What to know before you start an STM32 project
- STM32 is a family, not a chip. Parts range from ultra-low-power Cortex-M0+ (STM32L0, G0) to Cortex-M7 (STM32H7). Picking the family is the first and most expensive decision.
- Hexcode Plus delivers STM32 work end to end: schematic and PCB, drivers, RTOS application, bootloader, OTA and production test, under one roof in Thiruvananthapuram.
- Low-power and real-time are where STM32 earns its place. Deterministic interrupts, mature low-power modes and long product lifecycles suit industrial, medical and battery-powered devices.
- You receive the source. Projects are delivered with full firmware source, build instructions and hardware design files so you are not locked to us.
Choosing the right STM32 family
The STM32 portfolio is large, and most over-spending on STM32 projects traces back to choosing a family by habit rather than by requirement. A short comparison of the families we use most:
| Family | Core | Typical use |
|---|---|---|
| STM32L0 / L4 | Cortex-M0+ / M4 | Battery-powered sensors, metering, LoRaWAN nodes where sleep current dominates |
| STM32G0 / G4 | Cortex-M0+ / M4 | Cost-sensitive control, motor drives, general-purpose products |
| STM32F4 | Cortex-M4F | Mature mid-range designs: DSP-light signal processing, USB, Ethernet, medical devices |
| STM32H7 | Cortex-M7 | High-performance control, graphics, audio and fast data acquisition |
| STM32WL / WB | M4 + radio | Integrated sub-GHz LoRa or Bluetooth LE radio on a single chip |
We pick on three questions: how long must the battery last, how fast must the control loop run, and which peripherals can you not do without. The datasheet answers the rest.
What we build on STM32
- Peripheral drivers using HAL where speed of development matters and LL or register-level code where timing or code size matters.
- RTOS-based applications on FreeRTOS, with task design, priorities and inter-task communication documented.
- Low-power firmware using Stop and Standby modes, peripheral gating, DMA and wake-on-interrupt, verified with a current profiler rather than estimated.
- Bootloaders and OTA with dual-bank or swap-based update, image signing and rollback.
- Connectivity over UART, SPI, I2C, CAN, USB, Ethernet, LoRaWAN, Bluetooth LE and cellular modules.
- Board bring-up and production test fixtures so the first units out of the factory are checked automatically.
These capabilities link directly to our firmware development and PCB design services.
Tooling and delivery
Firmware is built with the GNU Arm toolchain and CMake or STM32CubeIDE, debugged over SWD with ST-LINK or J-Link, and kept in Git. We use STM32CubeMX only to generate peripheral initialisation, then own the code from there, because generated code you cannot read is a liability at year three of a product.
Every delivery includes source, a reproducible build, a hardware test checklist and a short design note that records why key decisions were made. That note is usually what a successor team thanks you for.
Common STM32 pitfalls we design around
- Leaving unused GPIO floating, which can add tens of microamps of leakage and ruin a coin-cell power budget.
- Clock configuration copied from an example and left running at full speed when the application could run slower and sleep more.
- No watchdog strategy, so a rare lock-up becomes a field return.
- Flash layout decided late, leaving no room for a bootloader or a second image.
- Skipping option bytes and read-out protection, which leaves production firmware readable.
Sources and further reading
- STMicroelectronics — STM32 32-bit Arm Cortex-M microcontrollers — Manufacturer overview of the STM32 families, datasheets and reference manuals.
- STMicroelectronics — STM32Cube ecosystem — Official HAL, LL, CubeMX and CubeIDE tooling referenced above.
- FreeRTOS — Documentation for the RTOS most commonly used on STM32 projects.
Last reviewed: October 2026. Regulations and product availability change; confirm current rules with the issuing authority before you commit to a design.