Powering Gravity Sensors (SENXXXX) with ESP32-S3: 3.3V Pin Stability/Current Limits?
Nick.Bender 2025-10-27 19:16:59 305 Views2 Replies Hey DFRobot community,
I'm working on a remote, battery-powered IoT weather station using an ESP32-S3 board and two Gravity sensors (specifically the SEN0368 Temperature/Humidity and a generic SEN0xxxx Gas Sensor).
I was planning to power both sensors directly from the 3.3V output pin on the ESP32-S3 to save power and keep the wiring simple.
My precise question is: What is the typical stable current limit (in mA) I can safely draw from the 3.3V pin of a standard FireBeetle or similar DFRobot ESP32-S3 controller before I risk voltage ripple or component instability?
I know the general rule is about 50mA, but since the gas sensor might have short current spikes, I'd like to confirm the real-world limit based on your experience with these DFRobot boards before I add a dedicated LDO.
Thanks for any insights!
Hey Nick,
From practical experience with FireBeetle ESP32 boards, the 3.3V pin is usually backed by an onboard LDO that’s theoretically capable of a few hundred mA, but that doesn’t mean it’s stable at those levels—especially for sensor loads. In real-world use, staying around 40–60 mA continuous is a good rule of thumb if you want to avoid voltage dips, noise, or Wi-Fi-related brownouts.
Douglas.Duncan Gas sensors are notorious for startup and sampling spikes, so you may see resets or flaky readings over time. For a battery-powered weather station, I’d strongly recommend either a dedicated LDO with good transient response or switching the gas sensor’s power via a MOSFET so it’s only on when needed. It’ll save headaches—and battery life—down the line.
Hope it help!
