PCBA scheme design - kitchen voice scale chip scheme

An electronic scale, as the name suggests, is a tool used to accurately measure the weight of an object.Electronic scales are generally made of ABS or AAS plastic and stainless steel.And electronic scales are just a big category. There are kitchen scales for weighing 5kg of kitchen fruit and ingredients, jewelry pocket scales for measuring high-precision gold jewelry with a range of 500g, and body weights for measuring body weight and body fat with a range of 180kg.Fat scale.For these scales, users will also require Bluetooth or WiFi functions if necessary, so that users can record and browse the data of each measurement on their mobile phones.

Today, I take the time to introduce a kitchen electronic scale solution with a 5kg range LCD display.

Introduction to the specifications of the kitchen electronic scale PCBA scheme:

Power supply: 3V

Low power detection: 2.4±0.2V, if it is lower than 2.4V, it will display Lo and turn off after 2 seconds

Power-on and power-on: full display for 2-3 seconds after power-on

OnOffKey boot: full display for 2-3 seconds when booting

Boot-to-zero range: ≤1000g, if it is greater than 1000g, it will display OutZ

Boot time to zero: ≤ 10 seconds, if more than 10 seconds, it will display UnSt

Unit conversion order: g-kg-oz-lb

Graduation: 1g/0.001kg/0.05oz/0.002lb; default g;

Minimum display: 2g

Communication: Bluetooth

Voice prompts

Capacity: 5kg

Overload: +200g, showing EEEEE

Negative weight: -2g, display "-" symbol and weight value

Peeling range: <750g, ≥750g display Tare symbol

Shutdown time: 120±10 seconds

OnOff/Tare switch key, peel key: short press to turn on after power off, short press to peel after power on, long press for about 3 seconds to turn off

Unit key: After the power is reset to zero, short press the unit to convert

Calibration: Press the ON/OFF key (three short and one long) to enter the internal code when the internal code is fully displayed, short press the ON/OFF key after the internal code is stable, flash 2000G, put 2000G weight, after stable, flash 5000G, put5000G weight, after stable, LCD will display PASS and return to weighing mode.

The above is an introduction to the specifications of the electronic scale PCBA solution. It is simple and clear, but engineers need to constantly test during development. If there is a problem with the product during the testing stage, it needs to be reported to the software and hardware engineers to solve. Finally, let's learn about the electronic scale.The working principle of the scheme: During weighing, the metal frame of the electronic scale is deformed by force, and the metal wire on the patch is also stretched or shortened, and the resistance of the metal wire changes accordingly.Weighing data.The electrical parameters obtained by the shape of the metal wire are driven by the digital tube to display the numbers after the amplification circuit, the zero-adjustment circuit, the analog-to-digital conversion, and the decoding circuit.