NORA — Nomadic Omnidirectional Reactive Automaton

Overview

Any direction, no turning

Move

Omnidirectional

Mecanum wheels let her drive, strafe and turn in place.

Host

The fleet's network

She runs the NORA access point and the fleet registry on port 5000, so no router is needed.

Protect

Four-way braking

HC-SR04 sensors front, back, left and right block any drive command that would hit something, with a buzzer warning.

Music

MP3 player

Play, skip, repeat and volume from the web, the remote or the controller. A single clap starts the music.

Sense

Environment

Temperature and humidity (AHT10), ambient light, and a 3-channel line sensor.

Clean

UV light

A UV LED that can be off, on or blinking.

Hardware

What she's built from

01 ESP32 (ACEBOTT QA007 Max controller board)
02 Arduino UNO + SparkFun MP3 Player Shield
03 Mecanum robot chassis
04 2× L298N motor drivers
05 4× 5 V DC motors
06 2S 18650 battery pack
07 4× HC-SR04 ultrasonic sensors
08 3-channel line tracking sensor
09 AHT10 temperature / humidity
10 Photoresistor and sound sensor
11 Buzzer and UV LED
12 IR receiver and IR transmitter LED

ESP32 pinout

Motors	PWM	Dir 1	Dir 2
M0 (front)	GPIO 5	GPIO 16	GPIO 17
M1 (front)	GPIO 23	GPIO 18	GPIO 19
M2 (rear)	GPIO 12	GPIO 13	GPIO 14
M3 (rear)	GPIO 27	GPIO 26	GPIO 25

Sensors & outputs	GPIO
Line follower L / M / R	34 / 35 / 39
UV LED	4
IR receiver (3.3 V)	32
IR transmitter	33
AHT10 SDA / SCL	21 / 22
UNO link	RX0 / TX0

UNO pinout

Ultrasonic	Pin
TRIG (all four joined)	A4
Front / right ECHO	A0 / A1
Back / left ECHO	A2 / A3

Other	Pin
Photoresistor	A5
Sound sensor	D5
Buzzer	D10
ESP32 link	D0 / D1

The MP3 shield reserves D2–D4, D6–D9 and D11–D13. The boards talk over a 9600 baud UART on their hardware serial pins, so unplug the link before uploading to either board.

# UNO → ESP32: distances in cm, track, music state, light %, sound flag
F:23.4,L:10.1,B:45.0,R:8.3,MT:101,MS:1,LT:62,SND:0

# ESP32 → UNO
M:PLAY  M:NEXT  M:PREV  M:STOP  M:REPEAT  V:UP  V:DOWN  V:MUTE
BZ:SPD:<0-100>  BZ:MODE:<0-3>  BZ:UV:<0-2>  BZ:LOCK:<0|1>  BZ:DENIED

Common GND is non-negotiable. If the motors behave erratically or the sensors read 0, check the ground bridge between every module first.

Drive modes

Four ways to move

1 · Manual

Web, controller, Bluetooth

D-pad control from the web page, the Python controller or Bluetooth serial.

2 · Auto

Obstacle avoidance

Omnidirectional avoidance using all four ultrasonic sensors.

3 · Line

Line following

Follows a line with the 3-channel sensor.

4 · IR remote

Direct driving

Hold a D-pad direction to drive and let go to stop. Enter swaps left/right between strafing and turning.

The mode keys, music, volume and mute work in every mode. The D-pad and Enter only drive in IR remote mode, so they never fight the web driver or the autonomous logic. There's no key-up over IR, so a 250 ms gap with no repeat counts as “released”. The web page also has a motor lock (password 1234 by default). The button map is in ir_mapping.txt.

Connect

Flash and join her network

Install the Arduino IDE with the ESP32 boards and the CH340 driver.
ESP32 libraries: IRremote 4.x and Adafruit AHTX0. UNO libraries: SFEMP3Shield and SdFat from the SparkFun MP3 Player Shield library.
For the ESP32, pick a bigger app partition under Tools → Partition Scheme: Huge APP (3MB No OTA/1MB SPIFFS) or Minimal SPIFFS (1.9MB APP with OTA).
Flash scripts/esp32 and scripts/arduino with the serial link unplugged, reconnect it, power her on and join her WiFi.

