STM32 platform notes. Most of this information comes from ST AN3427 (Migrating a microcontroller application from STM32F1 to STM32F2 series) and ST AN3364 (How to migrate across STM32 series). The STM32 series of MCUs is divided into series. At time of writing, the available series are: - F1 series (STM32F1) - L1 series (STM32L1) - F2 series (STM32F2) - F4 series (STM32F4) Some notes on the characteristics of, and differences between, the series follow. F1 Series --------- The STM32F1 series is further subdivided into a variety of somewhat compatible "lines". Performance, value, and connectivity line MCUs are available. (There's also an access line, which is ignored in these notes). At time of writing, libmaple supports medium- and high-density performance line MCUs. work to port it to other series is ongoing. Performance line MCU part numbers begin with STM32F101 or STM32F103. The performance line is further subdivided into "densities": low, medium, high, and XL. Value line MCU part numbers begin with STM32F100. Similarly to the performance line, the value line is subdivided into medium and high densities. Connectivity line MCU part numbers begin with STM32F105 or STM32F107. Mercifully, these are not further subdivided by density. F2 Series --------- A revamp of the F1 series, The F2 series address a number of the STM32F1's deficiencies (both silicon bugs and unfortunate design decisions), while maintaining a fair amount of software and pin compatibility. The F2 series is most similar to the F1 connectivity line. Like the connectivity line, STM32F2s come with a USB on-the-go full speed peripheral (like the connectivity line), instead of USB full speed device (like the performance line). F4 Series --------- The F4 series MCUs are essentially equivalent to those in the F2 series, except they have an ARM Cortex M4 core, an FPU, and support a higher clock frequencies (168 MHz instead of 120 MHz). L1 Series --------- This series is intended for low-power applications.