pi4 0.5.0

Raspberry Pi Applications.

pi - Raspberry (Raspberry Pi 4B) related codes

OS : raspbian 64-bit.

Development on pi is quite comfortable. It is essentially linux-based app development, with some GPIO/I2C/SENSOR programmings.

Vehicle

The GUI uses ttkbootstrap, tkinter, pyqt, opencv etc.

vehicle acc (adaptive cruise control)

* The vehicle has a supersonic sensor, short-distance collision detection sensors, fall detection sensor and a pan-tilt-mounted infra-red camera.  
* The vehicle currently USED PINS:

3V3  (1) (2)  5V    
- GPIO2 PCA9685 SDA (3) (4)  5V    
- GPIO3 PCA9685 SCL (5) (6)  GND   
- GPIO4 IR Control (7) (8)  - GPIO14 UART TX
GND  (9) (10) - GPIO15 UART RX
* GPIO17 (11) (12) - GPIO18
- GPIO27 (13) (14) GND   
- GPIO22 (15) (16) - GPIO23
3V3 (17) (18) - GPIO24
* GPIO10 SPI (19) (20) GND   
* GPIO9 SPI (21) (22) - GPIO25
* GPIO11 SPI (23) (24) * GPIO8 SPI0 CE0
GND (25) (26) * GPIO7 SPI0 CE1
- GPIO0 (27) EEPROM SDA (28) - GPIO1 EEPROM SCL | CAT24C32: EEPROM 串行 32-Kb I2C
- GPIO5 (29) (30) GND   
- GPIO6 (31) (32) - GPIO12
- GPIO13 (33) (34) GND   
- GPIO19 (35) (36) - GPIO16
- GPIO26 (37) (38) - GPIO20
GND (39) (40) - GPIO21

demo video

Medical Device

* This is a 4b-based medical device prototype. The GUI provides camera liveview, image capturing, browsing, uploading.

IOT

Raspberry pi-based iot experiments code.

Some sensors can be replaced by other types. e.g., touch sensor -> tilt / vibration / reed / push button.

With the i2c chip (8591), you can use analog output sensors, such as joystick, raindrop, smog, flame, thermo-resistor, photo-resistor, noise, etc.

edge-computing and AI

This package also include an 'ai' module. The module is mainly targeted at edge devices (largely depends on tf-lite, efficientnet, mobilenet and other lightweight models or frameworks). However, it can also be used for general-purposed ai and image processing applications.

Communication with Arduino

src/arduino/draw/draw.ino is an arduino drawing board application.

src/pi/draw/host.py is its upper control GUI. The GUI allows to open a gcode file and send gcode commands to arduino by serial, I2C or bluetooth.

src/arduino/4wd/4wd.ino is another arduino project (supports IR remote control):

src/pi/4wd/control.py is its upper control GUI (by bluetooth):

Setup the raspberry pi os

0. Use the official Raspi Imager tool to setup Raspbian 64 bit OS to SD card

1. If you haven't configured wifi in Raspi Imager, create the wpa_supplicant.conf file in boot folder:

country=CN update_config=1 ctrl_interface=/var/run/wpa_supplicant

network={ scan_ssid=1 ssid="2701" # wifi name psk="xxx" # password priority=1 }

2. create an empty file named ssh in boot folder.

3. Boot device

4. Use the wireless router's admin panel to check the pi's ip:

SSID1 raspberrypi 192.168.5.xxx e4:5f:01:9c:1b:c4

5. ssh [e-mail]

   The authenticity of host '192.168.5.120 (192.168.5.120)' can't be established. ECDSA key fingerprint is SHA256:Qj+rFMb4dTkKNh6SeADd30S9KK8N1mSyTvKFqSEq8M4. Are you sure you want to continue connecting (yes/no/[fingerprint])? y Please type 'yes', 'no' or the fingerprint: yes Warning: Permanently added '192.168.5.120' (ECDSA) to the list of known hosts. pi@192.168.5.120's password: Linux raspberrypi 5.15.32-v7l+ #1538 SMP Thu Mar 31 19:39:41 BST 2022 armv7l

   pinout

   pi@raspberrypi:~ $ pinout ,--------------------------------. | oooooooooooooooooooo J8 +====== | 1ooooooooooooooooooo PoE | Net | Wi 1o +====== | Fi Pi Model 4B V1.5 oo | | ,----. +---+ +==== | |D| |SoC | |RAM| |USB3 | |S| | | | | +==== | |I| ----' +---+ | | |C| +==== | |S| |USB2 | pwr |hd| |hd| |I||A| +==== -| |---|m0|---|m1|----|V|-------'

