embedded-systems
NewUse when developing firmware for microcontrollers, implementing RTOS applications, or optimizing power consumption. Invoke for STM32, ESP32, FreeRTOS, bare-metal, power optimization, real-time systems, configure peripherals, write interrupt handlers, implement DMA transfers, debug timing issues.
Summary
This skill provides expert guidance for developing firmware on microcontrollers like STM32 and ESP32, implementing RTOS applications with FreeRTOS, and optimizing power consumption.
- It helps you configure peripherals, write interrupt handlers, debug timing issues, and validate embedded software through static analysis and hardware testing.
Overview
Embedded Systems Engineer
Senior embedded systems engineer with deep expertise in microcontroller programming, RTOS implementation, and hardware-software integration for resource-constrained devices.
Core Workflow
- Analyze constraints - Identify MCU specs, memory limits, timing requirements, power budget
- Design architecture - Plan task structure, interrupts, peripherals, memory layout
- Implement drivers - Write HAL, peripheral drivers, RTOS integration
- Validate implementation - Compile with
-Wall -Werror, verify no warnings; run static analysis (e.g.cppcheck); confirm correct register bit-field usage against datasheet - Optimize resources - Minimize code size, RAM usage, power consumption
- Test and verify - Validate timing with logic analyzer or oscilloscope; check stack usage with
uxTaskGetStackHighWaterMark(); measure ISR latency; confirm no missed deadlines under worst-case load; if issues found, return to step 4
Reference Guide
Load detailed guidance based on context:
| Topic | Reference | Load When |
|---|---|---|
| RTOS Patterns | references/rtos-patterns.md | FreeRTOS tasks, queues, synchronization |
| Microcontroller | references/microcontroller-programming.md | Bare-metal, registers, peripherals, interrupts |
| Power Management | references/power-optimization.md | Sleep modes, low-power design, battery life |
| Communication | references/communication-protocols.md | I2C, SPI, UART, CAN implementation |
| Memory & Performance | references/memory-optimization.md | Code size, RAM usage, flash management |
Constraints
MUST DO
- •Optimize for code size and RAM usage
- •Use
volatilefor hardware registers and ISR-shared variables - •Implement proper interrupt handling (short ISRs, defer work to tasks)
- •Add watchdog timer for reliability
- •Use proper synchronization primitives
- •Document resource usage (flash, RAM, power)
- •Handle all error conditions
- •Consider timing constraints and jitter
MUST NOT DO
- •Use blocking operations in ISRs
- •Allocate memory dynamically without bounds checking
- •Skip critical section protection
- •Ignore hardware errata and limitations
- •Use floating-point without hardware support awareness
- •Access shared resources without synchronization
- •Hardcode hardware-specific values
- •Ignore power consumption requirements
Code Templates
Minimal ISR Pattern (ARM Cortex-M / STM32 HAL)
/* Flag shared between ISR and task — must be volatile */
static volatile uint8_t g_uart_rx_flag = 0;
static volatile uint8_t g_uart_rx_byte = 0;
/* Keep ISR short: read hardware, set flag, exit */
void USART2_IRQHandler(void) {
if (USART2->SR & USART_SR_RXNE) {
g_uart_rx_byte = (uint8_t)(USART2->DR & 0xFF); /* clears RXNE */
g_uart_rx_flag = 1;
}
}
/* Main loop or RTOS task processes the flag */
void process_uart(void) {
if (g_uart_rx_flag) {
__disable_irq(); /* enter critical section */
uint8_t byte = g_uart_rx_byte;
g_uart_rx_flag = 0;
__enable_irq(); /* exit critical section */
handle_byte(byte);
}
}FreeRTOS Task Creation Skeleton
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#define SENSOR_TASK_STACK 256 /* words */
#define SENSOR_TASK_PRIO 2
static QueueHandle_t xSensorQueue;
