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espressif / arduino-esp32

Arduino core for the ESP32
GNU Lesser General Public License v2.1
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Multithreading timing issue #2001

Closed josefinHeilig closed 5 years ago

josefinHeilig commented 5 years ago

Hi everyone,

I want to use Multi threading on both cores of the ESP32 and 2 examples I found work fine for me: 1: https://www.hackster.io/rayburne/esp32-in-love-with-both-cores-8dd948 2: https://github.com/copercini/esp32-iot-examples/blob/master/multiloop/multiloop.ino

But none of them gives a hint of how to execute the threads at a specific frequency.

I want to use one thread for the updating of 3 synchronized bldc motors. I drive the motors by changing the increment size of each motor to go through a PWM array, while the frequency is (should be) constant. Like in this example: http://www.berryjam.eu/2015/04/driving-bldc-gimbals-at-super-slow-speeds-with-arduino/ This means that I have 9 channels running 3 motors.

I am not sure if it makes sense to have one thread per motor or one thread for all of them. The other threads I want to use for sensor updates, battery check, etc. For Wifi I am using AsyncUDP.

In the second example for Multi threading a delay is used inside of the tasks, but in my understanding that is not making sure that the task is executed again after exact that time?

How can I time my Threads?

I hope my problem becomes clear.

Cheers jh

josefinHeilig commented 5 years ago

I just found vTaskDelayUntil() as opposed to vTaskDelay() and delay() at https://www.freertos.org/vtaskdelayuntil.html

It might solve my issue, but other ideas are welcome.

atanisoft commented 5 years ago

you may benefit from the Ticker library: https://github.com/espressif/arduino-esp32/tree/master/libraries/Ticker

lbernstone commented 5 years ago

I don't understand your exact output requirements, but the RMT peripheral may be easier to use if you are trying to send a particular binary (pseudo-pwm) pattern at a cyclical frequency. There is an arduino class in development, but the IDF code is not too difficult to work with.

stale[bot] commented 5 years ago

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

stale[bot] commented 5 years ago

This stale issue has been automatically closed. Thank you for your contributions.