Joy PI Experimental and Education Case

Experimental and education case
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1. TABLE OF CONTENT
1. Table of content 2. General information & saftey instructions 3. Details 4. Commissioning & operation 5. Changing modules and using the GPIOs 6. Usage of Python and Linux 7. Lessons
1. Lesson : Using the buzzer for warning sounds 2. Lesson : Controlling the buzzer with key inputs 3. Lesson : How a relay is working and how to control it 4. Lesson : Sending a vibration signal 5. Lesson : Detecting noises with the sound sensor 6. Lesson : Detecting brightness with the light sensor 7. Lesson : Detecting the temperature and the humidity 8. Lesson : Detecting movements 9. Lesson : Measuring distances with the ultrasonic sensor 10. Lesson : Controlling the LCD display 11. Lesson : Reading and writing RFID cards 12. Lesson : Using stepper motors 13. Lesson : Controlling servo motors 14. Lesson : Controlling the 8 x 8 LED matrix 15. Lesson : Controlling the 7 segment display 16. Lesson : Detecting touches 17. Lesson : Detecting tilts with the tilt sensor 18. Lesson : Using the button matrix 19. Lesson : Controlling and using the IR sensor 20. Lesson : Own circuits with the breadboard 21. Lesson : Photographing with the Raspberry Pi camera 8. Other information 9. Copyright information 10. Support
The login data is: Username : pi Password : 12345
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2. GENERAL INFORMATION & SAFETY INSTRUCTIONS Dear customer, Thank you very much for choosing our product. In the following, we will show you what has to be observed during commissioning and use. Should you encounter any unexpected problems during use, please feel free to contact us. The following lessons are designed so that, regardless of how much prior knowledge you already have, you can complete all lessons without any problems. For the different lessons, you have to download sample files and run them on the Joy-Pi. How to do this can also be found in this manual. But these tutorials are only the beginning you can use your Joy-Pi for a variety of projects. We are looking forward to see what you will do with our Joy-Pi.
Safety instructions
1. This device is intended for use in dry indoor areas. It must not become wet or damp! Also do not touch the device with wet hands!
2. The permissible ambient temperature is : 5 – 40 °C 3. Do not expose the device to direct sunlight, as the Joy-Pi could heat
up by this. 4. If the unit is damaged or has faults, do not longer use it and contact
our service for further instructions 5. Unplug the power supply from the power outlet if you are not going
to use it for a longer period of time. 6. Handle this product with care. It must not contain high exposed to
temperature, humidity or pressure. It may not be short-circuit either.
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3. DETAILS

1 2 3 4 5 6 7 8 9 10 11 12 13 14 / 15

Raspberry Pi GPIO LED display
Breadboard 16 x 2 LCD module (MCP23008)
Power supply 8 x 8 LED matrix (MAX7219) 7 segment LED display(HT16K33)
Vibration module Light sensor (BH1750)
Buzzer Sound sensor Motion sensor (LH1778) Ultrasonic distance sensor Servo interfaces
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16

Stepper motor interface

17

Tilt sensor (SW-200D)

18

Infrared sensor

19

Touch sensor

20

DHT11 temperature and humidity sensor

21

Relay

22

Key matrix

23

Independent keys

24

RFID module (MFRC522)

25

Switch

26

Fan connection

27

Power supply microUSB

4. COMMISSIONING & OPERATION First you must insert your microSD card into the slot provided by the Raspberry Pi. If you do not want to use our image, please read chapter 5.3 and chapter 6.1 to create your own image. Now you can wire the Raspberry Pi to the Joy-Pi. For this purpose plug the AUX adapter into the AUX port and the USB cable into one of the USB ports. Then connect both GPIO bars, one from the Raspberry Pi and one from the Joy-Pi with the supplied cable. With the HDMI cable, please note that you may need to replace the HDMI adapter depending on the Raspberry Pi you are using. For the Raspbbery Pi 4 you need the small micro HDMI adapter, for all older Raspberry Pi models you need the big HDMI adapter. Changing the adapter is done quickly. Pull the plastic lock of the connector carefully downwards to release the HDMI cable, as shown by the arrows in the picture below. Now you can simply pull the cable out of the adapter.

