Search found 353 matches

by shaoziyang
Wed Mar 03, 2021 2:16 am
Forum: General Discussion and Questions
Topic: ESP32 urandom.getrandbits(64) value error
Replies: 2
Views: 59

Re: ESP32 urandom.getrandbits(64) value error

Yes, max value for getrandbits() is 32.
by shaoziyang
Sat Feb 20, 2021 1:08 am
Forum: Raspberry Pi microcontroller boards
Topic: mandelbrot calculation and strange behavior in PICO
Replies: 6
Views: 356

Re: mandelbrot calculation and strange behavior in PICO

I have try to add gc.collect() before calculation, it will decrease the increase time slightly.

It appears to be caused by the print function, this problem only appear on PICO.
by shaoziyang
Fri Feb 19, 2021 2:23 pm
Forum: Raspberry Pi microcontroller boards
Topic: Pico Micropython overclocked twice (250MHz) works fine
Replies: 9
Views: 512

Re: Pico Micropython overclocked twice (250MHz) works fine

Yes, it really works, the calculation time of PI is reduced by almost half. import gc from utime import ticks_ms, ticks_diff def pi(places=100): # 3 + 3*(1/24) + 3*(1/24)*(9/80) + 3*(1/24)*(9/80)*(25/168) # The numerators 1, 9, 25, ... are given by (2x + 1) ^ 2 # The denominators 24, 80, 168 are giv...
by shaoziyang
Fri Feb 19, 2021 12:57 pm
Forum: Raspberry Pi microcontroller boards
Topic: mandelbrot calculation and strange behavior in PICO
Replies: 6
Views: 356

Re: mandelbrot calculation and strange behavior in PICO

calc time: 3526 ms
calc time: 3573 ms
calc time: 3627 ms
calc time: 3666 ms
calc time: 3719 ms
calc time: 3758 ms
calc time: 3812 ms
calc time: 3852 ms
by shaoziyang
Wed Feb 17, 2021 7:53 am
Forum: Raspberry Pi microcontroller boards
Topic: mandelbrot calculation and strange behavior in PICO
Replies: 6
Views: 356

Re: mandelbrot calculation and strange behavior in PICO

It works in PICO, but I have found a strange behavior in PICO, the calculation time increases each time, tens to hundreds of milliseconds each time. There is no such phenomenon on other hardware (such as pyboard, esp32, microbit).

Is this a bug in PICO firmware?
by shaoziyang
Wed Feb 17, 2021 7:49 am
Forum: Raspberry Pi microcontroller boards
Topic: mandelbrot calculation and strange behavior in PICO
Replies: 6
Views: 356

mandelbrot calculation and strange behavior in PICO

I have modify [*]examples/mandel.py[*] for performance testing. from time import ticks_ms, ticks_diff MAX_ITER = 60 MANDEL_CHAR = ( ' ', '.', '`', ',', ':', ';', '|', 'o', '<', '>', '(', ')', '{', '}', '+', '~', '=', '-', '#', '@' ) def run(func, param = None): t1 = ticks_ms() if param == None: func...
by shaoziyang
Wed Dec 23, 2020 9:11 am
Forum: Programs, Libraries and Tools
Topic: Writing A Sensor Library/Driver
Replies: 7
Views: 678

Re: Writing A Sensor Library/Driver

It's not difficult, just try more, and more discussion.
by shaoziyang
Tue Dec 08, 2020 1:43 pm
Forum: Other Boards
Topic: [STM32F469 DISCO] - How to enter DFU mode
Replies: 3
Views: 288

Re: [STM32F469 DISCO] - How to enter DFU mode

You may use onboard stlink to flash hex/bin format firmware.