ammeter

Hardware circuit design: The main control uses STC8G1K08-TSSOP20 microcontroller, which costs 1.5 yuan. The microcontroller io directly drives the 4-bit 0.28-inch digital tube and uses the 4.1k pull-up resistor integrated inside the microcontroller to limit the current.
The current collection uses INA180A3 with an amplification factor of 100 to minimize the impact of current collection on the load. The current range can be modified by adjusting the size and amplification factor of the sampling resistor.
The power supply uses a 7805, wide voltage input, simplified circuit design, input anti-reverse
 
function design:
the board has a button and an LED light, the button is used to switch the content displayed by the digital tube, and can be switched to voltage, current, and power. . LEDs can be dimmed by PWM and are mainly used to dynamically display current fluctuations.
The numerical display refresh rate of the digital tube is 5hz, and the measurement rate of the host computer is 10khz.
Voltage measurement range: 7-30v
Voltage measurement range: 0-30v (independent power supply)
Current measurement range: 0-5A
Adjustable sampling resistance and amplification factor, and independent power supply, used to collect current fluctuations of low-power devices and analyze loads Working status of
 
the host computer design:
The host computer uses free vofa+ display, uses serial port communication, and customizes the communication protocol. It can transmit voltage and current values ​​at a frequency of 10khz under the condition of a serial port baud rate of 2000000. Try synchronous display on the host computer, which can easily adjust the zoom size. The data recording time is affected by the computer configuration, and can generally reach tens of millions of frames of data.
Use a universal USB to serial cable to connect to the serial port of the module. Open the vofa+ host computer, select the corresponding serial port, baud rate 2000000, data engine: UintData, you can see real-time data and waveform
 
 
details on the right: https://blog.csdn.net/Dommsday/article/details/ Source code project of 126928175
microcontroller: https://gitee.com/epoko/voltmeter
PC official website download: https://www.vofa.plus