Setting	Value
WiFi SSID	`NORA`
Password	`12345678`
Control page	`http://192.168.4.1:5002`
Fleet registry	`http://192.168.4.1:5000`
Bluetooth	Device `NORA`

$ pip install -r requirements.txt
$ python scripts/controller.py              # WiFi
$ python scripts/controller.py --bt COM7    # Bluetooth serial

Fleet IR link

NORA drives IDA, MILA, WHIP and KIDA-01 through her IR transmitter on GPIO 33: Samsung-format IR, one address per robot, the same commands 0x48–0x4F for all. Pick the robot with the panel's tabs (or Tab in the Python controller); its avatar, name and colour follow. Drive commands repeat every 150 ms while held; each robot stops by itself if the link goes quiet.

Robot	Address	Receiver
IDA	`0x0DA1`	`IDA.ino`
MILA	`0x0DA2`	`MILA.ino`
WHIP	`0x0DA3`	`esp32.ino`
KIDA-01	`0x0DA4`	`arduino01` sketch

From	Drive	Stop	Obstacle	Manual	Speed
Web page	`I` `K` `J` `L`	button	button	button	button
Python controller	`I` `K` `J` `L`	release	`O`	`P`	`Y`
HTTP	`/link?r=mila&c=fw`	`stop`	`auto`	`manual`	`speed`
Bluetooth	`T` + robot `I M W K` + `F B L R`	`…S`	`…O`	`…W`	`…X`

Talking with the fleet

Every 30–90 s, when she isn’t driving anyone, NORA says something to IDA in Brainfuck: every phrase is a program that prints its words (hello is ++++++++[>+++++++++++++<-]>.+. → hi), beeped one tone per symbol. Once she’s finished she sends it over the link and IDA beeps her reply. RIFT has her chat with the other robots over WiFi too. A silent “I am here” beacon goes round the fleet in between, and IDA greets NORA when she comes back after a minute away. GET /talk returns the conversation log as JSON; /talk?r=ida&p=hello (or SAY HI on the panel) says one now. Phrases: 0x40 hello, 0x41 how are you, 0x42 happy, 0x43 curious, 0x44 sleepy, 0x45 let’s play, 0x46 bye, 0x47 “I am here” beacon (silent).

Connect through RIFT at the same address. Board docs: ACEBOTT ESP32 Max V1.0.

Who's nearby

ESP-NOW + Bluetooth LE: the robots sense each other

Every robot sends a small "I'm here" beacon twice a second. The signal strength says roughly how close each one is, and how it changes says whether it's coming closer, steady or leaving. Coarse, for "who's around": the ultrasonic and ToF sensors still do the precise avoiding.

Zones

Very close to far

Above −45 dBm very close, −60 near, −75 medium, below that far.

Talk

In Brainfuck

Over ESP-NOW each beacon carries a program that prints park, go, wait or hand; the receiver runs it. RIFT decodes them too.

Manners

Who makes way

A parked robot isn't the one moving; a yielding one is making way; a human-driven one gets space; otherwise the alphabet decides, and everyone makes way for MILA.

NORA hears the others over ESP-NOW (WHIP, MILA) and Bluetooth LE (WHIP and the Pi robots KIDA-00 / KIDA-01). In Auto mode she slows down while a robot is near and gives way when one with right of way is very close; in Line mode she waits on the line. GET /near shows her list.

Screens

The controllers

Captured without a robot connected, so live values show their offline state.

NORA's controller connection screen — Python controller (WiFi or Bluetooth)

NORA's web dashboard with distances, modes, music and drive pad — Web dashboard (served by the ESP32)

Voice

What NORA says

Her spoken lines, played from the MP3 shield's SD card (track200–track210). Made with make_voice.bat (Windows text-to-speech + ffmpeg).