![]() ![]() In this tutorial, you will learn how servo motors work and how to control them with Arduino. Still need to update the documentation and add examples (here's a start). I should have the new release ready within the next week. Zooming in to max, here we can see perfect synchronization between a signal pair because they use the same timer: Zooming in, the timer to timer synchronization (after phase delay calibration) was only100ns: Here's the logic trace of 8 PWM signals (synchronized) at 25kHz frequency and 10-bit resolution: ![]() The result is the alignment of each signal pair (timer to timer synchronization). This can be essentially calibrated out by using the hpoint (phase) value to delay the PWM signal start. I've found that there's a consistent delay of about 11μs between each signal pair. Each channel pair uses a different timer and/or speed mode.Up to 8 PWM signal pairs are inherently synchronized.New capability to pause/resume the timers to allow PWM startup synchronization.The user will now have the capability of manually attaching (assigning) a pin to any PWM channel. I think this pushes the LEDC capabilities much closer to that of the MCPWM controller and it has the capacity to synchronize more signals than MCPWM. Its not perfect, but multiple PWM signals can be synchronized to within 1μs. The new version will exploit the capabilities of the LEDC controller to add PWM synchronization. For the ESP32, all 16 PWM channels will be available. I've been working on a major update to this library ( version 4.0.0) which will have some significant new capabilities using the LEDC PWM controller of the ESP32/S2/S3/C3. People who can currently use the Arduino core on those devices are likely experienced enough to use the ledc peripheral. My advice would be to focus your library work on the ESP32 and leave the S2 and S3 alone until there is Arduino core support available through the boards manager. ![]() I have never used the Espressif IDF directly, but I guess that is another option. I'm not clear about the long term role that the S2 has in the product line. I also understand that Espressif has slowed work on the S2 core, and was working on the S3. The Arduino S2 core is not available from the board manager, and the procedure for installing it from the development branch is complicated. Both UM and Adafruit recommend using Circuit Python, and advise that the Arduino core is not fully developed and to not use it. The native USB support makes that possible. I have not gotten very far into using it, and mostly used it as an opportunity to experiment with Circuit Python. I have a Feather S2 from Unexpected Maker took forever to work out something to control this, but ended up being quite simple.Ĭurrently awaiting delivery of an ESP32-S2 Saola-1M for testing. I couldn't find any code that puts this multiplexor back to startup status. With LEDc, I don't think there's any purpose (or if it's even possible) to use a timer/channel without dedicating it to a pin. So now I can monitor if a pin is available for use and avoid taking over pins used by other code. even just setting it to input, this mux register switches to function 3 (GPIO). Apparently, after power-up, the GPIO pins are assigned to function 1 (0), but after any code works with a pin. I'm using the LEDc peripheral and have discovered something that's quite simple to check and see if any pin has been assigned to GPIO. I think the reason for not yet offering analogWrite functions with the core is the complexities of utilizing the best resource management strategy to avoid conflicts with other code. the Arduino core provides functions that give analog write / PWM capabilities for these. There's also the Delta Sigma and LEDc peripherals. I think he's using the MPWM peripheral, but didn't look too closely. Thanks Yes, I saw that link about the PWM problem with the servo. ![]()
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