Voltage and Ammeter Training Camp - Mu Yueguang - 07/16

I. Function Introduction
1. Voltage Measurement
Range: 0~34.5V (Theoretical Value)
2. Current Measurement
Range: 0~3A
Since the current sampling resistor is 0.1Ω/1W, according to the power formula P = I^2 * R; I ≈ 3.3333; rounded down, the measurement range is 0~3A.
3. Button Functions
From left to right, these are K1, K2, and K3 buttons.
K1 Function: Cycles through the interface.
K2 Function: Saves calibration values; calibrates voltage and current and saves calibration values ​​during the calibration interface.
K3 Function: Returns to the voltage and current measurement interface.
4.
When pressing K1, the upper digital display will show either the calibration voltage or current, and the calibrated voltage and current values.
The lower digital display will show the currently measured voltage or current value.
U represents the calibration voltage. 1.0 indicates the current calibration voltage is 1.0V.
1.88 indicates the current measured voltage is 1.88V.
C represents the calibration current. 0.5 indicates the current calibration current is 0.5A.
0.00 indicates that the current measured current is 0A.
II. Hardware Introduction
Hardware selection can be referred to the official example program; for brevity, further details are omitted.
Difference from the official example program (improvement):
The power supply circuit VP network number is connected to the positive terminal of the switching diode.
III. Hardware Optimization
① A self-locking switch can be added to the power supply circuit, located after the network number VP and before the switching diode.
② The voltage and current measurement terminals can be replaced with rubber sockets (same as the external voltage and current verification interface).
③ The expansion board LED can be connected to another GPIO port (the core board LED is already connected to PC13).