6. pi@raspberrypi:~ $ raspi-config

   Enable VNC in the interface settings Change VNC resolution to 1280x720 in the display settings. (to enhance response speed) Expand SD storage. then df-h to check

7. Connect SPI screen and reboot

   If wifi is disabled, the SPI screen will show; otherwise use ssh, VNC or Teamviewer.

   sudo nano /boot/config.txt

   Uncomment the dtoverlay=vc4-kms-v3d

   sudo reboot

8. Connect SPI camera

   libcamera-hello [OBSOLETE] > sudo raspistill -o myimg.jpg

9. Plugin the camera and test

   sudo apt-get update && sudo apt-get upgrade sudo apt-get install fcitx fcitx-googlepinyin # optional: install IME

   sudo apt-get install luvcview luvcview # a live view of /dev/video0

   sudo apt install fswebcam fswebcam -r 1600x1200 --rotate 180 --no-banner image1.jpg # capture image

10. update eeprom: this helps to reduce CPU temperature

    sudo rpi-eeprom-update -a
    sudo reboot

11. Install numpy and opencv

    [Optional] When the network speed is unbearable )NOTE: The file content for 32 and 64 bit OS differ):

    sudo nano /etc/apt/sources.list
    sudo nano /etc/apt/sources.list.d/raspi.list
    Replace deb and deb-src with domestic mirrors. e.g., http://mirrors.tuna.tsinghua.edu.cn/raspberrypi/ bullseye ...

    sudo pip install --upgrade cmake numpy opencv-python opencv-contrib-python -i https://pypi.tuna.tsinghua.edu.cn/simple

12. WringPi

    64bit: wget https://github.com/WiringPi/WiringPi/releases/download/2.61-1/wiringpi-2.61-1-arm64.deb

    or

    32bit: wget https://github.com/WiringPi/WiringPi/releases/download/2.61-1/wiringpi-2.61-1-armhf.deb

    sudo dpkg -i wiringpi-latest.deb gpio -v gpio readall

13. Setup GPIOZero and/or RPi.GPIO

    sudo apt install python3-gpiozero
    gpiozero can be simpler than RPi.GPIO and more friendly to beginners.
    The gpiozero module always uses Broadcom GPIO numbering to identify a GPIO.
    The RPi.GPIO module can use physical pin numbering (BOARD) or Broadcom GPIO numbering (BCM). The physical pin 21 is connected to GPIO 9.

14. I2C device setup

    gpio i2cdetect

        0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
    00:                         08 -- -- -- -- -- -- -- 
    10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
    20: -- -- -- -- -- -- -- 27 -- -- -- -- -- -- -- -- 
    30: -- -- -- -- -- -- -- -- -- -- -- -- 3C -- -- -- 
    40: 40 41 -- -- -- -- -- -- 48 -- -- -- -- -- -- -- 
    50: -- -- -- -- -- -- -- 57 -- -- -- -- -- -- -- -- 
    60: -- -- -- -- -- -- -- -- 68 -- -- -- -- -- -- -- 
    70: 70 -- -- -- -- -- -- --   

0x08 - Arduino drawing board  
0x27 - LCD1602 PCF8574  
0x3C - TTP 229 16-key touch pad | 0.96" inch OLED screen   
0x40 - servo: PCA9685 16-channel PWM driver  
0x41 - 6WD control board    
0x48 - ADC: PCF8591  
0x57 - SpO2 sensor  
0x68 - XYZ sensor  
0x70 - 

I2C is not hot-pluggable. You must restart to add a new I2C device.  

