Arduino Nano ESP32 Experiments

[Chris Savage]

Experiments using the ESP32, based on projects and demos shared by members of Savage///Chats.



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[Jeff_T]

This is not truly specific to the Nano ESP32 so if the topic is moved that's ok but I did do the following test on a Nano ESP32. Also I don't claim the complete code to be mine, I wish I could find the link again, but it showcases two forms of optimization using what are called decorators in micro python. The decorators are called @micropython.native and @micropython.viper , the viper results are phenomenal. The code runs three separate methods on a prime number and prints the timed results at the end.

Code Select Expand

import time
import machine

def test_regular(num):
    if num == 1:
        # 1 is defined as not prime
        return False
       
    elif num > 1:
        # check for factors
        for i in range(2, num):
            if (num % i) == 0:
                # if factor is found, this is not a prime number
                return False
        # No factors found - number is prime
        return True
   
@micropython.native
def test_native(num):
    if num == 1:
        # 1 is defined as not prime
        return False
       
    elif num > 1:
        # check for factors
        for i in range(2, num):
            if (num % i) == 0:
                # if factor is found, this is not a prime number
                return False
        # No factors found - number is prime
        return True
   
@micropython.viper
def test_viper(num:int) -> bool:
    if num == 1:
        # 1 is defined as not prime
        return False
       
    elif num > 1:
        # check for factors
        for i in range(2, num):
            if (num % i) == 0:
                # if factor is found, this is not a prime number
                return False
           

   
def compareRunTime(num):

    start_time = time.ticks_ms()
    output1 = test_regular(num)
    elapsed = time.ticks_ms() - start_time
    print(f"Regular  {elapsed/1000} ms")
   
    regular_time = elapsed
   
    start_time = time.ticks_ms()
    output1 = test_native(num)
    elapsed = time.ticks_ms() - start_time
    native_time = regular_time/elapsed
    print(f"Native  {elapsed/1000} ms ~{round(native_time,1)} times faster")

    start_time = time.ticks_ms()
    output1 = test_viper(num)
    elapsed = time.ticks_ms() - start_time
    viper_time = regular_time/elapsed
    print(f"Viper    {elapsed/1000} ms ~{round(viper_time,1)} times faster")
   
compareRunTime(71569) # This is a prime number
These are the results of the test on my system

>>> %Run -c $EDITOR_CONTENT

MPY: soft reboot
Regular  0.265 ms
Native  0.113 ms ~2.3 times faster
Viper    0.017 ms ~15.6 times faster
>>>

EDIT : here is a link to some useful Viper info https://github.com/micropython/micropython/wiki/Improving-performance-with-Viper-code

[Chris Savage]

Very interesting stuff. More things to try when I get back to this project.