• Ce face: utilizatorul introduce o sticla PET, masina o scaneaza, masoara dimensiunile si decide acceptarea sau respingerea ei pe baza unei baze de date configurabile.
• Scopul: demonstrarea integrarii mai multor periferice hardware (UART, SoftwareSerial, senzori ultrasonici HC-SR04, motoare DC cu L9110S H-bridge, display I2C) si aplicarea principiilor DDD (Domain-Driven Design) atat pe firmware cat si pe platforma web.
• Ideea de pornire: aparatele de colectare a ambalajelor din supermarketuri.
• Elementul distinctiv: frameworkul de simulare complet — firmware-ul poate rula cu toti senzorii inlocuiti de stubs software controlabile din interfata web, permitand testarea logicii fara niciun circuit conectat.

1. Operatorul porneste tranzactia din platforma web (CMD:START)
2. ATmega detecteaza sticla prin senzorul fotoelectric (IR slot) pe PD4
3. Scannerul E2100 citeste barcode-ul prin SoftwareSerial (PD2/PD3), ATmega il trimite catre PC
4. PC-ul cauta dimensiunile in baza de date si le trimite inapoi (DIMS:) sau DB:NOT_FOUND
5. HC-SR04 masoara inaltimea (PD7/PB0) si diametrul (PC0/PC3), firmware-ul valideaza dimensiunile
6. Daca acceptata: cele doua motoare DC (L9110S canal A PC1/PC2 + canal B PD5/PD6) pornesc inainte si antreneaza banda conveyor; LCD afiseaza “ACCEPTED”
7. Daca respinsa: motoarele pornesc in sens invers si returneaza sticla; LCD afiseaza “REJECTED”
8. PC-ul primeste RESULT:ACCEPTED / RESULT:REJECTED si actualizeaza dashboard-ul

flowchart TB
    User([Utilizator]) -->|introduce sticla PET 0.5L| irSensor

    irSensor["Senzor IR slot #1 - PD4"]
    e2100["E2100 Barcode Scanner - PD2/PD3 SoftwareSerial"]
    hcsr1["HC-SR04 #1 diametru - PD7 TRIG / PB0 ECHO"]
    hcsr2["HC-SR04 #2 inaltime - PC0 TRIG / PC3 ECHO"]

    irSensor --> ATmega
    e2100 --> ATmega
    hcsr1 --> ATmega
    hcsr2 --> ATmega

    subgraph ATmega["ATmega328P Xplained Mini"]
        rvm["RvmController - masina de stari"]
        lcd["LCD I2C 16x2 - PC4 SDA / PC5 SCL"]
        rvm --- lcd
    end

    ATmega -->|"L9110S canal A: PC1/PC2"| motorA["Motor DC #1 - conveyor perete stang"]
    ATmega -->|"L9110S canal B: PD5/PD6"| motorB["Motor DC #2 - conveyor perete drept"]
    ATmega <-->|"UART0 PD0/PD1 - ASCII 9600 baud"| web

    subgraph web["Platforma Web PC"]
        nodejs["Node.js + Express 5"]
        sqlite["SQLite + Drizzle ORM"]
        react["React 19 + Socket.IO"]
        nodejs --- sqlite
        sqlite --- react
    end

stateDiagram-v2
    [*] --> IDLE
    IDLE --> WAITING : CMD:START de la PC
    WAITING --> SCANNING : IR detecteaza sticla
    SCANNING --> MEASURING : BARCODE: primit + DIMS: de la PC
    SCANNING --> IDLE : DB:NOT_FOUND sau timeout scanare
    MEASURING --> TRANSPORTING : dimensiuni in toleranta
    MEASURING --> RETURNING : dimensiuni invalide
    TRANSPORTING --> IDLE : motoare STOP - RESULT:ACCEPTED trimis
    RETURNING --> IDLE : motoare STOP - RESULT:REJECTED trimis
    TRANSPORTING --> IDLE : timeout JAM - ERROR:JAM trimis
    IDLE --> IDLE : CMD:STOP / CMD:RESET

