技术笔记

修改include/apue.h

在include/apue.h增加

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#include <sys/sysmacros.h>

修改stdio/buf.c

打开apue.3e/stdio/buf.c，搜索_LP64，大致在（文件的89～93行），将其删除

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#ifdef _LP64
#define _flag __pad[4]
#define _ptr __pad[1]
#define _base __pad[2]
#endif

将is_unbuffered, is_linebuffered和buffer_size替换如下

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int
is_unbuffered(FILE *fp)
{
        return(fp->_flags & _IONBF);
}

int
is_linebuffered(FILE *fp)
{
        return(fp->_flags & _IOLBF);
}

int
buffer_size(FILE *fp)
{
#ifdef _LP64
        return(fp->_IO_buf_end - fp->_IO_buf_base);
#else
        return(BUFSIZ); /* just a guess */
#endif
}

#else

#error unknown stdio implementation!

#endif

copy头文件和库

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sudo cp ./include/apue.h /usr/include/
sudo cp ./lib/libapue.a /usr/lib/

oh-my-tmux

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cd
git clone https://github.com/gpakosz/.tmux.git
ln -s -f .tmux/.tmux.conf
cp .tmux/.tmux.conf.local .

add lines at the end of ~/.tmux.conf.local

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	# force Vi mode
#   really you should export VISUAL or EDITOR environment variable, see manual
set -g status-keys vi
set -g mode-keys vi

# replace C-b by C-a instead of using both prefixes
set -gu prefix2
unbind C-a
unbind C-b
bind-key -T copy-mode-vi 'v' send -X begin-selection
bind-key -T copy-mode-vi 'y' send -X copy-selection-and-cancel
set -g prefix M-o
bind M-o send-prefix

install zsh and oh-my-zsh

add 185.199.108.133 raw.githubusercontent.com t o/etc/hosts

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sudo apt install zsh
sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"
chsh -s $(which zsh)

install nodejs

install nvm

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curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.1/install.sh | bash
source ~/.zshrc
nvm list-remote
nvm install v20.8.0
node -v

npm源

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npm config set registry https://registry.npmmirror.com

install hexo and pandoc

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npm install -g hexo-cli
sudo apt install pandoc

install hexo-theme-next

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cd blog
npm install hexo-theme-next

theme-next patch

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diff --git a/_config.yml b/_config.yml
index 5059e2e..e4daac4 100644
--- a/_config.yml
+++ b/_config.yml
@@ -40,8 +40,8 @@ custom_file_path:
 # ---------------------------------------------------------------

 favicon:
-  small: /images/favicon-16x16-next.png
-  medium: /images/favicon-32x32-next.png
+  small: /images/favicon-16x16.png
+  medium: /images/favicon-32x32.png
   apple_touch_icon: /images/apple-touch-icon-next.png
   safari_pinned_tab: /images/logo.svg
   #android_manifest: /images/manifest.json
@@ -164,9 +164,9 @@ sidebar:
 # Sidebar Avatar
 avatar:
   # Replace the default image and set the url here.
-  url: #/images/avatar.gif
+  url: /images/maru.jpeg
   # If true, the avatar will be dispalyed in circle.
-  rounded: false
+  rounded: true
   # If true, the avatar will be rotated with the cursor.
   rotated: false

@@ -501,7 +501,7 @@ math:

   # hexo-renderer-pandoc (or hexo-renderer-kramed) required for full MathJax support.
   mathjax:
-    enable: false
+    enable: true
     # See: https://mhchem.github.io/MathJax-mhchem/
     mhchem: false

@@ -712,7 +712,7 @@ firestore:
 # Show Views / Visitors of the website / page with busuanzi.
 # Get more information on http://ibruce.info/2015/04/04/busuanzi
 busuanzi_count:
-  enable: false
+  enable: true
   total_visitors: true
   total_visitors_icon: user
   total_views: true
@@ -812,9 +812,11 @@ pdf:

# Mermaid tag
 mermaid:
-  enable: false
+  enable: true
   # Available themes: default | dark | forest | neutral
-  theme: forest
+  theme:
+    light: default
+    dark: dark


 # ---------------------------------------------------------------
@@ -894,6 +896,7 @@ vendors:
   # MathJax
   # mathjax: //cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js
   mathjax:
+    enable: true

   # KaTeX
   # katex: //cdn.jsdelivr.net/npm/katex@0/dist/katex.min.css
diff --git a/layout/_partials/footer.swig b/layout/_partials/footer.swig
index f60ea9b..dc5f8e9 100644
--- a/layout/_partials/footer.swig
+++ b/layout/_partials/footer.swig
@@ -42,6 +42,12 @@
   {%- endif %}
 </div>

