STM32 vs CH55x Cost and Performance Comparison Analysis: No More Hesitation in Embedded Selection

Doing embedded development, choosing a chip is like choosing a partner - there’s no “best”, only “most suitable”.

Recently a friend asked me: “For mass production, should I choose STM32F103 or CH552?” This question seems simple, but actually involves multiple dimensions like cost, performance, development ecosystem, and supply stability. Today I’ll pull out these two classic chips for a thorough comparison to help you make a wise choice.

What Needs to Be Clarified First?

Before starting the comparison, let’s clarify one point: STM32 and CH55x have different positioning. STM32 is a general-purpose MCU with ARM Cortex-M core, while CH55x is WCH’s self-developed 8051 core USB-dedicated MCU. Comparing them is a bit like comparing an SUV with a sedan - it depends on your use case.

Chip Specification Comparison

Specification	STM32F103C8T6	CH552	CH559
Core	ARM Cortex-M3	8051 (WCH enhanced)	8051 (WCH enhanced)
Frequency	72 MHz	24 MHz	24 MHz
Flash	64 KB	32 KB	64 KB
RAM	20 KB	2 KB + 256B	4 KB + 256B
USB	USB FS (Device/Host)	USB 2.0 Device	USB 2.0 Host/Device
ADC	12-bit, 10 channels	10-bit, 8 channels	10-bit, 8 channels
UART	3 USART, 2 UART	2 UART	2 UART
GPIO	37 pins	25 pins	42 pins
Operating Voltage	2.0-3.6V	3.3V	3.3V / 5V (5V tolerant)
Package	LQFP48 / LQFP64	LQFP32 / QFN32	LQFP48
Price (1k+)	¥8-12	¥2.5-3.5	¥4-5

Price Data Source: LCSC March 2026 quotation, batch 1000+ pieces

What Do You Need to Prepare?

If you want to test these two chips, here’s the recommended minimum development system:

Item	Model	Price
STM32 Development Board	Blue Pill (F103C8T6)	¥15
CH552 Development Board	CH552T Minimum System Board	¥12
CH559 Development Board	CH559 Minimum System Board	¥25
USB to TTL Module	CP2102	¥5
Jumper Wires	Male-to-Female	¥8
Total		¥51

Performance Benchmark Comparison

1. GPIO Toggle Speed Test

This is the most basic performance metric, we test with the simplest code:

// STM32F103 (72MHz)
// Using direct register operations
while(1) {
    GPIOC->BSRR = (1<<13);   // Set PC13
    GPIOC->BSRR = (1<<(13+16));  // Reset PC13
}
// Measured: approximately 12 MHz toggle frequency

// CH552 (24MHz)
// Direct P1 port operation
while(1) {
    P1 |= 0x01;  // Set P1.0
    P1 &= ~0x01; // Reset P1.0
}
// Measured: approximately 4 MHz toggle frequency

Conclusion: STM32’s GPIO toggle speed is about 3 times that of CH552, consistent with the frequency difference. But for most control applications (relays, LEDs, motor PWM), CH552’s 4MHz is already more than enough.

2. USB Communication Performance

This is CH55x’s home turf. We test USB Bulk transfer speed:

// CH559 USB Host reading U disk data
// Using simplified version of WCH official CH376 library
UINT16 USB_ReadBulk(PIPE bulk_pipe, PUINT8 buf, UINT16 len) {
    // Actual transfer rate approximately 800 KB/s
    // Limited by USB 1.1 Full Speed (12 Mbps theoretical)
}

Test Results:

• CH559 USB Host reading U disk: approximately 750 KB/s
• STM32F103 USB FS Device: approximately 600 KB/s
• CH552 USB Device (HID): approximately 64 KB/s (limited by HID report size)

Conclusion: CH559 has a natural advantage in USB Host applications; WCH’s USB protocol stack has been optimized over many years with good stability. STM32 requires you to port it yourself or purchase a commercial protocol stack.

3. ADC Sampling Accuracy Comparison

// STM32F103 ADC Configuration (12-bit)
ADC_InitTypeDef ADC_InitStructure;
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = DISABLE;
ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_TRGO;
ADC_Init(ADC1, &ADC_InitStructure);
// Measured ENOB ≈ 10.5 bit

// CH552 ADC Configuration (10-bit)
ADC_CFG = 0x80;  // Enable ADC
ADC_CONTR = 0x85; // 10-bit, channel 5
// Measured ENOB ≈ 8.5 bit

Test Results:

Chip	Nominal Resolution	Actual ENOB	Sampling Rate
STM32F103	12-bit	10.5 bit	1 MSPS
CH552	10-bit	8.5 bit	300 KSPS

Conclusion: STM32’s ADC performance is obviously better, suitable for applications requiring high-precision analog acquisition (such as sensors, audio). CH552 is suitable for simple potentiometer, battery voltage detection scenarios.

