Voltage and current meters

The CW32, developed by JLCPCB in collaboration with Wuhan Xinyuan Semiconductor, features a Cortex-M0 core with
a maximum clock speed of 64MHz. It boasts 8K of RAM and 64K of FLASH chips with a wide operating voltage range of 1.65V-5.5V, meaning it
can operate at higher voltages.
Another often overlooked feature is its 8KV electrostatic discharge (ESD) protection, a
feature rarely seen in other MCUs, allowing it to operate in more demanding environments. It also features a 12-bit ADC (some MCUs advertise 12-bit but are actually 10-bit enhanced).
The CW32 can be widely used in smart home, industrial control, and IoT fields
, making it a suitable entry-level board for beginners learning MCUs
. The CW32's ecosystem is very user-friendly; all information about the CW32 can be found on the official website,
including example programs, application solutions, schematics, and packages, significantly lowering the development threshold and improving efficiency for engineers.
Without further ado, let's begin the explanation of this project.
The hardware
uses a DC power input and a single-plug diode. The DC power input is typically 12V, so
the diode's voltage drop is negligible and it also provides reverse connection protection (since DC power is used, reverse connection is generally not an issue). For
the LDO circuit and button
circuit
, pull-up resistors and capacitors are not required for filtering; the MCU's internal pull-up resistors are sufficient. In the
measurement circuit,
a proper allocation of the R4 and R12 resistor ratio can increase the measurement voltage range (simply increase the value of R4).
The calibration circuit
 
is the remaining simple circuit and will not be elaborated upon further. The software will be uploaded later. (Logo: This
is
 
my first time publishing a work on this open-source platform; there may be formatting and layout issues, so I will revise it later.)