In the previous episodes of the ESP32 Portable Wi-Fi Scanner project, we built the project step by step.

In Episode 1, we created a basic Wi-Fi scanner that displayed nearby networks on the Serial Monitor.

In Episode 2, we added a 2.8-inch TFT display and built the graphical display framework using the ST7789 controller.

In Episode 3, we combined the Wi-Fi scanner with the TFT display and created a working graphical Wi-Fi scanner.

Now, in Episode 4, we take another major step toward making the project a portable wireless scanner.

We add two important features:

Bluetooth Low Energy (BLE) scanning
Battery support using an 18650 Li-ion battery and TP4056 charging module

What We Are Building

The ESP32 has built-in support for both Wi-Fi and Bluetooth Low Energy, which makes it an excellent platform for creating a compact wireless scanner.

With the additions in this episode, our project can now scan for:

Wi-Fi networks
BLE devices

The TFT display provides a convenient way to view the scan results.

We also add battery power so the project no longer needs to remain connected to a USB cable during normal operation.

Project Evolution

The project has now evolved through four stages.

EP1 – Basic Wi-Fi Scanner

We started with a simple ESP32 Wi-Fi scanner. The results were displayed through the Serial Monitor.

EP2 – TFT Display Framework

We introduced the 2.8-inch TFT display and configured the ST7789 driver. This episode focused mainly on creating the graphical display framework.

EP3 – Wi-Fi Scanner + TFT

We combined the Wi-Fi scanner with the TFT interface. The display now showed information such as:

SSID
RSSI
Channel
Security

We also solved an important hardware issue where the TFT would occasionally turn white during repeated Wi-Fi scans.

EP4 – Wi-Fi + BLE + Battery

In this episode, we extend the project by adding:

BLE scanning
BLE device information
Battery support
18650 Li-ion battery
TP4056 charging module

Adding Battery Support

Until now, the project was primarily powered through USB. That is convenient during development, but it isn’t ideal for a portable scanner.

To make the project portable, we added an 18650 Li-ion battery and a TP4056 charging module.

The basic idea is:

18650 Li-ion Battery
│
▼
Power Circuit
│
▼
ESP32
│
├── TFT Display
└── Wi-Fi / BLE

The TP4056 module provides a convenient way to charge a single-cell Li-ion battery.

Why Battery Support Matters

Adding a battery changes the project significantly.

Previously:

ESP32 + TFT
│
USB
│
Power

Now:

This allows the scanner to be used as a handheld device rather than being permanently connected to a computer.

It also makes testing much more convenient because the scanner can be carried around while scanning different locations.

Adding BLE Scanning

The ESP32 includes Bluetooth Low Energy functionality in addition to Wi-Fi. This makes it possible to discover nearby BLE devices without adding a separate Bluetooth module. The BLE scanner searches for advertising devices in the surrounding area.

Depending on the device, the scan will provide information such as:

Device name
Bluetooth address
RSSI
Number of detected devices

The RSSI value provides an indication of the received signal strength.

BLE Information on the TFT

The TFT display is used to present the BLE scan results.

A typical BLE scan can look like:

BLE Device	RSSI
Unknown	-95
BLE Device	-90
Sensor	-88
Tracker	-83

Not every BLE device necessarily broadcasts a readable name. Therefore, it is normal to see entries such as:

Unknown

or an address instead of a device name. This depends on what information the BLE device includes in its advertising packets.

Wi-Fi and BLE

One of the advantages of using the ESP32 is that we don’t need separate hardware for Wi-Fi and BLE scanning. The ESP32 provides both wireless technologies on the same chip.

This makes the project considerably more compact.

Portable Enclosure

For this version, the components are assembled into a compact enclosure.

The current prototype contains:

ESP32 development board
2.8-inch TFT display
TP4056 charging module
18650 battery
Wiring and supporting components

The enclosure is still a prototype rather than a finished product. It will be completed once we include all the features in the Project.

Wi-Fi Scanner Display

No change in Wi-Fi Scanner display from EP3

BLE Scanner Display

The BLE screen uses a similar concept.

BLE Device	RSSI
Unknown	-95
BLE Device	-90
Sensor	-88
Tracker	-83

Testing the Portable Scanner

Once the BLE scanner and battery support were added, the next step was to test the complete system.

The test verifies that:

ESP32 starts correctly
TFT initializes correctly
Wi-Fi scanning works
BLE scanning works
Scan results appear on the display
Battery power can operate the system
The charging circuit can be used to recharge the battery

The device can now be disconnected from the USB cable and used as a portable scanner, subject to the battery/power arrangement used in the prototype.

Hardware Used

The main hardware for this episode includes:

ESP32 DevKit board
2.8-inch 240×320 TFT display
ST7789 TFT controller
18650 Li-ion battery
TP4056 charging module
Jumper wires
Prototype enclosure

The same TFT setup from Episode 3 is retained.

Software Used

The project continues to use:

Arduino IDE
ESP32 board package
TFT_eSPI library
ESP32 Wi-Fi functionality
ESP32 BLE functionality

The display continues to use the ST7789 configuration developed in Episode 2. Source code you can download from github repo : https://github.com/pintushaw/WifiScanner

What We Learned

Episode 4 introduces several important concepts:

1. ESP32 Dual Wireless Capability

The ESP32 can handle both Wi-Fi and BLE, making it possible to build multi-purpose wireless projects without additional radio modules.

2. BLE Scanning

We learned how to discover nearby BLE advertising devices and retrieve information such as device name, address and RSSI.

3. Battery-Powered ESP32

Adding a rechargeable battery changes the project from a USB-powered development setup into a potentially portable device.

4. Hardware Integration

The project now combines several subsystems:

ESP32
TFT
Wi-Fi
BLE
Battery
Charging circuit

ESP32 Wi-Fi Scanner Project EP4 – Add BLE Scanner and Battery Support