dimswitch

SinricPro DimSwitch Example

Control a dimmable light with voice commands - brightness control with PWM.

Hardware

• ESP32 board
• High-power LED or LED strip
• MOSFET or LED driver (e.g., IRF520, IRLZ44N)
• Current-limiting resistor (if using single LED)
• External power supply (12V for LED strip)

Wiring

For LED Strip (12V)

ESP32 GPIO25      → MOSFET Gate
MOSFET Source     → GND (common ground with ESP32)
MOSFET Drain      → LED Strip Negative (-)
LED Strip (+)     → 12V Power Supply (+)
Power Supply (-)  → GND (common ground)

For Single High-Power LED

ESP32 GPIO25      → MOSFET Gate
MOSFET Source     → GND
MOSFET Drain      → LED Cathode (-)
LED Anode (+)     → Current Resistor → 12V+

Features

• Dimmable brightness 0-100%
• PWM-based LED control (5kHz)
• Brightness adjustment (increase/decrease)
• Physical button for on/off toggle
• Smooth dimming transitions
• Auto turn-on when brightness is set

Voice Commands

• "Alexa, turn on the light"
• "Alexa, turn off the light"
• "Alexa, dim the light"
• "Alexa, brighten the light"
• "Alexa, set light to 50 percent"
• "Alexa, set light brightness to 75"

Build

cd examples/dimswitch
idf.py build flash monitor

Configuration

Edit main/dimswitch_example.c - update WiFi and SinricPro credentials.

For different GPIO or PWM settings, modify:

#define LED_GPIO                (25)
#define LED_FREQUENCY           (5000)  /* 5 kHz */
#define BUTTON_GPIO             (0)

Physical Button

Press BOOT button (GPIO0) to toggle light on/off. The state is sent to SinricPro.

DimSwitch vs Light Device

• DimSwitch: Simple brightness control only (this example)
• Light: Adds color control, color temperature (see examples/light)

Choose DimSwitch for:

• Single-color LED strips
• Dimmable white bulbs
• Simple lamp control

Choose Light for:

• RGB LED strips
• Color-changing bulbs
• Color temperature control

Hardware Notes

1. PWM Frequency: 5kHz is flicker-free for most LEDs
2. MOSFET: Use logic-level MOSFETs (gate threshold < 3.3V)
3. Heat Sinking: Use heatsink for high-power applications
4. Current Limit: Calculate resistor: R = (Vsupply - Vled) / Iled
5. Common Ground: ESP32 and LED power supply must share GND

Recommended MOSFETs

• IRF520: Good for 5-10A loads
• IRLZ44N: Logic-level, handles up to 47A
• IRL540N: Logic-level, handles up to 33A

Safety

• Never exceed MOSFET current rating
• Add proper heat dissipation for continuous operation
• Use appropriate gauge wire for high currents
• Fuse the power supply for protection