Anyone else mess with the STMicro NUCLEO boards? I picked up one of these to program as a button-activated audio test pattern signal generator (12-bit) pulling lookup tables off a MicroSD card. I paid $11 with a recent Mouser order. Some of these boards are supported on the mbed platform (similar to Arduino, but a much smaller community) and also PlatformIO. This thing is an I/O beast and happens to have Arduino Uno shield compatibility.
https://developer.mbed.org/platforms/ST-Nucleo-F446RE/ (https://developer.mbed.org/platforms/ST-Nucleo-F446RE/)
ARM®32-bit Cortex®-M4 CPU with FPU
Adaptive real-time accelerator (ART Accelerator™) allowing 0-wait state execution from Flash memory
180 MHz max CPU frequency
VDD from 1.7 V to 3.6 V
512 KB Flash
128 KB SRAM System
4 KB SRAM Backup
Timers General Purpose (10)
Timers Advanced-Control (2)
Timers Basic (2)
SPI (4)
I2S (2)
USART (4)
UART (2)
USB OTG Full Speed and High Speed
CAN (2)
SAI (2)
SPDIF-Rx (1)
HDMI-CEC (1)
Quad SPI (1)
Camera Interface
GPIO (50) with external interrupt capability
12-bit ADC (3) with 16 channels
12-bit DAC with 2 channels[/li][/list]
(https://developer.mbed.org/media/cache/platforms/250x250xNucleo64_perf_logo_1024_674FRgg.jpg.250x250_q85.jpg.pagespeed.ic.qcsIMCZ5aG.webp)
Haven't checked that one, but I've been wanting to try this for a while:
http://www.wolinlabs.com/blog/stm32f4.adc.dsp.dac.html
Anyway, I first need to work a little bit more with my Teensy 3.2 and Arduino Due
I bought a few of these STM32 boards plus a Teensy32 and a ESP8266 wifi board in the last month. For $50 I picked up a lot of hardware. I'd been using Uno/Nano and gotten to the point where I wanted more features, more memory, faster processing.
A word to the uninitiated...
The mbed platform is OK but the community, and therefore the # of libraries, is minuscule compared to the Arduino platform. For example the stock mbed i2c library is a skeleton implementation. I had to roll my own to do many things we take for granted on the Arduino i2c and i2cdev libraries. I haven't gotten too far, but porting Arduino libraries for attached devices seems to be the way people are getting mbed to interact with external sensors. Debugging in-code? LOL, no.
So... I tried programming using the STMicro STM32Cube/HAL platform. It took a solid 4 hours of reading and beating my head with a keyboard but I got a program compiling and debugging using GCC/IDLE/OpenOCD. To blink a LED.
To quote a co-worker, "There be dragons."