Voltmeter and Ammeter

PDF_STC32G12K128 Mini Development Board.zip

Altium_STC32G12K128 small development board.zip

PADS_STC32G12K128 small development board.zip

BOM_STC32G12K128 Mini Development Board.xlsx

92627

CW32-Voltage and Current Meter

Voltage and current meters based on LCSC development board-CW32F030

Video Link:
Bilibili Video -- Function Demonstration and Introduction
Description
This project is a voltage and current meter based on CW32F030, with voltage and current measurement functions.
Approximate voltage measurement range: 0-30V (can be simulated for testing)
Approximate current measurement range: 0-3A (can be simulated for testing)
Photos of the finished product are shown below. This was
my first time using 3D printing and panel printing, and there were some minor mishaps, but thankfully it didn't affect the overall result much.
All the components used this time are plug-in type. Below are pictures of my soldering process. A family photo
of all the components connected
. No! A few plug-ins are still missing
because they haven't arrived. The design is quite casual, and the color silkscreen function is only reserved for the LCSC development board and Sinyuan Semiconductor.
The PCB is basically based on the official design, including the placement, layout, and routing.
The hardware power supply uses DC-DC input voltage of 5V-12V. Now
for the key point: This 32-bit chip has: a 12-bit high-speed ADC that can reach ±1.0LSB INL 11.3ENOB, and multiple Vref reference voltages. The STM32 we commonly use only supports VDD=Vref. This system uses a built-in 1.5V reference voltage, which can be configured via the program. However
, a mistake was made in component procurement; common-cathode digital tubes were intended, but common-anode ones were mistakenly purchased. I mentioned that the digital tubes were malfunctioning after downloading the program, and after investigation, the problem turned out to be the incorrect procurement. The following is a modified part of the program for a common anode digital tube:
/* Common anode digital tube encoding table:
0xc0 0xf9 0xa4 0xb0 0x99 0x92 0x82 0xf8 0x80 0x90
0 1 2 3 4 5 6 7 8 9
0x40 0x79 0x24 0x30 0x19 0x12 0x02 0x78 0x00 0x60
0. 1. 2. 3. 4. 5. 6. 7. 8. 9.
0x3f 0xbf
0 0 1 1 1 1 1 1 1 1011 1111
dp GFEDCBA
*/
uint8_t Seg_Table[21] = {0xc0, 0xf9, 0xa4, 0xb0, 0x99, 0x92, 0x82, 0xf8, 0x80, 0x90,
0x40, 0x79, 0x24, 0x30, 0x19, 0x12, 0x02, 0x78, 0x00, 0x60,0x08};// 0x08:A.
// Common terminal settings:
/**
* @brief Close all common terminals
*
*/
void Close_Com(void)
{
GPIO_WritePin(CW_GPIOA,GPIO_PIN_8,GPIO_Pin_RESET);
GPIO_WritePin(CW_GPIOB,GPIO_PIN_3,GPIO_Pin_RESET);
GPIO_WritePin(CW_GPIOB,GPIO_PIN_4,GPIO_Pin_RESET);
GPIO_WritePin(CW_GPIOA,GPIO_PIN_11,GPIO_Pin_RESET);
GPIO_WritePin(CW_GPIOA,GPIO_PIN_12,GPIO_Pin_RESET);
GPIO_WritePin(CW_GPIOA,GPIO_PIN_15,GPIO_Pin_RESET);
} // Modification switch(Pos)
in Seg_Dis function { case 0: GPIO_WritePin(CW_GPIOA,GPIO_PIN_8,GPIO_Pin_SET); //PA8,COM1 break; case 1: GPIO_WritePin(CW_GPIOA,GPIO_PIN_11,GPIO_Pin_SET); //PA9,COM2 break; case 2: GPIO_WritePin(CW_GPIOA,GPIO_PIN_12,GPIO_Pin_SET); //PA10,COM3 break; case 3: GPIO_WritePin(CW_GPIOA,GPIO_PIN_15,GPIO_Pin_SET); //PA11,COM4 break; case 4: GPIO_WritePin(CW_GPIOB,GPIO_PIN_3,GPIO_Pin_SET); //PA12,COM5 break; case 5: GPIO_WritePin(CW_GPIOB,GPIO_PIN_4,GPIO_Pin_SET); //PA15,COM6 break; default: break; } Just change all of them to common cathode and it's OK.
























Actually, understanding digital tube displays is quite simple. I'll paste some notes from my school days. Back then, I used I/O ports to drive transistors, and the transistors drove the digital tubes. I also used the STM32's PB4 pin, which needs to be configured for multiplexing to be used as a regular GPIO.
The program is fully commented to make it easier for beginners to understand. Please download the attached program for reference.
That's about it. I wish myself and everyone else continued success!

Voltage and Ammeter Project.zip

Demo video.mp4

PDF_CW32-Voltage and Current Meter.zip

Altium_CW32-Voltage and Current Meter.zip

PADS_CW32-Voltage and Current Meter.zip

BOM_CW32-Voltage and Current Meter.xlsx

92629

CW32 Voltmeter and Ammeter Training Camp Project

A CW32 voltage and current meter replica based on the CW32 voltage and current meter training camp.

Project Introduction: This project
describes a miniaturized (all-surface-mount design) integrated voltage and current meter based on the CW32 voltmeter and ammeter training program. We hope this successful experience will provide a unique perspective for enthusiasts.
1. The power supply circuit
uses a common 3.3V linear regulated power supply to power the chip and digital display.
2. Advantages of CW32

: Wide operating temperature range: -40~105℃;
Wide operating voltage: 1.65V~5.5V (STM32 only supports 3.3V systems)
; Strong anti-interference: HBM ESD 8KV; All ESD reliability reaches the highest international standard level (STM32 ESD 2KV)
; Project focus - Better ADC: 12-bit high-speed ADC, achieving ±1.0LSB INL 11.3ENOB; Multiple Vref reference voltages... (STM32 only supports VDD=Vref);
Stable and reliable eFLASH technology. (Flash0 pending)

3. The voltage sampling circuit
uses a voltage divider circuit to achieve high voltage acquisition. It is designed to acquire up to 100V, but the current configuration allows for acquisition of 0-30V.
4. The current sampling circuit
uses a low-side current sampling circuit for current detection. The low-side of the sampling circuit shares a common ground with the development board's meter interface .
5. The digital tube driver
uses a digital tube as the display unit.
6. Indicator lights:
An additional power indicator and an IO working indicator light are designed.
7. Button circuit.
8. TL431 circuit design for voltage measurement calibration:
An additional TL431 circuit is added to provide a 2.5V reference voltage, which can be used to provide an external voltage reference for calibrating the AD converter.
Voltage Testing:
1. 5V charger voltage test (error approximately 0.3V)
2. Battery voltage measurement test (error approximately 0.4V)