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/proc/timer_list

1. Kernel Config:
set CONFIG_TIMER_STATS=y Collect kernel timers statistics. can use /proc/timer_stats

2. Using Linux interval timer

3. Accessing SPI

4. Accessing I2C

reference:
[1]. https://elinux.org/Kernel_Timer_Systems
[2]. https://forum.armbian.com/topic/1901-patch-for-quick-interrupt-handling-on-the-h3-fast-gpio/
[3]. https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18842191/Linux+GIC+Driver, the documentation of linux interrupt controller
[4]. http://cs.brown.edu/courses/csci1680/s22/content/threads2.pdf

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TODO:
# Isolating CPUs Using tuned's isolated_cores Option

The initial mechanism for isolating CPUs is specifying the boot parameter isolcpus=cpulist
use [cat /proc/cmdline] to see the boot argument

https://forum.armbian.com/topic/12922-how-can-i-set-isolated-cpu-on-orange-pi-zero/

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux_for_real_time/7/html/tuning_guide/isolating_cpus_using_tuned-profiles-realtime

https://forum.armbian.com/topic/1901-patch-for-quick-interrupt-handling-on-the-h3-fast-gpio/

https://forum.armbian.com/topic/1885-rt-patches-for-sun8i-kernel/

# https://0xax.gitbooks.io/linux-insides/content/Timers/linux-timers-4.html
# https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18842191/Linux+GIC+Driver, the documentation of linux interrupt controller
# https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux_for_real_time/7/html/reference_guide/chap-hardware_interrupts

# https://www.kernel.org/doc/html/v4.14/driver-api/spi.html, SPI programming

# setitimer

# SPI

https://github.com/azorg/spi/blob/master/spi.c

# I2C

https://elinux.org/Interfacing_with_I2C_Devices

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话说2018年春节的时候,3d打印了一个机械臂。

还是老样子,在纸上先画一个机械臂大概的形状

01. 微信图片_20200129003823 

在CAD中画出具体参数,看看用什么养的配置比较合适,作业半径会是多少。02. IMG_20180217_171804 

确定参数就可以开始做三维建模。

03. IMG_20181231_150924

一步一步开始搭建机械臂的每个部分。
...continue reading

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最近想玩玩eagle。但是运行eagle却发现了这个错误

./eagle: error while loading shared libraries: libjpeg.so.62: cannot open shared object file: No such file or directory

显然,第一步想到的就是安装lib

$ sudo apt-get install libjpeg62

但是,看到libjpeg已经安装过了,而且问题依旧。google之,发现可能由于eagle用到的是32位的库。那么就需要加上32位的限定了

$ sudo apt-get install libjpeg62:i386

安装后,eagle成功运行,问题解决

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Food is the most important element in Chinese culture. Shanghai being one of the biggest city in China has its long traditional and broad selection of foods. We mixed Shanghai Sandwich and Littlebits to bring one of the most famous breakfast of Shanghai to life.

Shanghai Sandwich is the perfect breakfast in Shanghai! It is one of the most famous local dishes with long tradition and full of flavors. Our project uses littleBits to help to make a perfect Shanghai Sandwich.

Instructions

sketch01

sketch02

sketch03

sketch04

sketch05

sketch06

sketch07

  1. Step 1. Get all the ingredients and materials ready. See the illustration we had as the recipe for the Shanghai Sandwich.

...continue reading

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