copilot

tinoaja07

copilot

• Adapter Module: Converts 220V AC to 5V DC.
• Charger Module: Manages the charging of the 18650 battery.

tinoaja07

copilot

• DC Lamp (12W): It's connected to the output of $Q1$. Ensure that the transistor can handle the increased current demand.
• Power Considerations: Make sure your power supply and battery can handle the total load of the LEDs and the DC lamp.

tinoaja07

copilot

• 18650 Battery: Powers the entire system.
• Battery Charger Module (e.g., TP4056): Manages the charging of the battery from either USB or the adapter.
• 12W DC Lamp: Main lighting component.
• On/Off Switch: Controls the power to the DC lamp from the battery.

tinoaja07

copilot

Cpp
#include 

const int batteryPin = 34; // Analog pin to measure battery voltage
const float maxVoltage = 4.2; // Maximum voltage for a fully charged 18650
const float minVoltage = 3.0; // Minimum safe voltage
const float dischargeThreshold = 3.6; // Voltage corresponding to ~50% discharge
const int chargerCtrlPin = 26; // Digital pin to enable/disable charger

void setup() {
  Serial.begin(115200);
  pinMode(chargerCtrlPin, OUTPUT);
  digitalWrite(chargerCtrlPin, LOW); // Start with charging off
}

void loop() {
  float batteryVoltage = getBatteryVoltage();
  Serial.println("Battery Voltage: " + String(batteryVoltage) + " V");

  if (batteryVoltage < dischargeThreshold) {
    startCharging();
  } else {
    stopCharging();
  }

  delay(60000); // Check every minute
}

float getBatteryVoltage() {
  int rawValue = analogRead(batteryPin);
  float voltage = rawValue * (maxVoltage / 4095.0); // Convert to voltage
  return voltage;
}

void startCharging() {
  digitalWrite(chargerCtrlPin, HIGH); // Activate charger
  Serial.println("Charging enabled");
}

void stopCharging() {
  digitalWrite(chargerCtrlPin, LOW); // Deactivate charger
  Serial.println("Charging disabled");
}

• Battery Monitoring: Use a voltage divider to scale down the battery voltage to a range the ESP32 can measure (0-3.6V for safety).
• Charger Control: Use a digital pin on the ESP32 to control the charge enable pin on the charger module.
• ESP32 Analog Pin: Use an appropriate pin to read the scaled battery voltage.

• Voltage Divider: Necessary to safely measure battery voltage without exceeding the ESP32's input limits.
• Charger Module: Ensure the charger module has a controllable enable/disable pin.
• Voltage Calibration: Calibrate the voltage reading depending on the actual resistors used in the voltage divider.

tinoaja07

copilot

• ESP32-WROOM-32:
  • Functions: Monitors the battery voltage and controls the charger.
  • Connections:
    • Connect the battery voltage (via a voltage divider) to an analog input on the ESP32 to read the battery level.
    • Use a digital output pin to control the charger module's enable/disable function.
• Voltage Divider:
  • Purpose: Scales down the battery voltage $3V$ to $4.2V$ to a safe level $0V$ to $\sim3.3V$ for the ESP32's analog input.
  • Connections: Connects between the battery and an analog input on the ESP32.
• 18650 Battery:
  • Function: Powers the system and is monitored for charge/discharge levels.
• Battery Charger Module (e.g., TP4056):
  • Control: Controlled by the ESP32 to start or stop charging based on the battery level.
• 12W DC Lamp & Switch:
  • Function: The main light is manually operated by the switch.

• Voltage Monitoring: The ESP32 continuously monitors the battery's voltage through the voltage divider.
• Automated Charging: When the voltage drops to approximately $3.6V$ (50% discharge), the ESP32 activates the charger module.
• Manual Lamp Control: The lamp is controlled through a manual switch connected in series with the battery.

tinoaja07

copilot

1. ESP32-WROOM-32
   • Analog Input (A0): Connect to the middle of the voltage divider to read the battery voltage.
   • Digital Output (D13): Connect to the control pin on the charger module to enable/disable charging.
2. Voltage Divider
   • Resistors R3 and R4: Form a voltage divider to step down the battery voltage for safe analog reading.
   • Connect one end of $R3$ to the Battery positive terminal.
   • Connect the junction of $R3$ and $R4$ to the ESP32 analog input.
   • Connect the other end of $R4$ to Ground.
3. Battery (18650)
   • Connect the positive terminal to $R3$ (as part of the voltage divider) and to the Switch and Charger input.
   • Connect the negative terminal to Ground.
4. Battery Charger Module (e.g., TP4056)
   • Connect the charger's input to the output of the Adapter or USB.
   • Connect the charger's output to the battery.
   • Connect the control pin of the charger to the ESP32 digital output.
5. 12W DC Lamp
   • Connect one end to the On/Off Switch.
   • Connect the other end of the Switch to the battery positive terminal.
6. Switch
   • Connect in series between the lamp and the battery to control the power.
7. Adapter Module (220V AC to 5V DC)
   • Connect its DC output to the input of the Charger.

• The ESP32 provides intelligence to monitor the battery voltage and control the charging process.
• The Voltage Divider safely scales the battery voltage for analog reading.
• The Battery powers the 12W DC lamp directly through a manual Switch.
• The Charger Module keeps the battery charged, controlled by the ESP32.
• The Adapter provides power to the charger from an AC source.

tinoaja07

copilot

• Formula for Voltage Divider: $ V_{\text{out}} = V_{\text{in}} \times \frac{R4}{R3 + R4} $

• Maximum Battery Voltage is 4.2V.
• ESP32's maximum ADC reference voltage is approximately 3.3V.
• Let's select $ R4 = 10k , \Omega $ as a commonly used value.

Python
# Constants for calculation
R4 = 10000  # in Ohms
Vin_max = 4.2  # in Volts
Vout_max = 3.3  # in Volts

# Calculate R3
R3 = (Vin_max * R4 / Vout_max) - R4
R3

• $ R3 = 2.7k , \Omega$ (a standard resistor value)
• $ R4 = 10k , \Omega$