+<div class=BbeiAn-info">
+  {{ __('<E6><B5><99>ICP<E5><A4><87>') }} -
+  <a href="http://www.miitbeian.gov.cn/">20003462<E5><8F><B7></a>
+  </a>
+</div>
+
 {%- if theme.footer.powered %}
   <div class="powered-by">
     {%- set next_site = 'https://theme-next.org' %}

下载emacs 29.1

• gi t clone的方式，需要autogen一下

install dependencies

树莓派源

cat /etc/apt/sources.list

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deb http://mirrors.aliyun.com/raspbian/raspbian/ bullseye  main non-free contrib rpi
deb-src http://mirrors.aliyun.com/raspbian/raspbian/ bullseye main non-free contrib rpi

安装emacs依赖

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sudo apt install libxpm-dev libgif-dev libgnutls28-dev libgtk-3-dev libjpeg-dev libtiff-dev libncurses-dev libgccjit-10-dev

编译

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./configure --with-native-compilation
make -j
sudo make install

树莓派小电台

参考炬峰的视频，来搞个电台玩玩。

r pi t x

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git clone https://github.com/F5OEO/rpitx
cd rpitx
./install.sh

sudo reboot

cd rpitx
./easytest.sh # FmRds

windows安装SDR软件

• 淘宝买一个软件无线电R820T2+RTL2832U
• 下载地址

树莓派设置

audio输入输出设置

• Audio Inputs - USB Audio Device
• Audio Outputs - Analog

验证输入输出

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arecord -f cd - | aplay -V sterio -

修改testfmrds.sh脚本

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sudo arecord -f cd -D plughw:2,0 -c 2 - | sudo ./pifmrds -freq "$1" -audio -

修改/boot/config.txt

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# Enable audio (loads snd_bcm2835)
dtparam=audio=off

测试

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./testfmrds.sh 434

rplidar

build on the pi and dev machine

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cd ~/code/dep_ws/src
git clone https://github.com/Slamtec/sllidar_ros2.git
cd ..
colcon build --symlink-install
source install/setup.bash
ros2 launch sllidar_ros2 view_sllidar_launch.py

for normal rplidar

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sudo apt install ros-foxy-rplidar-ros

enable image

flowchart
    A[Driver Node] ---> B["/image_raw
    sensor_msgs/Image"] ---> C[Algorithms & Stuff]
    E["/image_raw/compressed
    sensor_msgs/CompressedImage"]
    B <-- image_transport_library/nodes --> E

install dependencies

on the dev machine

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sudo apt-get install ros-foxy-v4l2-camera
sudo apt install ros-foxy-rqt-image-view

on the pi, add start_x=1 to /boot/firmware/config.txt

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sudo apt install libtheora-dev libogg-dev v4l-utils
cd ~/code/dev_dep/src
git clone -b foxy https://gitlab.com/boldhearts/ros2_v4l2_camera.git
git clone https://github.com/ros-perception/image_transport_plugins.git -b foxy-devel
git clone https://github.com/ros-perception/image_common.git -b foxy
git clone https://github.com/ros-perception/vision_opencv.git -b foxy
git clone https://github.com/ros-drivers/usb_cam.git -b ros2
cd ..
colcon build --symlink-install

Launch the camera

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cd ~/code/dev_ws
source install/setup.bash
ros2 launch articubot_one camera.launch.py

on the dev machine

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cd ~/code/dev_ws
source install/setup.bash
rviz2 -d src/articubot_one/config/main.rviz
ros2 run rqt_image_view rqt_image_view

ros2 flow

stateDiagram-v2
    Command_Velocity --> Diff_Dirve_Controller
    state ros2_control {
        Diff_Dirve_Controller --> Hardware_interface: Req. Motor Velocities Velocity Cmd Interfaces
        Controller_Manager
        Hardware_interface --> Joint_State_Broadcaster: Encoder position state
    }
    Hardware_interface --> Car
    Joint_State_Broadcaster --> /joint_states
    /joint_states --> Off_to_robot_state_publisher

install packages

install ros2 controll

要注意的是如果ubuntu20.04都是源码编译ros，需要跳过这一步，因为会失败。总之我是通过源码编译的，因为树莓派在20.04系统64位的暂时没法烧录成功。

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sudo apt install ros-foxy-ros2-control ros-foxy-ros2-controllers ros-foxy-xacro

