“The scale is a combination of science and engineering, the amount of mechanical pressure on the load cell produces some signals, the signal amplifies with HX711 and then it gets read by Arduino. for better reading, making the noiseless environment free of vibration, air circulation and rapid temperature tolerance is necessary.
I made this Scale in a way to calibrate itself automatically with 300g precise weight and also show working temperature for a better reading result. However, loadcells have some basic drawbacks like drifting its offsets which is inevitable anyway. by the way, keep it in mind that the precision and time of reading are against each other, as much as the precision increases, the time consumed to read the signal would increase too.
I used some parts and box of a dead scale, you can make it simply by yourself.
1- Arduino nano x1
2- Jumper Wires, so many
3- Soldering tools, as required
4- 470 Ohm Resistors x2
5- 10K Resistors x1
6- 5 kg Load cell x1
7- load cell holder, some screws, and skills
8- HX711 Amplifier x1
9- NTC 10K x1
10- 9V, 500mA DC power source x1
11- Arduino nano USB cable x1
12- LCD 16X2 x1
13- I2C Module x1
14- push buttons x2”