To check a full list of I2C addresses, go to https://i2cdevices.org/addresses

14. Bluetooth SPP

    Connect HC06's TX and RX to Arduino's RX and TX.

    hciconfig hci0: Type: Primary Bus: UART BD Address: E4:5F:01:9C:1B:C5 ACL MTU: 1021:8 SCO MTU: 64:1 UP RUNNING PSCAN RX bytes:4889 acl:0 sco:0 events:158 errors:0 TX bytes:3783 acl:0 sco:0 commands:127 errors:0

    hcitool scan Scanning ... 98:DA:40:01:78:68 HC-06

    sudo killall rfcomm

    sudo rfcomm connect /dev/rfcomm1 98:DA:40:01:78:68 &
    Connected /dev/rfcomm1 to 98:DA:40:01:78:68 on channel 1

    ls /dev/rfcomm*

    sudo apt-get install picocom
    sudo picocom -c /dev/rfcomm0

    Then, use it as a regular serial port '/dev/rfcomm1'.

15. Bluetooth GUI

    sudo apt install bluetooth pi-bluetooth bluez blueman
    Then you can connect to bluetooth speakers, etc.

16. [Optional] Setup ir (infra-red). This is the most painful part. Take patience.

sudo apt install lirc liblircclient-dev ir-keytable # lirc: Linux Infrared Remote Control

sudo nano /boot/config.txt
dtoverlay=gpio-ir,gpio_pin=17 #4
dtoverlay=gpio-ir-tx,gpio_pin=18 #5 

sudo reboot

pi@raspberrypi:~ $ sudo ir-keytable -c -p all -t
Old keytable cleared
Protocols changed to unknown other lirc rc-5 rc-5-sz jvc sony nec sanyo mce_kbd rc-6 sharp xmp cec imon rc-mm 
Loaded BPF protocol xbox-dvd
Testing events. Please, press CTRL-C to abort.

[press some key on the remote controller]

237.470055: lirc protocol(nec): scancode = 0x45
237.470076: event type EV_MSC(0x04): scancode = 0x45
237.470076: event type EV_SYN(0x00).
237.530059: lirc protocol(nec): scancode = 0x45 repeat
237.530079: event type EV_MSC(0x04): scancode = 0x45
237.530079: event type EV_SYN(0x00).
238.790052: lirc protocol(nec): scancode = 0x46
238.790071: event type EV_MSC(0x04): scancode = 0x46
238.790071: event type EV_SYN(0x00).


sudo nano /etc/lirc/lirc_options.conf

driver = default
device = /dev/lirc1

pi@raspberrypi:~ $ sudo systemctl stop lircd.service
Warning: Stopping lircd.service, but it can still be activated by:
lircd.socket
pi@raspberrypi:~ $ sudo mode2 -d /dev/lirc1
[Press some keys on the remote controller]
Using driver default on device /dev/lirc1
Trying device: /dev/lirc1
Using device: /dev/lirc1
Running as regular user pi
pulse 9071
space 4471
pulse 608
space 519
pulse 589
...

把lircd.conf 传到pi目录下；
sudo cp lircd.conf /etc/lirc/lircd.conf

sudo reboot


pi@raspberrypi:~ $ irw
0000000000000001 00 KEY_CHANNELDOWN ./lircd.conf
0000000000000002 00 KEY_CHANNEL ./lircd.conf
0000000000000008 00 KEY_VOLUMEDOWN ./lircd.conf
0000000000000007 00 KEY_VOLUMEUP ./lircd.conf

17. Enable 1 Wire

enable "1 wire" and add "dtoverlay=w1-gpio" to /boot/config.txt

reboot

Connect the 1-wire temperature sensor

pi@raspberrypi:/sys/bus/w1/devices/28-012029342a03 $ cat w1_slave
c2 01 4b 46 7f ff 0c 10 a8 : crc=a8 YES
c2 01 4b 46 7f ff 0c 10 a8 t=28125
pi@raspberrypi:/sys/bus/w1/devices/28-012029342a03 $ cat w1_slave
c2 01 4b 46 7f ff 0c 10 a8 : crc=a8 YES
c2 01 4b 46 7f ff 0c 10 a8 t=28125

18. ap

git clone https://github.com/oblique/create_ap.git  
cd create_ap  
sudo make install  
sudo apt-get install dnsmasq  
sudo apt-get install util-linux procps hostapd iproute2 iw haveged  

sudo create_ap wlan0 eth0 热点名 密码

optional:   
sudo nano /etc/rc.local   
add create_ap ...  

