ESP32-S3 board
The brain of the build — with a Wi-Fi radio already aboard.
01 First, know the pieces
What you need
Three things on the bench, plus one you already own: the name and password of your 2.4 GHz Wi-Fi network. Have both written down before you start. Tap Define on anything unfamiliar — the answer opens as a field note you can read and dismiss without losing your place.
Arduino IDE
Uploads the sketch and opens Serial Monitor.
Official sketch
Sketch_23.1_WiFi_Station.ino
02 One action at a time
Build it
The whole day is edit two lines, upload, and read the monitor. Tap each step as you go to keep your place — you can finish without opening a single field note.
0 / 7 done
Plug the ESP32-S3 into your computer with a data-capable USB cable.
Open
Sketch_23.1_WiFi_Station.inoin Arduino IDE.Replace both
"********"strings with your own Wi-Fi name and password — keep the double quotes, and use your 2.4 GHz network.Select your ESP32-S3 board and its port, then press Upload.
Open Serial Monitor and set the baud rate to
115200.Watch
Setup start, then dots while the board negotiates, then the IP address your router assigns.Write that address in your logbook — Day 30 dials it.
03 Read just enough code
Read the code
The sketch is short enough to read whole. Two lines near the top hold the placeholders you replace with your own credentials; setup() does all the work and loop() stays empty. Switch to MicroPython if you'd rather see the same idea in Python.
#include <WiFi.h>
const char *ssid_Router = "********"; //Enter the router name
const char *password_Router = "********"; //Enter the router password
void setup(){
Serial.begin(115200);
delay(2000);
Serial.println("Setup start");
WiFi.begin(ssid_Router, password_Router);
Serial.println(String("Connecting to ")+ssid_Router);
while (WiFi.status() != WL_CONNECTED){
delay(500);
Serial.print(".");
}
Serial.println("\nConnected, IP address: ");
Serial.println(WiFi.localIP());
Serial.println("Setup End");
}
void loop() {
}WiFi.begin(ssid_Router, password_Router)Asks to join your router by name — station mode — using the credentials you typed into the two strings above. while (WiFi.status() != WL_CONNECTED)Waits for the router to accept the board, printing a dot every half second — and it will wait forever, so endless dots mean wrong credentials. Serial.println(WiFi.localIP())Prints the IP address your router assigned — the board's berth number, and the number Day 30 dials. Optional side path · no wiring
ssidRouter = '********' #Enter the router name
passwordRouter = '********' #Enter the router password
def STA_Setup(ssidRouter,passwordRouter):
print("Setup start")
sta_if = network.WLAN(network.STA_IF)
if not sta_if.isconnected():
print('connecting to',ssidRouter)
sta_if.active(True)
sta_if.connect(ssidRouter,passwordRouter)
while not sta_if.isconnected():
pass
print('Connected, IP address:', sta_if.ifconfig())
print("Setup End")network.WLAN(network.STA_IF)Creates the station interface — MicroPython's handle on the board's radio in join-a-network mode.sta_if.ifconfig()Returns the board's network details once connected — the first value is its IP address.Same radio, same credentials — replace both '********' strings before you run it in Thonny. If MicroPython isn't set up yet, skip this — it should never block the Arduino-first day.
04 Understand, don't memorise
One radio, two roles
Chapter 23 of the manual gives the radio three working modes. Today's upload is station mode — the board joins your network the way your phone does. The challenge flips it to access-point mode, where the board hosts a network of its own.
WiFi.begin
The board calls your router by name and offers the password.
Router checks
The router verifies the password and accepts the board onto the network.
DHCP assigns
The router hands the board an IP address of its own — its berth number.
localIP prints
The sketch prints that address so you can write it down for Day 30.
The two modes
station = join a network · access point = be the network
Where the address comes from
Your router runs a small harbourmaster service called DHCP. Every device that joins gets assigned a free berth — an IP address — which is why the one your board prints will differ from the one in this lesson.
Both roles at once
The third mode, AP+Station (Sketch_23.3_AP_Station), runs both at the same time — the board stays joined to your router while hosting its own network.
05 Know it worked
Test & debug
Success and recovery sit side by side, so you never have to go hunting when something looks off.
What you should see
Setup startConnecting to YourNetworkName......Connected, IP address: 192.168.1.23Setup End
Your network name and the address itself will differ — the IP is whatever your router assigns. A handful of dots is normal; they should stop within a few seconds.
If it doesn't
- Dots marching forever? The network name or password is wrong. Fix both strings in the sketch, re-upload, and press reset — the loop has no timeout.
- Your network never connects at all? The board speaks 2.4 GHz Wi-Fi only. Check that your router broadcasts a 2.4 GHz band.
- Blank monitor? Confirm 115200 baud, then the board and port.
- AP name missing from your phone's list? The access-point password must be at least 8 characters. Re-upload Sketch_23.2 and rescan.
06 Make the idea yours
Try this: be the network
Same board, opposite role. The second official sketch turns the ESP32-S3 into an access point — a network your phone can see and join. It fits inside today's 25 minutes.
Host your own network
Upload Sketch_23.2_WiFi_AP — the line WiFi.softAP(ssid_AP, password_AP) turns the board into an access point, and the monitor prints Soft-AP IP address = …. Your phone's Wi-Fi list now shows WiFi_Name; join it with the password 12345678.
Fly your own name
Change ssid_AP to your boat's name, pick a new password of 8 or more characters, and re-upload. Rescan on your phone and there it is.
Find the board on the chart
Back in station mode, open your router's device list and find your board there — the same IP address the monitor printed.
Logbook
07 Learn it with a hand on the tiller
Coach me through it
Every lesson ships with a code and a machine-readable packet, so an agent can guide you with full context.
Lesson code
TSK-DAY29-WIFI
Context packet
How the agent should behave: keep credentials private — the learner edits them into the sketch locally, never into chat — and check the 2.4 GHz band, both placeholder strings, and baud rate before changing code.