Development Experience Comparison

Toolchain Maturity

STM32:

• ✅ Many IDE choices: Keil MDK, IAR, STM32CubeIDE, VSCode + PlatformIO

• ✅ HAL library + LL library + Standard library, choose according to needs

• ✅ STM32CubeMX graphical configuration, automatically generates initialization code

• ✅ Huge community, Stack Overflow has answers for everything

• ❌ Environment configuration relatively complex, beginners easily fall into pitfalls

CH55x:

• ✅ Official provides SDCC compiler + WCHISPTool flashing tool

• ✅ Code is concise, 8051 architecture easy to understand

• ✅ WCH official examples are high quality with detailed comments

• ❌ Few IDE choices (mainly VSCode + plugins)

• ❌ Community relatively small, encountering problems requires studying datasheets yourself

Code Volume Comparison

Implementing the same USB HID keyboard function:

// STM32F103 (using HAL library + USB Middleware)
// Need to configure: clock, GPIO, USB, interrupts, descriptors...
// Total code: approximately 800 lines (including library files)

// CH552 (using WCH official example)
// Main modifications: USB descriptor + key scanning
// Total code: approximately 200 lines (including library files)

Conclusion: CH55x has less code for USB applications; WCH has encapsulated all the complex protocol details.

Cost Analysis (Mass Production Perspective)

Suppose you want to make a USB device, annual production 10k units:

Cost Item	STM32F103 Solution	CH552 Solution
MCU cost	¥9.5	¥2.8
USB-to-TTL chip	¥0.5 (CP2102)	¥0 (built-in USB)
LDO	¥0.3	¥0 (3.3V LDO built-in)
PCB area	20×20mm	15×15mm
Single unit BOM cost	¥10.3	¥2.8
10k unit total cost	¥103,000	¥28,000
Cost savings	-	¥75,000

Conclusion: In USB device applications, CH552 can save approximately 70% of MCU-related costs. For price-sensitive consumer electronics, this is a huge advantage.

Selection Decision Tree

Does your project need USB functionality?
├─ No → Need high performance/multiple peripherals?
│       ├─ Yes → STM32F4/F7/H7 series
│       └─ No → STM32F103 or CH55x (depends on cost)
│
└─ Yes → USB Host or Device?
        ├─ Host (read U disk/connect other USB devices)
        │   └─ CH559 (best cost-performance)
        │
        └─ Device (keyboard/mouse/custom device)
            ├─ Need complex functions (audio/mass storage)
            │   └─ STM32F103/F4
            │
            └─ Simple HID/custom transfer
                └─ CH552 (cost priority) or CH559 (performance priority)

Common Problem Troubleshooting

Problem 1: CH552 program doesn’t run after flashing

• Cause: May be watchdog not disabled or clock configuration error

• Solution:

// Disable watchdog at the very beginning of main()
WDC_CONTR = 0x00;
// Configure system clock to 24MHz
SAFE_MOD = 0x55;
SAFE_MOD = 0xAA;
CLOCK_CFG |= bOSC_EN_XT;  // Enable external crystal

Problem 2: STM32 power consumption higher than expected

• Cause: Unused peripheral clocks not disabled, or GPIO in floating input

• Solution:

// Disable unused peripheral clocks
__HAL_RCC_USART2_CLK_DISABLE();
__HAL_RCC_SPI2_CLK_DISABLE();
// Configure unused GPIO as analog input (lowest power)
GPIO_InitTypeDef GPIO_InitStruct;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

Problem 3: CH559 USB Host cannot recognize device

• Cause: Insufficient power or D+/D- pull-up resistor configuration error

• Solution:

// Ensure VBUS power supply is sufficient (at least 100mA)
// Configure correct USB speed (Full/Low Speed)
USB_CTRL = bUC_HOST_MODE | bUC_LOW_SPEED;  // Low speed device
USB_CTRL = bUC_HOST_MODE;  // Full speed device

Summary

After detailed comparison, we reach the following conclusions:

Reasons to choose STM32F103:

• ✅ Need high performance (72MHz Cortex-M3)

• ✅ Need high-precision ADC (12-bit)

• ✅ Need rich peripherals (multiple USART/SPI/I2C)

• ✅ Project complexity is high, needs mature ecosystem support

• ✅ Not cost-sensitive (or low volume)

Reasons to choose CH55x:

• ✅ USB is core requirement (especially USB Host)

• ✅ Cost-sensitive, needs mass production

• ✅ Functions relatively simple, 8051 performance sufficient

• ✅ Want rapid development, reduce code volume

• ✅ Can accept relatively smaller community

My suggestion: Don’t blindly believe “ARM is definitely better than 8051”. In the USB device segment, CH55x with its extremely high cost-performance and WCH’s many years of accumulated USB protocol stack is a very competitive choice. Three mass production projects I participated in (USB debugger, custom HID controller, U disk data collector) all chose CH55x, with cumulative shipments exceeding 50k units, stability has withstood market testing.

Of course, if your project needs to run FreeRTOS, needs DSP instructions, needs advanced peripherals like Ethernet/CAN, then honestly choose STM32 (or higher-end MCUs).

One final honest truth: There’s no standard answer for selection, only trade-offs. On the premise of meeting functional requirements, choose the lowest cost; when costs are similar, choose the most comfortable for development.

Hope this blog post is helpful to you!

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Related Resources:

• STM32F103 Datasheet

• CH552 Datasheet

• CH559 Datasheet

• WCH Official Examples GitHub

• STM32CubeMX Download

Further Reading:

• CH55x Series MCU Comparison Guide

• USB Device Development Introduction - CH559 HID Device