Where to choose microcontrollers and other electronic components?

Question

Electronics

Good afternoon everyone. I'm new to hardware, I've never worked with it before. There was a problem, you need to control 12 servomotors. I'm going to use a raspberry, but I need a generator controlled via I2C pwm (PWM) for 12+ outputs, something like this.
But I want to do it myself, as I understand it, there are special microcontrollers with a large number of PWM outputs and I2C. I dug up some on the Internet, but not enough ... How do you choose microcontrollers? Something like a table, or a list with parameters? What about other electronic components like voltage regulators? For example, I need a constant voltage regulator with a 5v output, I found tLM7805 , but it is 1.5 Amperes, where can I find the same ones for 3 Amperes?
Thanks to all.

Answer 1

We take the manufacturers' brochures, look at the "approximate characteristics", choose what our eye fell on and then smoke the datasheets.
By manufacturers:
NXP - ARM (Xs as their controllers are called, never considered)
Atmel - AVR (Atmega), ARM (All sorts of SAM blah blah blah)
ST - ARM (STM32)
TI - to be honest, I'm not sure that they are controllers they do, but Arm's SOCs are not bad (but expensive)
there are still all sorts of MIPs - but I don't know who produces them and what's inside (I know that they can separately clock the periphery, asynchronously with the core, so to speak - IMHO an overly specific feature).
For your task, in principle, a simple atmega (the cheapest variant of all possible) is suitable.
But in general ... Ada has a seductive piece of iron, I would probably take it, for the sake of interest. And besides, there will be fewer places where you can screw up - relevant for a beginner.

Answer 2

There is a suspicion that the raspberry in this case is from a cannon on sparrows, something simpler is enough.
Regarding PWM: the link says that PCA9685 is used, if you want to do it yourself, you can use it. You can see what Google says about "32 channel pwm driver" for example.

Answer 3

As an option "from what it was", you can use any atmega with the required number of free legs and make them programmatically PWM, given that the PWM frequency is usually not a high usual mark, with the right approach, it can give a PWM for 150-200 outputs without loss of performance.

Answer 4

driver for 18 servos with I2C
control amperka.ru/product/arduino-multiservo-shield

Answer 5

mcu.ru/parametric