How to use a circuit diagram template.
- 01Pick your ESP32 board and current sensor
Select the ESP32 variant (e.g., DevKit V1) and a sensor that matches your load type—INA219 for DC, ACS712 for AC, or a current transformer for higher currents.
- 02Wire the sensor to the ESP32
Connect the sensor’s output to the appropriate ESP32 pins. For I2C sensors, use GPIO21 (SDA) and GPIO22 (SCL). Analog sensors like ACS712 go to a 12‑bit ADC pin (e.g., GPIO34).
- 03Add a shunt or load connection
Integrate a shunt resistor if using a high‑side current sensor, and add screw terminals or a plug for the load. Ensure the sensor is in series with the load.
- 04Include power supply and protection
Power the ESP32 (5V via USB or Vin) and the sensor if needed. Add a TVS diode and a fuse on the input for overvoltage/overcurrent protection.
- 05Export and share your schematic
Once your circuit is complete, export it as SVG or PNG. Embed it in your project documentation or share it directly with your team.
Questions about circuit diagram templates
Which current sensor works best for ESP32 load monitoring?
It depends on your load. For low‑current DC loads (up to 3.2A), the INA219 is a great choice—it connects via I2C and gives direct power readings. For AC loads up to 30A, the ACS712 is popular and easy to wire. For higher currents, use a current transformer (CT) with a burden resistor and an op‑amp.
Can I monitor 3‑phase loads with an ESP32?
Yes, you can sample three current channels using three analog input pins and a suitable multiplexing scheme or by using three individual CTs. The ESP32’s ADC runs fast enough for basic three‑phase current monitoring, but for precise power calculations, consider an external ADC like the ADS1115.
How do I measure AC current with an ESP32?
Use a non‑invasive current transformer (CT) or a Hall‑effect sensor like the ACS712. The ESP32’s ADC reads the instantaneous voltage, and you calculate root‑mean‑square (RMS) current in firmware. Libraries like EmonLib can simplify the math.
What is the maximum load current an ESP32 can monitor?
The ESP32 itself can’t handle large currents—the sensor limits the maximum. With a CT, you can measure hundreds of amps. For direct‑connection sensors like the ACS712‑30A, the limit is 30A. Always ensure the wiring and board layout can handle the current safely.
Do I need an external ADC for accurate load monitoring?
The ESP32’s built‑in 12‑bit ADC works well for many hobbyist projects, but it is non‑linear at low voltages. For precise current measurements or when using a wide range, an external ADC like the ADS1115 (16‑bit, I2C) gives smoother results and better resolution.