Smart & Manual Home Automation with Alexa & ESP8266

Overview
In this
IoT project
, I demonstrate how to set up Smart
Home Automation
with
Alexa
using the
ESP8266
and
Amazon Echo Dot
. This ESP8266 Alexa Home Automation project solely relies on the
Amazon Alexa App
for controlling home devices with 4
relays
. Even without the internet, you can manage devices with
push buttons
. Once the device is online, the NodeMCU ESP8266 auto-connects to
WiFi
, preserving the relay module’s last state.
Earlier we built
Alexa Home Automation with fauxmoESP
Library, but here we used Espalexa Library. I have designed the
custom PCB
for this project to make the device portable. I have also provided the complete
schematic
, PCB details,
Gerber File
, Bill of Materials and Source Code. The system works without any third-party IoT apps, making it straightforward for
home automation setup
Bill of Materials
For this project, we will need the following components. The component list, footprint, and quantity are given below.
S.N.
Component
Designator
Footprint
Quantity

Capacitor 100nf
C1, C3, C5, C7, C8, C9, C10, C11
C0805

Capacitor 10uf
C2, C4, C6
C0805

Capacitor Electrolytic 100uf/25v
C12
CAPPRD250W52D630H1250

Capacitor Electrolytic 47uf/25v
C13
CAPPRD200W55D500H1200

Didoe 1N4007 SMD
D1, D2, D3, D4
DIOM5027X262N

Optocoupler IC PC817
IC1, IC3, IC4, IC5
DIP762W60P254L458H450Q4N

ESP-12E WiFi Module
IC2
ESP8266-12E

Terminal Block (1x2)
J1
1935776

Terminal Block (1x3)
J2, J3, J4, J5
1985894

Relay SRA-05VDC
K1, K2, K3, K4
SRA-05VDC-CL

LED Red
LED1, LED2, LED3, LED4, LED5
LED0805

PROG (1x6 Header)
P1
HDR1X6

HLK-10M05 AC-DC 5V
PS1
HLK10M05

Transistor BC847 SMD
Q1, Q2, Q3, Q4, Q5, Q6
BC847B

Resistor 220R
R1, R3, R9, R11, R14, R16, R17, R19
R0805

Resistor DNP
R2, R10, R15, R18
R0805

Resistor 12K
R4, R5, R6, R7, R8, R12, R13
R0805

Resistor 10K
R20, R21, R22, R23
R0805

Resistor 1k
R24, R25, R26, R27, R28
R0805

Push Button Switch
S1, S2, S3, S4, S5
B3W-1020

HT7333 3.3V LDO
U1
IC_HT7333

Circuit Diagram & Hardware Design
Let us take a look at the
Schematic
of Alexa Smart Home Automation Project with ESP8266. The schematic is drawn using the
Altium Designer
Software.
We used SMD resistors, capacitors, and LED with the 0805 package. To convert
220V AC
to
5V DC
, we used an
AC-to-DC Converter
from
Hi-Link
. For providing power to ESP8266 raw chip and other peripherals, a low-power
LDO HT7333
IC was used. To separate the high-power line from the 3.3V circuit
PC817 optocoupler
IC is used. The LED5 in the circuit is used to indicate power.
Similarly the
LED1, LED2, LED3
&
LED4
is used to represent
Relay1, Relay2, Relay3
&
Relay4
output respectively. The 4 Relays are connected to ESP8266 via GPIO16, GPIO14, GPIO12, GPIO10. A Reset button when pressed resets the ESP8266 Chip. The push buttons
SW1, SW2, SW3
, and
SW4
are used in the manual controlling of Relays. They are connected to GPIO5, GPIO4, GPIO2 & GPIO13. You may attach a
manual switch
there and program the controller to control the circuit.
To program the ESP8266 Board, the
Prog pin
is provided. We can connect an
FTDI Module
to program the ESP8266 Chip directly. Two large value capacitors
C12 (100uF)
and
C13 (47uF)
are added to control voltage fluctuations.
Project PCB Gerber File & PCB Ordering Online
We have designed the
PCB
using the
Altium Designer Software
. It took quite a lot of time fixing all the isses in the PCB but still we managed to design a complete working custom PCB. The PCB design looks like this.
Here is the
3D View
of the PCB from the front side as well as from the backside.
PCB Front Side
PCB Back Side
The Gerber File for the PCB is given below. You can simply download the Gerber File and order the PCB from
PCBGOGO
at
1$
only.
Download Gerber File:
ESP8266 Home Automation Gerber File
You can use this Gerber file to order high-quality PCB for this project. To do that visit the
PCBGOGO
official website by clicking here:
https://www.pcbgogo.com/
You can now upload the Gerber File by choosing the Quote Now option. From these options, you can choose the Material Type, Dimensions, Quantity, Thickness, Solder Mask Color and other required parameters.
After filling all details, select your country and shipping method. Finally you can place the order.
PCB & Hardware Assembly
After ordering the PCB, it took almost 5 days and I got my PCB.
The PCB quality from
PCBGOGO
is superb with very high quality. That is why most people trust
PCBGOGO
for PCB/PCBA Services.
First solder all the
SMD components
like resistors, capacitors, transistors, LEDs, voltage regulators & diodes. Be careful about the SMD LED polarity, place it in the proper direction. The SMD soldering is to be done on the both sides.
After soldering all these, you can solder the
ESP8266 raw chip
. The final stage would be soldering all the through-hole components like Optocoupler IC, terminal block, Relays, male-female headers, and AC-to-DC Converter Module.
After soldering all the components, the ESP8266 Alexa Smart Home Automation Board is ready for the test. You can upload a blink sketch by connecting a
USB-to-TTL Converter
Module.
Note:
There were some voltage fluctuation issues in the designed PCB, so I have updated the design by adding some large capacitors. Also, some connection issues have been fixed. The Gerber file above is updated and the PCB would be little different from shown above. But overall the functionality is same.
Espalexa Library
In this project, we will be using the
Espalexa library
to integrate the
ESP8266 Home Automation
Board with
Alexa Echo Dot
Download
:
Espalexa Library
So, you’ve got this cool library called
Espalexa
. What’s it all about? Imagine being able to chat with Alexa and get her to control your
ESP gadgets
, whether they’re ESP8266 or ESP32. This library makes that chat a breeze, and the best part? It’s all packed into an
Arduino-friendly
format.
Now, what sets Espalexa apart from other similar tools? Well, it gives you a ton of flexibility with
voice commands
. Instead of just turning things on or off, you can get precise. Tell Alexa, “Hey, dim that light to 75%,” or “Can we get the room to 21 degrees?” And she’ll handle it.
Even cooler? Espalexa has jumped onto the
color train
! Now you can say, “Alexa, let’s get a blue mood in here,” and your light will change color. If you’re more into shades of white, it’s got you covered too. By the starting line, Espalexa can juggle up to
10 devices
Source Code/Program for ESP8266 Alexa Home Automation Project
Here is the
code
for the
Smart
&
Manual Home Automation
Project with
Alexa
&
ESP8266
. This code is all about giving you two ways to
control devices
in your home. Imagine you have four lamps, and each lamp is connected to a
relay
(which is like a remote-controlled switch). Now, with this code:
You can ask Alexa to turn on or adjust any of these lamps. “
Alexa, turn on Lamp 1!
” and it’ll do just that.
But what if your internet goes down? No worries! There are manual switches you can press to control the lamps too.
The system is smart enough to keep checking if it’s connected to the internet. If it finds a connection, it’ll set itself up so you can use Alexa. If not, it’ll keep working with the manual switches.
Here is the complete code. In this code make changes to the
WiFi SSID
and
Password