ESP32 Relay Schematic

Thought for 4 sec

I couldn’t modify the schematic in this session. The project remains empty with 0 components and 0 nets.

The corrected design direction is:

Use the LM2596 for 12 V → 5 V, primarily for the relay coils.
Add a dedicated 5 V → 3.3 V regulator for the ESP32 and PCF8575 devices.
Use 1 kΩ series base resistors and 10 kΩ base-to-ground pull-downs for all 14 BC547 drivers.
Add a flyback diode across every relay coil.
Pull SDA and SCL up to 3.3 V with 4.7 kΩ resistors.
Strap each PCF8575 to a unique I²C address and add local decoupling.
Add LM2596 input/output bulk and ceramic capacitors, plus ESP32 rail bulk capacitance.

One further design constraint remains: a “30-pin ESP32-WROOM” usually means a 30-pin development board rather than the bare ESP32-WROOM module, so the exact board/module footprint must be confirmed before capture.

Execution stopped because your ACUs ran out.

mkamau225

The ESP32 DevKit V1 30-pin development board is being used, not the bare ESP32-WROOM module. The board has an onboard AMS1117-3.3 regulator. VIN accepts 5V from the LM2596. The 3.3V pin powers the PCF8575 chips. No additional 3.3V regulator needed. Change BC547 base resistors to 10kΩ pull-downs to GND. Add 1N4007 flyback diodes across all relay coils. Continue generating the schematic

Thought for 4 sec

flux

The design requirements are now resolved:

ESP32 DevKit V1 30-pin board powered with 5 V at VIN
DevKit onboard AMS1117-3.3 powers the three PCF8575 ICs from its 3V3 pin
Fourteen direct-GPIO relay drivers, each using:
- BC547
- 1 kΩ GPIO-to-base resistor
- 10 kΩ base-to-GND pull-down
- 1N4007 flyback diode across the relay coil
PCF8575 I²C bus on GPIO21/GPIO22 with 4.7 kΩ pull-ups to 3.3 V
12 V input and LM2596 5 V buck stage
Local decoupling for the ESP32 supply, each PCF8575, and the power rails

No components or nets were added, so the project remains empty. Execution stopped because your ACUs ran out.

No schematic yet

Talk to Flux to get started.