19. GUI dev: ttkbootstrap, webview, qt

[gtk backend for webview] > sudo apt install python3-gi python3-gi-cairo gir1.2-gtk-3.0 gir1.2-webkit2-4.0   
[optional if use qt backend for webview] > sudo apt install python3-pyqt5 python3-pyqt5.qtwebengine python3-pyqt5.qtwebchannel libqt5webkit5-dev   

> sudo pip install ttkbootstrap pywebview -i https://pypi.tuna.tsinghua.edu.cn/simple

> sudo apt-get install qtbase5-dev qtchooser qt5-qmake qtbase5-dev-tools qtcreator qtdeclarative5-dev  

20. [Optional] Data Science

    sudo apt-get install r-base r-base-dev
    sudo pip install sklearn

    if you want to do some deep learning,
    sudo pip install Cython==0.29.16
    go to https://github.com/Qengineering/TensorFlow-Raspberry-Pi_64-bit to download a correct whl
    sudo pip install tensorflow-2.9.1-cp39-cp39-linux_aarch64.whl
    sudo pip install keras
    sudo pip install torch-1.11.0a0+gitbc2c6ed-cp39-cp39-linux_aarch64.whl

    if you want to C/C++ programming, do the following:

    sudo apt-get install libopencv-dev # codeblocks    
    add /usr/include/opencv4/ to 'search directories'
    
    wget https://github.com/tensorflow/tensorflow/archive/v2.6.5.zip   
    unzip  
    ./tensorflow/lite/tools/make/download_dependencies.sh  
    ./tensorflow/lite/tools/make/build_aarch64_lib.sh  
    
    According to https://qengineering.eu/install-tensorflow-2-lite-on-raspberry-64-os.html, we need to compile newer version of flatbuffers:  
    cd tensorflow/lite/tools/make/downloads  
    rm -rf flatbuffers  
    git clone -b v2.0.0 --depth=1 --recursive https://github.com/google/flatbuffers.git  
    cd flatbuffers && mkdir build && cd build && cmake .. && make -j4  
    sudo make install && sudo ldconfig  
    

21. Customize splashscreen

    nano /boot/cmdline.txt
    console=serial0,115200 console=tty1 root=PARTUUID=ae28fe49-02 rootfstype=ext4 fsck.repair=yes rootwait quiet splash plymouth.ignore-serial-consoles console=tty3 logo.nologo loglevel=3 vt.global_cursor_default=0 plymouth.enable=0

    Plymouth is the application which provides the graphical "splash" screen when booting and shutting down an Ubuntu system.

    nano /boot/config.txt
    disable_splash=1

    sudo apt install fbi
    sudo nano /etc/systemd/system/splashscreen.service

    [Unit] Description=Splash screen DefaultDependencies=no After=local-fs.target [Service] ExecStart=/usr/bin/fbi -d /dev/fb0 --noverbose -a /home/pi/your_image.jpg StandardInput=tty StandardOutput=tty [Install] WantedBy=sysinit.target

    sudo systemctl enable splashscreen

Install

pip install pi4

Run

IoT GUI: `sudo python -m pi.iot.vehicle`

Camera GUI: `sudo python -m pi.camera.ttk`

AI GUI: `sudo python -m pi.ai.demo`

If you run under Windows, the native GPIO and SMBus will be replaced by a simulator.

    if sys.platform == 'win32':
        sys.path.append(os.path.dirname(__file__))
        from simulator import GPIO, SMBus, PWM
    else:
        from RPi import GPIO
        from smbus import SMBus

Autostart

If you need to autostart a GUI app,

> sudo nano /etc/xdg/autostart/picam.desktop
           
[Desktop Entry]
Name = PiCam
Exec=/usr/bin/python3 -m pi.camera.ttk

Create a Shrinked Image

Use Win32DiskImager to create a full-sized image.  
Download pishrink.sh from https://github.com/Drewsif/PiShrink.    

chmod +x pishrink.sh  
sudo mv pishrink.sh /usr/local/bin  

sudo pishrink.sh pi.img  # to restore, use etcher.