PY32F003 Device Guide

The PY32F003 is a low-cost ARM Cortex-M0+ microcontroller particularly well-suited for cost-sensitive applications. This guide covers device-specific features and configurations.

Device Overview

PY32F003 Family Variants

Key Specifications

• Core: ARM Cortex-M0+ @ up to 24MHz
• Voltage: 1.7V to 5.5V operation
• Temperature: -40°C to +85°C (industrial)
• Power: Very low power consumption
• Packages: DFN8, TSSOP20, QFN32

Peripheral Availability

PY32F003 Peripheral Map

Package-Specific Information

DFN8 Package (PY32F003I)

Ultra-compact 2x3mm package - ideal for space-constrained designs.

            DFN8 Pinout (Top View):
               VCC  1 ┌─────┐ 8  PB5/LED
               PA0  2 │     │ 7  PA14-SWDCK/PB6
               PA1  3 │     │ 6  PA13-SWDIO/PA10
               PA2  4 └─────┘ 5  PB0/PF2-NRST

Available Pins:

• Power: VCC, VSS
• Programming: PA13 (SWDIO), PA14 (SWDCK), NRST
• GPIO: PA0, PA1, PA2, PB5
• USART2: PA0 (TX), PA1 (RX)
• ADC: PA2 (Channel 2)

Recommended Usage:

#![allow(unused)]
fn main() {
// Verified working configuration
let tx = gpioa.pa0.into_alternate_af9();  // USART2_TX
let rx = gpioa.pa1.into_alternate_af9();  // USART2_RX
let adc_pin = gpioa.pa2.into_analog();    // ADC input
let led = gpiob.pb5.into_push_pull_output(); // Debug LED
}

Additional Features:

• More GPIO pins available
• Separate analog power (VDDA/VSSA)
• More peripheral pin options
• Better power supply decoupling

Memory Layout

Flash Memory Organization

PY32F003 Flash Layout:
┌─────────────────┐ 0x0800FFFF (64KB variant)
│   User Flash    │ 
│   (Application) │
├─────────────────┤ 0x08007FFF (32KB variant)  
│                 │
├─────────────────┤ 0x08003FFF (16KB variant)
│   System Flash  │ 0x08003000
│   (Bootloader)  │
└─────────────────┘ 0x08000000

RAM Memory Map

PY32F003 RAM Layout:
┌─────────────────┐ 0x20001FFF (8KB variant)
│      SRAM       │
│   (User Data)   │ 
├─────────────────┤ 0x20000FFF (4KB variant)
│                 │
├─────────────────┤ 0x200007FF (2KB variant)
│                 │
└─────────────────┘ 0x20000000

Clock Configuration

Clock Sources

Internal Clocks:

• HSI: 8MHz internal RC oscillator (can be scaled to 24MHz)
• LSI: ~40kHz low-speed internal oscillator

External Clocks (optional):

• HSE: 4-32MHz external crystal/oscillator
• LSE: 32.768kHz external crystal (for RTC)

Recommended Clock Setup

#![allow(unused)]
fn main() {
// Standard 24MHz configuration (proven stable)
let rcc = p.RCC
    .configure()
    .hsi(HSIFreq::Freq24mhz)  // Use internal 24MHz
    .sysclk(24.MHz())         // System clock = 24MHz
    .freeze(&mut p.FLASH);

// Alternative: Use external crystal
let rcc = p.RCC
    .configure()
    .hse(8.MHz())            // 8MHz external crystal
    .sysclk(24.MHz())        // PLL to 24MHz
    .freeze(&mut p.FLASH);
}

Power Management

Supply Requirements

• VDD/VCC: 1.7V to 5.5V (main supply)
• VDDA: Analog supply (same as VDD in most cases)
• VSS/VSSA: Ground (0V)

Power Consumption (Typical @ 3.3V)

Low Power Programming

#![allow(unused)]
fn main() {
use py32f0xx_hal::pwr::{PowerMode, Pwr};

// Enter sleep mode
cortex_m::asm::wfi(); // Wait for interrupt

// Enter stop mode
let pwr = Pwr::new(p.PWR);
pwr.stop_mode();

// Configure wake-up sources
pwr.enable_wakeup_pin(WakeupPin::PA0);
}

Development Tips

DFN8-Specific Considerations

1. Limited pins - Plan pin usage carefully
2. Single-layer PCB friendly - Bottom pad can be difficult
3. Hand soldering - Requires fine-pitch soldering skills
4. Debug access - PA13 on bottom pad may need special connector

Pin Multiplexing Strategy

#![allow(unused)]
fn main() {
// Example: Maximize utility of limited DFN8 pins
// PA0: USART2_TX (communication)
// PA1: USART2_RX (communication) 
// PA2: ADC input (sensing)
// PB5: GPIO output (LED/control)
// PA13: SWDIO (programming - bottom pad)
// PA14: SWDCK (programming)
}

PCB Design Recommendations

DFN8 Package:

• Thermal pad connection to ground plane recommended
• Decoupling: 100nF close to VCC pin
• Crystal placement: Keep HSE crystal close if used
• Debug connector: Consider test points for PA13/PA14

Power Supply:

• Linear regulator for 3.3V from 5V if needed
• Battery operation possible with low-power modes
• Brown-out detection available in software

Common Applications

Sensor Nodes

#![allow(unused)]
fn main() {
// Temperature sensor with serial output
let temp_sensor = adc.convert(&adc_pin);
serial.write_str(&format!("Temp: {}°C\r\n", temp_to_celsius(temp_sensor)));
}

Simple Controllers

#![allow(unused)]
fn main() {
// Button-controlled LED
if button.is_high() {
    led.set_high();
} else {
    led.set_low();  
}
}

Data Loggers

#![allow(unused)]
fn main() {
// Log sensor data periodically
rtc.set_alarm(60); // Every minute
loop {
    cortex_m::asm::wfi(); // Sleep until alarm
    let data = read_sensors();
    log_data(data);
}
}

Debugging and Development

SWD Programming

• SWDIO: PA13 (bottom pad on DFN8)
• SWDCK: PA14
• NRST: Hardware reset (optional)
• VCC/GND: Power for programmer

Serial Debugging

#![allow(unused)]
fn main() {
// Use USART2 for debug output
let mut debug_serial = Serial::usart2(
    p.USART2, 
    (tx, rx), 
    115200.bps(), 
    rcc.clocks
);

// Debug output
writeln!(debug_serial, "Debug: value = {}", value).ok();
}

Migration Notes

From Other STM32F0xx

• Pin compatibility: Check alternate functions
• Clock setup: May need adjustment
• Peripheral differences: Some features may be missing

Between PY32F003 Variants

• Pin count differences: DFN8 vs TSSOP20 vs QFN32
• Memory sizes: Check flash/RAM requirements
• Package-specific features: Some pins only on larger packages

Next Steps

• Try Quick Start Guide with PY32F003
• Explore Serial Examples for communication
• Learn GPIO Control for I/O operations
• Check Hardware Setup for wiring