2
\$\begingroup\$

The ESP32 data sheet talks about "Motor PWM" vs "LED PWM". The "LED PWM" seems to be a quite straightforward feed-forward circuit, while the "Motor PWM" also has "three fault detection signals, three event-capture signals, and three sync signals".

I'm looking for some explanation what all those extra inputs for "Motor PWM" are for -- which problems do they solve? And then also some example circuitry for how to use them.

It appears to me that I can use the "LED PWM" just find to drive a DC motor via an amplifier suitable for switching inductive loads?

\$\endgroup\$
3
  • \$\begingroup\$ Explanations of the capabilities and applications of products should be obtained from the product manufacturer. This site is not a substitute for product support. Controlling motors is more complex than controlling LEDs. You need to understand motors. To a great extent controlling a motor is controlling the driven load. \$\endgroup\$
    – user80875
    Commented Aug 25, 2019 at 19:03
  • \$\begingroup\$ Have you looked at the User Manual? It has more details. \$\endgroup\$
    – Tyler
    Commented Aug 25, 2019 at 20:08
  • \$\begingroup\$ @Tyler: link to the document you have in mind? fccid.io/2AC7Z-ESPWROOM32D/User-Manual/User-Guide-3688269.pdf does not mention PWM. \$\endgroup\$ Commented Aug 25, 2019 at 23:31

1 Answer 1

3
\$\begingroup\$

What you wish to know is covered in reasonable detail here in Espressif's ~= 1500 page "Programming guide".
See below for section covering the - MCWPCM = Motor PWM Control unit.

The overall 'Programming Guide' is a must see for any ESP32 users.

Guide Downloads

Latest stable version PDF - 1497 pages !!! :-). June 26 2019

___________________________________

MCPWM - Motor PWM:

Espressif's Programming guide - MCWPCM unit - 20+ pages (depending on your screen size :-) ).

They say:

MCPWM Overview

"ESP32 has two MCPWM units which can be used to control different types of motors. Each unit has three pairs of PWM outputs.

A detailed block diagram of the MCPWM unit is shown below. Each A/B pair may be clocked by any one of the three timers Timer 0, 1 and 2. The same timer may be used to clock more than one pair of PWM outputs. Each unit is also able to collect inputs such as SYNC SIGNALS, detect FAULT SIGNALS like motor overcurrent or overvoltage, as well as obtain feedback with CAPTURE SIGNALS on e.g. a rotor position.

Contents

  • Configure a basic functionality of the outputs
  • Operate the outputs to drive a motor
  • Adjust how the motor is driven
  • Capture external signals to provide additional control over the outputs
  • Use Fault Handler to detect and manage faults
  • Add a higher frequency Carrier, if output signals are passed through an isolation
    transformer
  • Configuration and handling of Interrupts.

enter image description here

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.