❗ The Problem: Power Instability = Inaccurate Readings

Most smart scales use a 3.3V or 5V rail to power components like load cells and amplifiers. However, when running on a 3.7V Li-ion battery, voltage can dip or fluctuate, especially under load. This instability can cause inaccurate weight readings, random resets, or even complete failure of the scale’s microcontroller or ADC (like HX711).

🛠️ The Solution: Regulate & Filter the Power

To keep readings consistent:

• Use a low-dropout (LDO) voltage regulator to convert 3.7V from your Li-ion battery to a clean 3.3V.

• Add filter capacitors—470µF electrolytic and 0.1µF ceramic—close to the HX711 and MCU to reduce ripple and noise.

📦 Practical Example: Battery-Powered Kitchen Scale

A DIY kitchen scale using an HX711 and ESP32 resets when measuring heavy items. After adding an AMS1117-3.3 LDO regulator and filtering caps, the system stabilizes and gives consistent readings—even at low battery levels.

🔢 Sample Calculation: Choosing the Right Regulator

Battery voltage = 3.7V
Required output = 3.3V
Choose an LDO with dropout < 0.4V (like AMS1117)
Current = 100mA
Power = 3.3V × 0.1A = 0.33W

🛒 Product Suggestion – Made in India

🔋 Voltage Regulator Module (3.3V LDO):

🔧 HX711 Load Cell Amplifier:

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