---
title: "STM32 For Beginners [5]: Motors"
date: 2024-10-10T00:36:00+03:00
draft: true
summary: "..."
author: "Rusted Skull"
series: ["STM32 For Beginners"]
tags: ["Embedded", "STM32"]
---

Thus far we've learned very basic ways of making our microcontroller interact with the world: GPIO mostly.
But to build a folkrace robot we need a little bit more. Motors, specifically motors with variable speed would help.
The most simple motor to use in this scenario is a DC motor, like the [Pololu micro metal gearmotors](https://www.pololu.com/category/60/micro-metal-gearmotors).

# Driving DC Motors, Theory

To drive a DC motor, we typically use a H-bridge based motor driver. In the case of the Robotics Club course,
we are given a [Pololu DRV8835 carrier board](https://www.pololu.com/product/2135) which contains the Texas Instruments DRV8835 dual H-bridge
chip. "Dual" in this case means that one board can drive two motors, perfect for a simple differential-drive
folkrace robot.

{{< figure src="https://a.pololu-files.com/picture/0J4056.1200.jpg" caption="Source: https://wwww.pololu.com" >}}

If we look at the "Using the motor driver" section in the "Description" of the carrier board's page,
we notice the following diagram:

{{< figure src="https://a.pololu-files.com/picture/0J4058.600.png" caption="Source: https://www.pololu.com" >}}

The right side is dedicated to the motors, and the left side specifies the input signals expected from the microcontroller.
We immediately notice that for this control scheme, the "phase-enabled mode", we need to generate two PWM
signals, alongside a few GPIO output signals. Let's look a little closer as PWM now, since that's the missing
piece for us.