805 regulator?

No, the ESP8266 operates strictly at 3.3V and can be permanently damaged by 5V logic or power sources. You must use the LM317 variable regulator to supply a dedicated 3.3V rail capable of sourcing up to 800mA.

Why do I need a voltage divider or logic level converter on the RX pins?

The PIC16F877A outputs 5V signals on its TX pin, but the ESP8266 input pins are only 3.3V tolerant. Using resistors like a 1K divider prevents overvoltage damage to the WiFi module.

How do I upload the code to the PIC16F877A microcontroller?

You use a PicKit3 programmer connected to the appropriate programming pins (ICSP) on the PIC16F877A, utilizing the hex file generated by the MPLAB XC8 compiler.

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.

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