But I’m really scared about the fact that they only operate at 3.3v. So basically I can’t user any of my 5v modules which would really suck. So what are good ways to go from 5v to 3.3v?
Putting in a logic level converter would kinda destroy the point of going to a smaller controller… Unless of course there are really tiny ones that would basically fit in a pin hole or so…
May I suggest you look at the 32-bit Maple Mini clone,… about $4 from AliExpress;
With the STM32F103 uC, there are a number of input pins that are 5V tolerant… from the documentation:
Part of Maple IDE’s job is to convert normal pin numbers into the corresponding GPIO port and bit when you call functions like pinMode(). It does this using a pin map, which lists the GPIO port and bit for each pin number. The GPIO documentation for your board includes its pin map, which also lists the other peripherals by pin number:
Maple RET6 Edition
Maple Native (Beta)
The current and voltage limitations were determined using the STM32 datasheets. In particular, only some GPIO pins are 5V tolerant, which means that applying 5 volts to a pin and reading it as input or allowing it to drain to ground will not damage that pin. Connecting a voltage higher than 3.3V to a non-5V tolerant pin may damage your board.
The output of a 3.3 Volt logic gate will fall within the range of 5V input signaling, so a voltage converter is not required.
Obviously, not all pins are 5V tolerant on the Maple Mini clone by Baite, but a significant number are which makes experimentation very useful:
Check out the Maple Mini pin map. … go down about 4 paragraphs …
The STM32 Maple Mini is very well supported by this forum… which branched a couple of years back from this forum.