How to power peripherals for arduino?

Question

Arduino

Hey!

iskra js mini (just arduino mini on stm32 with js interpreter inside) runs on 3.3 volts.
There is this display , it works at 5 volts via UART. Do I need a boost converter like this?
Why is there such a 5V-3.3V UART level converter ?
ground and power obviously need to be converted, but is it RX TX too?
On the spark, all pins except just the power supply are tolerant to 5V based on the description.
Ie you need to convert only food? I'm right?

Answer 1

Do I need a boost converter like this?

If the Iskra power input is already 5 V, then this converter is redundant.
And its description (range of input voltages and load currents) - does not shine with completeness.

Why is there such a 5V-3.3V UART level converter? ..... On the spark, all pins except just the power supply are tolerant to 5V based on the description.

In this case, the possible problem is elsewhere. The "5V tolerant" Rx Iskra input will work fine with the 5V Tx Nextion output. But the operation of the Rx Nextion input from the 3 V Tx Iskra output needs to be checked. It is desirable - formally, by fulfilling the condition Voh Iskra ( output one high level voltage) > Vih Nextion ( input one high level voltage). If the condition is not met (or in practice there are failures in data exchange), install a level converter.

Answer 2

The easiest way is to use a display with a voltage of 3.3 Volts. Or 5 Volt Arduino. For example Arduino Mega.
The fact is that the STM32F411 has only 128 KB of RAM, and for applications such as a graphical interface, this is very small. Because the microcontroller is 32-bit and applications consume about 3 times more RAM than the same application for an 8-bit microcontroller.
That is, the same Arduino Mega will work a little slower, but the application will have more functions.