Introduction: HomeFi - Wifi Printed Circuit Board

Have you ever imagined creating a home automation card with Wifi or using it to program the ESP-01?

Many people need these features and because of that, I decided to teach you how to build your own home automation WIFI card with ESP01.

The following is the complete list of electronic components for you to design this Instructable.

In addition, I make the HomeFi Board files available for you to purchase on the JLCPCB website for $ 2.
You can download the files from the following link: download


  • 1 x ESP01 Wifi CHIP
  • 2 x Diode 1N4001
  • 1 x ASM1117 3.3V
  • 1 x ASM1117 5V
  • 1 x Jack Connector
  • 2 x Capacitor 0.33 uF
  • 2 x 0.1 uF
  • 1 x Relay SRD-05VDC-SEL-C
  • 1 x Header Female 2x4 - 2.54mm
  • 1 x Screw Connector WJ126V-5.0-3P
  • 1 x LED 3mm
  • 3 x 1kR Resistor
  • 1 x 330R Resistor
  • 1 x Header Male 1x2 2.54mm
  • 1 x Switch Button 6x6x5mm
  • 1 x BC337 Transistor
  • 1 x Male Header 90º 1x5 2.54mm

Step 1: The Wifi Board ESP-01

The ESP8266 Module is an Internet of Things (IoT) device that is made up of a 32-bit ARM microprocessor with WiFi technology and has integrated flash memory. Through this board, we can do the programming and communicate our projects with the internet.

In addition, it is possible to communicate the WIFI ESP-01 module with Arduino. That way we can connect our Arduino data to the internet.

This card is widely used by beginners because it has a low cost and small size. However, one of the major problems is its difficulty in flashing. There are some shields on the market, however, they do not offer all the features needed for ESP-01 programming.

Based on this, we decided to add a feature to allow ESP01 to be programmed on the HomeFi card itself. This facilitates programming and prevents the user from using other boards and increasing the cost of the project.

Therefore, the HomeFi board has 3 important features:

  • Home Automation with Relay;
  • Didactics for ESP01 programming learning;
  • The programmer of ESP-01.

Hereafter, we'll explain how to create the electronic schematic and understand all circuits of the HomeFi.

Step 2: The Electronic Schematic of the HomeFi Printed Circuit Board

This electronic schematic was created to allow programming the ESP-01 and use the relay to create automation systems. Therefore, in the next steps, we'll present each part of this electronic circuit.

The ESP01 Adapter of the Printed Circuit Board is divided into several parts:

  • Power Supply
  • Relay Driver
  • Circuit for programming ESP-01
  • ICSP Circuit Programming
  • Energized Signal LED
  • Input Voltage Pin;
  • ESP-01 Connector;

After this, I'll teach you how to understand each part of this schematic.

Step 3: Power Supply Circuit

In this region of the circuit were used two ASM1117 Voltage Regulator CHIP. Was used the ASM1117 3.3V and ASM1117 5V. The ASM1117 3.3V was used to power supply the ESP-01 and the ASM1117 5V was used to power supply the relay circuit.

In addition, was used the diode 1N4001 in the input voltage circuit. This diode is used to prevent the inverse voltage in the DC Jack 2.1 mm connector. This diode prevent occur problems of inverse voltage in other components.

These two voltage regulators are surface mounted devices and are very easy to use. Therefore, they are fundamental to supply voltage for other components.

Hereafter, we'll explain the circuit of Energized Signal LED and Input Voltage Pin.

Step 4: Circuit of Energized Signal LED and Input Voltage Pin.

In the section are presented two circuits: The Circuit of Energized Signal LED and the Input Voltage Pin.

The LED signaling circuit used to signalize that the circuit is powered on. This circuit is connected directly with AMS1117 5V. In this way, when the system is powered on the LED will be energized to indicate that the system is powered on.

In addition, there is a header male input voltage. This pin is used to offer the input volta for the user. Through this pin, the user can use the input voltage of the board to supply other circuits with the input voltage value. The voltage value on this pin is equal to the input voltage minus 0.7V, because of the voltage drop in the diode.

Now, we will discuss the operation of the ESP-01 programming circuit.

Step 5: ESP-01 Programming Circuit

The ESP-01 is programmed through its RX and TX serial communication pins. For this, we use a USB-TTL converter to transfer the data from the USB to the ESP-01.

First, you must choose a USB-TTL converter and connect it to the header male P1. After connecting the USB-TTL converter and the Header Male, you must press the reset and flash buttons to put the ESP-01 in programming mode.

Then start transferring the code to ESP-01.

For programming the HomeFi board we can use the FT232RL module, as is shown in the image above.

In addition to the Programming Circuit for ESP-01, there is a relay driver circuit as it will present in the next step.

Step 6: Relay Driver Circuit

In this printed circuit board there is a relay to activate a load of a higher power. To activate the load is needed use the transistor to switch the relay and the 1N4001 diode to protect the circuit against reverse peak voltage.

The relay has two contacts Normal Closed (NC) and Normal Open (NO).

In this way, is possible to create projects to automatize its residence and other processes that need to activate a load with a higher power through the relay.

Finally, through this project, you can generate your Gerber file and send for JLCPCB.COM and produce your own PCBs.

For this, access the project and purchase your own HomeFi Printed Circuit Boards through this link: Access the HomeFiBoard

Step 7: Acknowledgments

Thanks, JLCPCB.COM to the support to make this project