Up to now, there are a lot of ARDUINO board based on Cortex Mx, see here and below.
Arduino STAR – OTTO is based on the powerful STM32F469BI
- Key Features
- High-performance STM32F469BIT6 MCU with 2-Mbyte Flash memory, 384-Kbyte SRAM
- Memory: 16-Mbyte SDRAM, 128-Kbyte EEPROM, microSD slot
- Wi-Fi 802.11b/g/n 2.4 GHz link (Espressif ESP8266)
- MIPI® DSI display interface
- 2x MEMS digital microphones
- Headphone and speaker output
- USB host interface
- Camera connector
- Arduino™ Uno, Due, Mega connectors
- Supported by Arduino™ IDE and Arduino™ Studio online IDE
All the STM X-NUCLEO are compatible to Arduino shield.