Based on LCSC Diwenxing CW32 digital voltage and current meter

This schematic design explains
the software used.
Since I don't know how to write software, I used the software provided by juminut, and I would like to express my gratitude.
A pre-compiled hex file is attached at the bottom. It can be directly burned.
If you want to learn the code, the attached file (project.zip) contains the Keil software source code.
Five working modes are defined. The K1 key is used to switch display modes. The K2 key sets the parameter value for the corresponding mode and saves it to FLASH. The K3 key returns to mode 0.
Mode 0: Displays normal voltage and current values ​​(the upper row of the digital tube displays the voltage value in .V or .V automatically switches,
the lower row displays the current value in _.**A). Mode 1: 5V voltage calibration setting. The upper row of the digital tube displays 5.05. The lower row displays the current voltage value in _.V or ._V. In this mode, the multimeter should be set to 5.00V to measure the measured bit. After pressing the K2 key, the current value is calibrated to 5V.
Mode 2: 15V voltage calibration setting. The upper row of the digital tube displays 5.15. The next row displays the current voltage value as _.V or ._V. In this mode, the multimeter should be set to 15.0V when measuring the measured part. Pressing the K2 key will calibrate the current value to 15V.
Mode 3: Current 0.5A calibration setting. The upper row of the digital display shows A.0.5. The next row displays the current current value as _.**A. Pressing the K2 key will calibrate the current value to 0.5A.
Mode 4: Current 1.5A calibration setting. The upper row of the digital display shows A.1.5. The next row displays the current current value as *.**A. Pressing the K2 key will calibrate the current value to 1.5A.
Learning video: https://www.bilibili.com/video/BV1Fw4m1C7db/?spm_id_from=333.788&vd_source=66ea5d947e141827003216742d914809
Software author link: https://oshwhub.com/juminut/voltage-ammeter-7347744a