Design of Weight Health Management System Based on WeChat Platform
With the advancement of electronic weighing technology, electronic scales have gradually replaced traditional weight measurement devices. These modern scales offer user-friendly operation, accurate readings, compact design, fast measurement speed, and easy-to-read displays, making them widely adopted in commercial trade, hospitals, schools, and enterprises. As manufacturing techniques improve, electronic scales are becoming lighter and more portable, aligning with people's growing interest in monitoring their physical appearance. As a result, most households now own an electronic scale. Additionally, with the rise of the Internet of Things (IoT) era and the development of WeChat technology, IoT systems are increasingly leveraging the WeChat platform. This article presents a weight management system built on the WeChat platform. Not only does it measure weight, but it also helps users track their weight changes over time. By integrating WeChat, the system offers a more intuitive and interactive user experience, enhancing both usability and intelligence.
**1. System Overall Structural Design**
The system is centered around the STM32 single-chip microcontroller. The hardware component uses a differential full-bridge circuit based on resistance strain gauges, while the A/D conversion section employs the HX711 chip. Beyond basic weight measurement, the system introduces data storage and analysis features through the WeChat platform, WiFi, and the Cloud platform. It allows users to store and analyze their weight data, with results returned via WeChat. Users can also remotely control the electronic scale through the WeChat interface.
*Figure 1: System overall structure block diagram*
**2. Load Cell Design**
**2.1 Resistance Strain Gauge Sensor**
The fundamental function of the weight management system is to measure body weight. Therefore, the load cell is one of the most critical components, as its performance directly affects the accuracy and stability of the electronic scale. To ensure precision, the system utilizes a differential full-bridge circuit composed of four identical resistance strain gauges. As shown in Figure 2, when no force is applied, the output voltage of the unbalanced bridge is:
When the bridge is balanced, and assuming R1 = R2 = R3 = R4, and ΔR1 = ΔR2 = ΔR3 = ΔR4 under load, the output voltage U0 becomes linear with ΔR/R. The differential full-bridge configuration reduces errors and provides temperature compensation. The voltage sensitivity is given by SV = E, ensuring stable and accurate measurements.
*Figure 2: Differential full bridge circuit*
15kwh lithium battery,lithium battery 48v 200ah for solar system,lifepo4 battery 48v,48v lifepo4 battery,10kwh lifepo4 battery,48v 100ah lifepo4 battery,48v 200ah lithium ion battery,10kwh lithium battery,51.2v lifepo4 lithium battery
Shenzhen Jiesaiyuan Electricity Co., Ltd. , https://www.gootuenergy.com