需要从这里开始源码编译。

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git clone https://github.com/ros/angles.git -b foxy-devel
git clone -b ros2 https://github.com/ros-drivers/ackermann_msgs.git
git clone https://github.com/ros-controls/control_toolbox.git -b foxy
git clone https://github.com/ros-controls/realtime_tools.git -b foxy-devel
git clone https://github.com/ros-controls/control_msgs.git -b foxy-devel
git clone https://github.com/ros-controls/ros2_controllers.git -b foxy
git clone https://github.com/ros-controls/ros2_control.git -b foxy
git clone https://github.com/ros/xacro.git
git checkout 2.0.7

~/.bashrc

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source ~/ros2_foxy/ros2-linux/setup.bash
source /opt/ros/foxy/setup.bash

install joystick test

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sudo apt install ros-foxy-joy joystick jstest-gtk evtest
evtest
jstest-gtk

install libserial

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sudo apt install libserial-dev

joystick flow

stateDiagram-v2
    [*] --> Linux_Joystick_Driver
    Linux_Joystick_Driver --> Joy_Node
    Joy_Node --> /Joy
    /Joy --> /Other_Nodes
    /Other_Nodes --> /whatever
    /Joy --> e.g.teleop_twist_joy
    e.g.teleop_twist_joy --> /cmd_vel

ros2 joy

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ros2 run joy joy_enumerate_devices
ros2 run joy joy_node
ros2 topic echo /joy

dev_ws

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mkdir ~/code/dev_ws
mkdir src && cd src
git clone https://github.com/joshnewans/joy_tester
git clone https://github.com/joshnewans/diffdrive_arduino
git clone https://github.com/joshnewans/articubot_one
git checkout 174b3f31
git clone https://github.com/joshnewans/serial
git clone https://github.com/joshnewans/teleop_twist_joy
colcon build --symlink-install
source install/setup.bash
ros2 run joy_tester test_joy

config/my_controllers.yaml

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wheel_separation: 0.177
    wheel_radius: 0.042

description/ros2_control.xacro

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<param name="enc_counts_per_rev">1321</param>

端午节到了，👨👩带我和妹妹一起去朱家尖。到了以后，我们在楼下的🍴里吃饭。吃完饭我们在酒店里睡觉。睡觉起来以后，我们一起到🏖️堆起了沙堡。第一步我先画好了我们的地盘。第二步，我们挖出了一条护城河。👨拿着大铲子，挖出了很深的一个坑。我想到了一个好主意，我把👨挖出来的土，都放在地盘的边缘上。第三步，我叫妹妹拿着🪣，打好多水倒进护城河里，我叫妈妈把这些泥土弄结实。而我把所有的泥土都弄到边线上。

后来我拿着大耙子，画出了一条护城河的边缘，然后我拿了一个小🔧，帮👨一起挖护城河。挖了一半，我感觉水不太够了。我和妹妹赶紧跑到海边，拿小🪣灌了一大桶水。我们赶紧跑回来，把水洒在护城河里。然后我赶紧拿起小工具继续挖呀挖。我们挖呀挖，挖呀挖，堆呀堆，堆呀堆，堆好了大半个沙堡。水又不够了，我和妹妹赶紧跑到海边，拿起水桶，刚准备灌水，忽然一阵🌊飘来，我和妹妹一起把水都给接了过来。我和妹妹大喊起来：“爸爸妈妈，马上就要涨潮啦！”我和妹妹急忙提起🪣，跑了回去。我们几个赶紧搭呀搭，搭呀搭，快速地搭了起来。只剩最后一点了，我们几个飞快地搭了起来。终于搭完了，只剩最后一个，就是挖护城河。我和妹妹赶紧来到海边，拿起🪣，这是又有一阵🌊飘来了。我和妹妹跑了回来，刚好👨👩挖好了护城河。我和妹妹把水都洒了进去。天色已经差不多了，我们也该吃饭了。我们到了🏨楼下，开始吃饭。吃完饭，我们准备去🚶‍♀️。

🚶‍♀️的时候，我们走到了隔壁一家🏨里，到了那边，我看见了三只🐱。第一只🐱叫做“🍮”，第二只🐱叫做“咪咪”，第三只🐱叫做“小小”。那三只🐱真的好可爱。那三只🐱颜色各不相同。🍮的颜色是黑白相间的，咪咪的颜色是灰白色的，小小的颜色是跟🍮一样，是黑白相间的。🍮它喜欢吃猫粮和鱼条。咪咪喜欢吃狗尾巴草。小小它喜欢吃猫粮。我们跟🐱拜拜了以后就去🏨睡觉了。

