Voltmeter and Ammeter

Hardware Development
: Power Supply Circuit:
A relatively stable 5V voltage is provided to the circuit using an SE8552K2-HF, and a series diode is used for reverse
polarity protection. Voltage Sampling Circuit:
The reference voltage used is 1.5V, and the voltage range of this project is calculated to be 0-30V and 0-5V. Data is read through an ADC, and the voltage of the voltage divider resistor is calculated by comparing it with the reference voltage. The voltage measurement is calculated based on the resistance relationship between the two resistors.
Current Sampling Circuit
: Similar to voltage sampling, the voltage is sampled using an ADC, and the obtained value is compared with the 1.5V reference voltage to obtain the voltage of R0, thereby calculating the current in the circuit. Voltage
and Current Calibration Circuit
: The voltage and current meters are calibrated by rotating potentiometers JP1 or JP2 to change their resistance values, thereby changing the input voltage or current. An external multimeter can then be connected to calibrate the sampling circuit.
Software Development
: Since the author is not familiar with Keil software development, the software development of this project mainly refers to the example program of Experiment 9 in the training camp, and only the error messages have been modified. The project code can be found in the attached
physical diagram.