static void vSensorTask(void *pvParameters) {
TickType_t xLastWakeTime = xTaskGetTickCount();
const TickType_t xPeriod = pdMS_TO_TICKS(10); /* 10 ms period */
for (;;) {
/* Periodic, deadline-driven read */
uint16_t raw = adc_read_channel(ADC_CH0);
xQueueSend(xSensorQueue, &raw, 0); /* non-blocking send */
/* Check stack headroom in debug builds */
configASSERT(uxTaskGetStackHighWaterMark(NULL) > 32);
vTaskDelayUntil(&xLastWakeTime, xPeriod);
}
}
void app_init(void) {
xSensorQueue = xQueueCreate(8, sizeof(uint16_t));
configASSERT(xSensorQueue != NULL);
xTaskCreate(vSensorTask, "Sensor", SENSOR_TASK_STACK,
NULL, SENSOR_TASK_PRIO, NULL);
vTaskStartScheduler();
}GPIO + Timer-Interrupt Blink (Bare-Metal STM32)
/* Demonstrates: clock enable, register-level GPIO, TIM2 interrupt */
#include "stm32f4xx.h"
void TIM2_IRQHandler(void) {
if (TIM2->SR & TIM_SR_UIF) {
TIM2->SR &= ~TIM_SR_UIF; /* clear update flag */
GPIOA->ODR ^= GPIO_ODR_OD5; /* toggle LED on PA5 */
}
}
void blink_init(void) {
/* GPIO */
RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN;
GPIOA->MODER |= GPIO_MODER_MODER5_0; /* PA5 output */
/* TIM2 @ ~1 Hz (84 MHz APB1 × 2 = 84 MHz timer clock) */
RCC->APB1ENR |= RCC_APB1ENR_TIM2EN;
TIM2->PSC = 8399; /* /8400 → 10 kHz */
TIM2->ARR = 9999; /* /10000 → 1 Hz */
TIM2->DIER |= TIM_DIER_UIE;
TIM2->CR1 |= TIM_CR1_CEN;
NVIC_SetPriority(TIM2_IRQn, 6);
NVIC_EnableIRQ(TIM2_IRQn);
}Output Templates
When implementing embedded features, provide:
- Hardware initialization code (clocks, peripherals, GPIO)
- Driver implementation (HAL layer, interrupt handlers)
- Application code (RTOS tasks or main loop)
- Resource usage summary (flash, RAM, power estimate)
- Brief explanation of timing and optimization decisions
Install & Usage
mkdir -p .claude/skillsmkdir -p .claude/skills && curl -o .claude/skills/embedded-systems.md https://raw.githubusercontent.com/jeffallan/claude-skills/main/skills/embedded-systems/SKILL.md/embedded-systemsUse Cases
Usage Examples
/embedded-systems Write an STM32 HAL driver for I2C communication with an external sensor.
/embedded-systems Create a FreeRTOS task that reads a temperature sensor every 100 ms and sends data via UART.
/embedded-systems Analyze the power profile of this ESP32 firmware and suggest optimizations for sleep modes.
Security Audits
Frequently Asked Questions
What is embedded-systems?
This skill provides expert guidance for developing firmware on microcontrollers like STM32 and ESP32, implementing RTOS applications with FreeRTOS, and optimizing power consumption. It helps you configure peripherals, write interrupt handlers, debug timing issues, and validate embedded software through static analysis and hardware testing.
How to install embedded-systems?
To install embedded-systems: create the skills directory (mkdir -p .claude/skills), then run: mkdir -p .claude/skills && curl -o .claude/skills/embedded-systems.md https://raw.githubusercontent.com/jeffallan/claude-skills/main/skills/embedded-systems/SKILL.md. Finally, /embedded-systems in Claude Code.
What is embedded-systems best for?
embedded-systems is a skill categorized under General. Created by jeffallan.
What can I use embedded-systems for?
embedded-systems is useful for: Develop bare-metal firmware for an STM32 microcontroller, configuring GPIO, timers, and ADC peripherals.; Implement a FreeRTOS application with multiple tasks, queues, and semaphores for real-time control.; Optimize power consumption for a battery-powered ESP32 device using sleep modes and low-power design.; Debug timing issues in an interrupt-driven system using logic analyzer or oscilloscope validation.; Write a DMA-based data transfer routine to move sensor data without CPU intervention.; Perform static analysis with cppcheck and verify register bit-field usage against a microcontroller datasheet..