第二天，我们先到楼下吃了早饭。早饭非常丰富，有🍜，炒粉，粽子，还有好多好多好吃的。吃完早饭，我们去看了🐱。只看到了咪咪，剩下的🐱全没有看到。我们给咪咪喂了好多好多的草。后来我在那边知道，咪咪抓过很多很多的🐭。因为没有看到其他的🐱，所以👩带我们到海边去挖沙了。👩在旁边的🪨上，抓到了一只小🦀️。我和妹妹把沙子放在磨具里，做出了好多个冰淇凌。我们还在旁边堆了个小山，也就是沙子山。

到了中午，我们一起去吃完了午饭。吃完午饭，我们到🛏️准备睡觉。妹妹在🛏️唱了一首“找朋友”，找呀找呀找画人，找到一个画画人，敬个礼呀握握手，你是我滴画画人。起床了以后，我在楼下写作业，妹妹在旁边吵吵闹闹地玩。写完作业，我们一起玩，然后等雨停了，我们又来到了海边。我跟妹妹在旁边挖了一个大水坑。我和妹妹一起把水给填满，我和妹妹在水坑里蹦来蹦去，跳来跳去。

到了🌃，我们在旁边的店里吃了一顿晚餐。👩点了🦪，🐙，🐚，海瓜子，扇贝。我还喝了北冰洋，可乐。👨喝了🍺，杨梅酒。

我们吃完饭，回到家，躺在🛏️就睡着了。

第三天，我们刚起床，外面就哗哗哗地下了大雨，我发现了一句👩‍🏫叫我们的谚语：“有雨山戴帽，无雨半山腰”。我们准备回家了。我们告别了大海、🏖️，还有小🦀️，🐱。我们来到🚗上，高兴地回到了🏠。

真是一个快乐的端午啊！下一次🤷‍♀️👨👩还会带我们去哪里⛱️。我相信下次还会带我们去更好的地方玩！

Prepare the repo

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cd ~/code
git clone https://github.com/joshnewans/serial_motor_demo.git
cd serial_motor_demo
colcon build --symlink-install

Client gui at the ubuntu22

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source install/setup.bash
ros2 run serial_motor_demo gui

run at the pi

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source install/setup.bash
ros2 run serial_motor_demo driver --ros-args -p serial_port:=/dev/ttyUSB0 -p baud_rate:=57600 -p loop_rate:=30 -p encoder_cpr:=1321

Build the motor

Assemble the car

网络搭建

首先配置raspberry pi和ubuntu 20.04（开发机）到一个网络，建议买一个GL-MT300N-V2，然后把两台ip都配置到192.168.3.*

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192.168.3.119 pi
192.168.3.120 robot

robot is the dev machine, and pi is my raspberry pi.

config /etc/netplan/50-cloud-init.yaml on dev machine.

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network:
    version: 2
    ethernets:
        renderer: networkd
        enp0s5:
            dhcp4: no
            addresses:
                - 192.168.3.120/24
            routes:
                - to: default
                  via: 192.168.3.1
            nameservers:
                addresses:
                    - 8.8.8.8
                    - 8.8.4.4
            optional: true

ubuntu server 20.04 connect to wifi

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network:
    version: 2
    ethernets:
        eth0:
            dhcp4: true
            optional: true
    wifis:
        renderer: networkd
        wlan0:
            dhcp4: no
            addresses:
                - 192.168.3.119/24
            routes:
                - to: default
                  via: 192.168.3.1
            nameservers:
                addresses:
                    - 8.8.8.8
                    - 8.8.4.4
            access-points:
                "gl":
                    password: "4da86c9782081b654f1cca03590bebf374da6084aad4c2e471aa99cdb33a144f"
            optional: true

树莓派(Raspberry Pi) 设置静态IP/连接Wi-Fi

安装ros2相关工具

• 二进制安装foxy
• 源码安装foxy

目前humble有点问题，所以装foxy，可以的镜像是ubuntu-20.04.5-preinstalled-server-armhf+raspi.img.xz。

初始化项目

登录开发机。

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mkdir ~/code/dev_ws/src -p
cd ~/code/dev_ws/src
git clone git@github.com:joshnewans/my_bot.git
cd ..
colcon build --symlink-install

launch

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cd ~/code/dev_ws/
source install/setup.bash
ros2 launch my_bot rsp.launch.py