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--- pm:prj2026:vlad.radulescu2901:sebastian.coitu [2026/05/07 13:07]
sebastian.coitu
+++ pm:prj2026:vlad.radulescu2901:sebastian.coitu [2026/05/13 19:02] (current)
sebastian.coitu
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 ===== Introduction =====
-The **Smart Lamp** is an embedded system project that implements an adaptive LED lighting solution with two distinct operating modes, built around the ATmega328P Xplained Mini development board. In **Manual Mode**, the user controls the LED brightness directly via a potentiometer. The analog signal is read through ADC and converted to a PWM duty cycle that drives the LED. In **Automatic Mode**, a photoresistor senses the ambient light level, and the microcontroller automatically adjusts the LED brightness — brighter in dark environments, dimmer when the surroundings are already well-lit. At any moment, the current brightness level (0–100%) is displayed on a LCD connected via I2C. The user switches between modes by pressing the onboard button.
+The **Smart Lamp** is an embedded system project that implements an adaptive RGB LED strip lighting solution with two distinct operating modes, built around the **ATmega328P Xplained Mini** board. In **Manual Mode**, the user controls the LED brightness directly via a potentiometer. The analog signal is read through ADC and converted to three identical PWM duty cycles that drive the R, G, and B channels. In **Automatic Mode**, a photoresistor senses the ambient light level, and the microcontroller automatically adjusts the LED brightness — brighter in dark environments, dimmer when the surroundings are well-lit. At any moment, the current brightness level (0–100%) is displayed on a 16×2 LCD connected via I2C. The user switches between modes by pressing the onboard button.
 The motivation behind this project comes from two sources: the growing interest in smart home automation and energy-efficient lighting and the need for a compact and easy to use lamp for my desk. This auto-dimming lamp is a practical system that demonstrates core concepts for embedded projects.
 ===== General Description =====
+{{:pm:prj2026:vlad.radulescu2901:schema_bloc_v2.png?700|}}
-{{:pm:prj2026:vlad.radulescu2901:schema_bloc_sebastian_coitu.png?900|}}
+Block scheme description:
   * **ATmega328P Xplained Mini** — reads ADC inputs, generates PWM output for LED brightness control, drives the LCD over I2C, and handles button press interrupts to toggle modes.
-  * **LED + Current-Limiting Resistor** — is driven by a PWM signal on pin PD6. The resistor limits the current to a safe level.
+  * **RGB LED Strip** — the output actuator. The strip has a common anode (+5V) and three separate cathode lines (R, G, B). All three channels receive the same PWM duty cycle, producing white light at variable brightness.
+  * **External Power Supply (5V)** — powers the RGB LED strip. GND of the external supply is connected to the MC GND.
   * **Potentiometer** — used in Manual Mode as a variable voltage divider. The wiper voltage is read on ADC0 (PC0) and mapped to a PWM duty cycle.
   * **Photoresistor + Pull-down Resistor** — used in Automatic Mode. The LDR and resistor form a voltage divider; the midpoint is read on ADC1 (PC1). Lower ambient light -> lower voltage -> higher duty cycle -> brighter LED.
   * **16×2 LCD with I2C adaptor** — displays the current brightness percentage and the active mode. Communicates with the MCU via I2C.
   * **User Button (onboard)** — toggles between Manual and Automatic modes. Connected to pin PB7 on the Xplained Mini board.
-  * **Breadboard** — hosts all discrete components (LED, resistors, potentiometer, LDR) and inter-module wiring.
 ===== Hardware Design =====
+==== Bill of Materials ====
+^ # ^ Component ^ Value / Model ^ Qty ^ Notes ^
+| 1 | ATmega328P Xplained Mini | Microchip | 1 | MCU development board |
+| 2 | RGB LED Strip | 5V, 15 LEDs, common anode | 1 | Output lamp |
+| 3 | NPN Transistor | 2N2222 | 3 | Low-side switch for each RGB channel |
+| 4 | Resistor | 1 kΩ | 3 | Base current limiter for 2N2222 |
+| 5 | Resistor | 220 Ω | 1 | LED current limiter |
+| 6 | Resistor | 10 kΩ | 1 | LDR voltage divider pull-down |
+| 7 | Potentiometer | 10 kΩ, linear | 1 | Manual brightness control |
+| 8 | Photoresistor (LDR) | GL5528 or similar | 1 | Auto mode light sensor |
+| 9 | LCD Display | 16×2, I2C (PCF8574) | 1 | Brightness level display |
+| 10 | Breadboard | 400 point | 1 | Component mounting |
+| 11 | Jumper wires | M-M, F-F | ~20 | Connections |
+| 12 | USB cable | Micro-USB | 1 | Power & programming |
+==== Electrical Schematic ====
+{{:pm:prj2026:vlad.radulescu2901:schema_electrica_v4.png?700|}}
+==== Pin Mapping ====
+^ ATmega328P Pin ^ Arduino Pin ^ Signal      ^ Connected To                    ^
+| PD6 (OC0A)    | D6          | PWM RED  | R5 (1kΩ) → Base T1 (2N2222, R channel) |
+| PD5 (OC0B)    | D5          | PWM Green  | R6 (1kΩ) → Base T2 (2N2222, G channel) |
+| PD3 (OC0C)    | D3          | PWM Blue  | R7 (1kΩ) → Base T3 (2N2222, B channel)      |
+| PC0 (ADC0)    | A0          | ADC input   | Potentiometer wiper             |
+| PC1 (ADC1)    | A1          | ADC input   | LDR voltage divider midpoint    |
+| PC4 (SDA)     | A4          | I2C SDA     | LCD SDA                         |
+| PC5 (SCL)     | A5          | I2C SCL     | LCD SCL                         |
+| PB7           | D7          | GPIO input  | Onboard button     |
+| VCC           | 5V          | 5V          | VCC potentiometer, VCC LCD, VCC LDR |
+| GND           | GND         | GND         | GND for all components + external power source |
+===== Software Design =====
+TODO
+===== Results Obtained =====
+TODO
+===== Conclusions =====
+TODO
+===== Journal =====
+TODO
+===== Resources =====
+TODO