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Now take the other HDMI adapter and, as in the previous step, carefully pull the plastic latch of the connector downwards to release the lock. Now you can plug the HDMI cable into the connector. Make sure that the side of the cable with the silver contacts, as shown in the picture below, points away from the adapter.
When the cable is fully inserted into the connector, you can close the lock by carefully pushing the plastic latch of the connector upwards.
Now you can plug the HDMI cable into your Raspberry Pi and screw the Raspberry Pi firmly onto the board of the JoyPis. To start the Joy-Pi, all you have to do is to supply it with power. The power cable which is included, should be connected on the right side of the board. The Joy-Pi should now start as soon as you flip the switch on the power cord.
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You have various possibilities to operate your Joy-Pi. One is via the wireless keyboard, which can be used in combination with the touch display, or you can provide a connection to your computer using VNC or SSH.
Wireless keyboard
First, connect the USB stick of the keyboard to one of your USB ports of the Raspberry Pi. Now you can switch it on at the right side of the keyboard and with the help of the key combination Fn+RF it will connect to the Joy-Pi. In order to make the key assignment match the German keyboard layout of the keyboard, German must be selected as language in the system preferences. To do this, open the terminal and enter the following command to open the system settings: sudo raspi-config There you select 4 Localisation Options I1 Change Locale to select German as language. There is also a touchpad on the keyboard that you can use to move the cursor. Further functions are described in the enclosed instructions. The enclosed microUSB cable is intended for charging the keyboard.
VNC
With the help of the program VNC Viewer, which you can download here. With this program, you can see the desktop of your Joy-Pi on your computer and you can operate it completely. To use this function you must first allow a VNC connection. You enable this in the system settings. To do this, execute the following command: sudo raspi-config There you activate VNC in 5 Interfacing Options P3 VNC. Now you can connect to the Raspberry Pi via your network. To do so, enter the IP address of the Joy-Pi. You can see the IP address of the Joy-Pi by clicking on the VNC sign in the upper right corner. Now you only have to login with the login data and then you have fully access from your computer to your Joy-Pi.
user name : pi password : 12345
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SSH
SSH is a different connection path than VNC to connect wirelessly to your Joy- Pi from a PC. You can use for example MobaXTerm, which you can download here. To be able to establish an SSH connection, you must enable SSH and your Joy-Pi must be connected to your network. Enable SSH in system preferences 5 Interfacing Options P2 SSH. Open system preferences with: sudo raspi-config

Now click you enter

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a new connection. There IP address can be dis-

played by clicking on the VNC icon in the upper right corner.

user name : pi password : 12345

You must then enter the password. Attention! It is possible that the keystrokes are not displayed when entering the password. Now, you can see a terminal which can control the Joy-Pi.

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5. CHANGING MODULES AND USING THE GPIOS
5.1 Change of modules

On the Joy-Pi board there are two switching units with 8 switches each. The switches make it possible to switch between different sensors and modules. Since the Raspberry Pi has only a limited number of GPIO pins, these switches are needed to use more sensors and modules than GPIO pins are available. Using these switches is quite simple and will be needed in some of the following lessons. In the table you can see which switch switches which sensor or module.

Sensors / modules Key matrix
Independent keys Vibration module
Tilt sensor Stepper motor Servo motor

Switching unit Left Left Right Right Right Right

Keys 1 – 8 5 – 8
1 2 3, 4, 5, 6 7, 8

5.2 Usage of GPIOs
In the following we will explain in more detail what GPIO’s are, how they work and how they are controlled.

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GPIO stands output).

for:

General

–

purpose

input

/

output

(universal

input

/

GPIO pins do not have a specific purpose. They can be configured as ei-

ther input or output and have a general purpose. This depends on what

you want to achieve.

Example input pin: Button If the button is pressed, the signal will be transferred through the input pin of the Raspberry Pi.

Example output pin: Buzzer A signal will be sent via the output pin of the Raspberry Pi to the buzzer to control it.

If you look on the opened Joy-Pi from the front, the GPIO pins will be on the right side of the Raspberry Pi.

There are 2 possible schemata of the Raspberry Pi GPIO: GPIO – BOARD and GPIO – BCM. The GPIO – BOARD schemata that reference pins via the actual pin number. That means that the pin numbers of the following picture is used.

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the pins GPIO:

reference

Broadcom

SOC

1

3.3 V DC

2

3

GPIO 2 (SDA1, I2C)

4

5

GPIO 3 (SCL1, I2C)

6

7

GPIO 4

8

9

Ground

10

11

GPIO 17

12

13

GPIO 27

14

15

GPIO 22

16

17

3.3 V

18

19

GPIO 10 (SPI, MOSI)

20

21

GPIO 9 (SPI, MISO)

22

23

GPIO 11 (SPI, CLK)

24

25

Ground

26

27

ID_SD (I2C, EEPROM)

28

29

GPIO 5

30

31

GPIO 6

32

33

GPIO 13

34

35

GPIO 19

36

37

GPIO 26

38

39

Ground

40

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5 V DC 5 V DC Ground GPIO 14 (TXD0) GPIO 15 (RXD0) GPIO 18 Ground GPIO 23 GPIO 24 Ground GPIO 25 GPIO 8 (SPI) GPIO 7 (SPI) ID_SC Ground GPIO 12 Ground GPIO 16 GPIO 20 GPIO 21

GPIO – BOARD 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
27
28 29 30 31 32
33
34
35
36 37 38 39 40

