2023-09-15
Programming with ESP32: The ESP32 is a microcontroller widely used in embedded systems and IoT (Internet of Things) applications. This guide provides an introduction to programming with the ESP32, allowing you to harness its capabilities for various projects and IoT innovations.
Connect SoC (ESP32) with usb cable to computer. Do a check if ESP32 is visible.
ls -l /dev/ttyUSB*
crw-rw----+ 1 root dialout 188, 0 Sep 15 21:29 /dev/ttyUSB0
You may also need to your user to group dialout in order to accesible by arduino.
sudo usermod -a -G dialout $USER
ESP32 Dev Module from the "Boards" menu. This will install the Platform esp32:esp32@2.0.11.python3.11 -m pip install pyserial
UART, which stands for Universal Asynchronous Receiver-Transmitter, is used for serial communication.
Baud Rate: The baud rate represents the number of signal units per second that are transmitted over a communication channel.
9600 Baud: This means the signal can change state 9,600 times per second. In the context of UART, it typically means you can transmit 9,600 bits per second.
In UART, data is packaged in 8-bit frames, which include a start bit, data bits, an optional parity bit, and stop bit(s).
ESP32-WROOM Computer
+-----------------------------------------------------------------------+ +------------+
| | | |
| +------------+ +-------------+ | USB cable | |
| | | TX RX | | USB Port | <-----------> | USB Port |
| | | ------------------> | | | data + | |
| | | | | | power | |
| | ESP32 Chip | | CP210x Chip | | | |
| | | | USB-to-UART | | | |
| | | <------------------ | | | | |
| | | RX TX | | | | |
| | | | | | | |
| +------------+ +-------------+ | | |
| | | |
+-----------------------------------------------------------------------+ +------------+
Now here we have a code example that you can deploy this code to your ESP32 to scan for nearby WiFi networks endlessly. The results are sent over serial communication, and you can read them in the Arduino IDE's Serial Monitor. Plus, with each scan, the built-in LED on the ESP32 lights up.
#include <WiFi.h>
// Define the GPIO pin for the built-in LED
#define LED_PIN 2
void setup() {
// Initialize Serial communication
Serial.begin(115200);
delay(1000); // Give some time for Serial to initialize
// Print a welcome message
Serial.println("ESP32 Demonstration Program");
// Initialize the built-in LED as an output
pinMode(LED_PIN, OUTPUT);
}
void loop() {
// Blink the built-in LED
digitalWrite(LED_PIN, HIGH);
delay(1000);
digitalWrite(LED_PIN, LOW);
delay(1000);
// Scan for nearby WiFi networks
Serial.println("Scanning for WiFi networks...");
int n = WiFi.scanNetworks();
if (n == 0) {
Serial.println("No networks found");
} else {
Serial.print(n);
Serial.println(" networks found");
for (int i = 0; i < n; ++i) {
// Print SSID and signal strength for each network
Serial.print(i + 1);
Serial.print(": ");
Serial.print(WiFi.SSID(i));
Serial.print(" (");
Serial.print(WiFi.RSSI(i));
Serial.println(" dBm)");
delay(10);
}
}
delay(5000); // Wait for 5 seconds before scanning again
}