Help me choose MCU

[ElectroCruise]

Hello guys, 

I am building a product, actually am migrating my product from ATmega to STM MCUs, my requirements exactly are as follows,

1. Cortex M0 or better core, >48 MHz
2. 2 Channel 5V DACs
3. 1 Channel CAN for OBD2 Interface
4. 2 Channel ADCs, at least 10 bit resolution
5. 8 GPIOs at least
6. Native USB to UART- Should be able to connect to serial terminal without external debugger.
7. 105/ 125 degrees Celsius Temperature tolerance, AEC qualification is better.

I had a look into STM32G0x1 and the STM32F0 series MCUs, but am still not very sure if this is the right one. Am looking for suggestions and recommendations from the community or any employees.

  

[Andrew Neil]

https://www.st.com/en/development-tools/st-mcu-finder-pc.html

https://www.st.com/en/development-tools/stm32-finder.html

https://www.st.com/content/st_com/en/stm32-mcu-developer-zone.html

 

 

[ElectroCruise]

Hello @Andrew Neil ,

Thanks for the quick reply, I will definitely check out the MCU finder software. 

Now my question is about the crystal less USB feature on the STM32F0x2 MCUs, so can these MCUs be used without external USB to UART converters like FTDI or CH340 to connect MCU to the serial terminal to view data (ex. Tera term)?

Also, can I flash program with USB to UART converters or external debugger, directly to MCU via USB cable?

Thanks!

[EThom.3]

I would probably select one of the STM32L433 versions. I have good experience with that.

For about 15 years or more, I used Atmel AVRs, before switching to STM32. Despite the rather steep learning curve in the beginning, I have not regretted it.

 

Edit: You will need amplifiers for the DACs, if you want 5 V out. But you are probably aware of that.

[LCE]

I'm using both ATmega and STM32, so here are a few comments:

• 2 Channel 5V DACs

-> never seen a 5V capable DAC from a 3.3V MCU, which applies to all STM32, but I'm not sure.

• 2 Channel ADCs, at least 10 bit resolution

-> almost all STM32 have at least a 12-bit ADC with several multiplexed channels.
But compared to the "typical" ATmega ADC, the STM32 ADC is rather low impedance and requires a good driver and / or at least some "big" caps (nF range).

 

In general: 

• Beware the small flash sizes of some STM32 types. 32kB is nothing for a 32bit MCU, even more when working with lots of printf debug output.
• Don't expect too much from the tools such as CubeMX (good enough for basic setup) or the HAL / LL libraries (too much unnecessary stuff in there (flash size...), but good as examples)