Pin    Functie              Modul conectat
------------------------------------------
PD0    UART0 RX             mEDBG USB (serial la PC)
PD1    UART0 TX             mEDBG USB (serial la PC)
PD2    SoftwareSerial RX    E2100 TX
PD3    SoftwareSerial TX    E2100 RX
PD4    GPIO input           Senzor fotoelectric slot #1 (LOW = sticla detectata)
PD5    GPIO output          L9110S B-IA (motor conveyor #2 directie A)
PD6    GPIO output          L9110S B-IB (motor conveyor #2 directie B)
PD7    GPIO output          HC-SR04 #1 TRIG (diametru)
PB0    GPIO input           HC-SR04 #1 ECHO (diametru)
PC0    GPIO output          HC-SR04 #2 TRIG (inaltime)
PC1    GPIO output          L9110S A-IA (motor conveyor #1 directie A)
PC2    GPIO output          L9110S A-IB (motor conveyor #1 directie B)
PC3    GPIO input           HC-SR04 #2 ECHO (inaltime)
PC4    I2C SDA              LCD I2C 16x2 (display stare masina)
PC5    I2C SCL              LCD I2C 16x2 (display stare masina)

Tabel conexiuni:

Nota alimentare: Motoarele si LCD-ul sunt alimentate de pe sina 5V a breadboard-ului (incarcator 5V 2A), nu de pe ATmega (limitat la 500mA USB). GND comun intre surse.

• PlatformIO cu framework Arduino, compilator avr-gcc 7.x, C++14
• Doua environment-uri: xplained_mini (hardware real) si xplained_mini_sim (simulare cu stubs)
• Script custom Python (set_upload_port.py) pentru upload prin mEDBG (interfata USB HID, nu serial clasic)

Arhitectura firmware (DDD pe ATmega):

• common/ — FixedString (string pe stack, fara alocare dinamica), RingBuffer, Timer
• domain/ — interfete pure C++: ICommChannel, IScanner, IBottleDetector, IHeightSensor, IDiameterSensor, ITransport, IDisplay
• application/ — RvmController (masina de stari IDLE→WAITING→SCANNING→MEASURING→TRANSPORTING/RETURNING→IDLE), BottleValidator
• infrastructure/ — UartProtocol, Gm65Scanner (E2100), IrBreakBeam, DcConveyor (L9110S dual motor), LcdI2cDisplay (PCF8574)
• stubs/ — StubScanner, StubHeightSensor, StubDiameterSensor, StubBottleDetector, StubTransport, StubDisplay, SimBridge

Decizii cheie firmware:

• Niciun delay() in logica aplicatiei — toate operatiile sunt non-blocking cu tick()
• Fara alocare dinamica (nu exista new, String, std::vector) — pe 2KB RAM, fragmentarea heap-ului e fatala
• Erori returnate prin enum-uri, nu exceptii (compilat cu -fno-exceptions)
• DcConveyor controleaza simultan ambele motoare: inainte (ACCEPT), inapoi (RETURN), stop

Platforma web (Node.js + React):

• shared — tipuri TypeScript comune (protocol serial, DTO-uri REST)
• server — Node.js 22, Express 5, SQLite + Drizzle ORM, serialport, Socket.IO 4, Zod
• client — React 19, Vite, Tailwind CSS v4, shadcn/ui, Recharts

Pagini: Dashboard (status live, START/STOP), Barcodes (CRUD), Transactions (istoric), Statistics (grafice), Simulation (control stubs)

Protocol serial ASCII (ATmega ↔ PC):

PC → ATmega:  CMD:START / CMD:STOP / CMD:RESET
              DIMS:220:65:10     (inaltime:diametru:toleranta in mm)
              DB:NOT_FOUND

ATmega → PC:  STATUS:IDLE / WAITING / SCANNING / MEASURING / TRANSPORTING / RETURNING
              BARCODE:5941234567890
              MEASURED:H=218:D=63
              RESULT:ACCEPTED / RESULT:REJECTED:oversized
              ERROR:JAM / ERROR:SCANNER_FAIL

Simulare:     SIM:BEAM:ON/OFF   SIM:BARCODE:<val>   SIM:HEIGHT:<mm>
              SIM:DIAM:<mm>     SIM:JAM             SIM:RESET_STUBS
              ATmega: SIM:ACK:<msg> / SIM:ERR:<motiv>

• Firmware-ul compileaza fara warninguri in ambele configuratii (productie si simulare)
• Build-ul de simulare testat pe ATmega328P Xplained Mini: comunicatia seriala, masina de stari si SimBridge functioneaza corect
• Platforma web functionala cu toate cele cinci pagini
• Script custom Python (set_upload_port.py) rezolva limitarea PlatformIO cu protocolul mEDBG
• Componentele hardware au sosit; urmeaza conectarea fizica si calibrarea