Sensors and modules 3.3 V 5.0 V
I2C, SDA1 (Light sensor, LCD display, 7 segment display) 5.0 V
I2C. SCL1 (Light sensor, LCD display, 7 segment display) Ground
DHT11 sensor TXD0
Ground RXD0 Touch sensor Buzzer Button matrix(ROW1), vibration motor Ground Button matrix (ROW2), tilt sensor Motion sensor 3.3 V Sonic sensor SPI Ground SPI Servo2, Button matrix (COL1), left button SPI RFID module Ground LED matrix ID_SD (I2C, EEPROM (Electrically Erasable Programmable Read – only Memory)) ID_SC Stepper motor (STEP1), button matrix (ROW3) Ground Stepper motor (STEP2), button matrix (ROW4) Ultrasonic sensor (Echo) Stepper motor (STEP3), button matrix(COL4), down button Ground Stepper motor (STEP4), button matrix (COL3), right button Ultrasonic sensor (TRIG) Servo1, button matrix (COL2), up button Infrared sensor Ground Relay
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In our examples, we use the programming language Python to control the GPIO pins. In Python exists a library which is known as RPi.GPIO. This library is necessary to control the pins with Python.

The following example and comments in the code should help you to understand the program.

First, you have to import the required library with the import command.

The variable TOUCH and BUZZER references to the pins of the touch

sensor and the buzzer. Afterwards, you define the connection with

GPIO.setmode(GPIO.BOARD) as the used GPIO schemata. As the next

step, you configurate the earlier set variables with the command

GPIO.setup() as input or rather output. Pin 11 (TOUCH) is set as input and

pin 12 (BUZZER) as output.

The main function queries if a touch has been detected by the touch sen-

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will be executed. and sets the buzzer

HIGH

and one second later LOW again(buzzer will sum one second):

import RPi.GPIO as GPIO import time #import libraries import signal
TOUCH = 11 #declaring variables BUZZER = 12
def setup_gpio(): #definition of inputs and outputs GPIO.setmode(GPIO.BOARD) GPIO.setup(TOUCH, GPIO.IN, pull_up_down=GPIO.PUD_UP) GPIO.setup(BUZZER, GPIO.OUT)
def do_smt(channel): #function for the output if touch was dected print(“Touch detected”) #and output that touch was detected GPIO.output(BUZZER, GPIO.HIGH)

signal output time.sleep (1) #wait 1 second GPIO.output(BUZZER, GPIO.LOW)

stop signal output

def main(): setup_gpio() try: #checking if touch is detected GPIO.add_event_detect(TOUCH,GPIO.FALLING,callback=do_smt,bouncetime=200) except KeyboardInterrupt: #CTRL + C exists the script pass finally: GPIO.cleanup()
if name==_main_: main()

To learn more about the purpose and usage of GPIO, we recommend that you read the official documentation on that topic of GPIO pins which is written by the Raspberry Pi Foundation. https://www.raspberrypi.org/documentation/usage/gpio/

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5.3 Software installation for the Joy-Pi
On the included microSD card is a preinstalled operating system already installed. If you want to rewrite the card, you can do it like described in the following: First of all, you should download the latest image file for the Joy-Pi from our website www.joy-pi.net. 1. Download the image file (.zip format). After
unzipping the file, you get a file that ends with .img. 2. Connect your microSD card to your computer and format it with
the program SD formatter. A microSD card reader is included in the scope of delivery. 3. Start the program Win32-Disk-Imager and choose the downloaded image file. the device which is to be written. 4. Now the card is written with the operating system and you can insert it into the microSD card slot of the Raspberry Pi.

5. At the end, you have to edit the image to the size of your SD card.

Therefore, start the Raspberry Pi, open the terminal and enter

sudo raspi-config.

Click After

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card.

6. USAGE OF PYTHON AND LINUX
6.1 Download of code examples
This step is optional but it makes it easier to execute scripts without having to create them individually. On our prepared image for the Joy-Pi all code examples are already downloaded. So all scripts are already on the desktop. The scripts which are used in this guide can be downloaded directly from a package. Therefore, follow the following instructions:

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1. Open the Terminal. We will need this to perform most of our Python scripts and to download scripts and expansions.
2. After we have successfully opened the terminal, we need to download the script archive to the desktop (included on the image) using the following command
cd Desktop/ wget https://joy-pi.net/wp-content/uploads/2020/09/Joy-Pi.zip 3. Press Enter on your keyboard. Now you have to unzip the archive: unzip Joy- Pi.zip 4. Press Enter again on your keyboard and wait until the process
succeeded. 5. With the command cd, you can change to the right folder to be able
to use the scripts which are placed there: cd Joy-Pi
Attention! Every time you shut down your Joy-Pi, you must repeat these steps to change the folder.
The login data is: Username : pi Password : 12345
6.2 Installation of the required libraries
If you are not using our prepared image, you can install the required libraries as follows:
16×2 LCD
For the 16×2 LCD the library Adafruit_CircuitPython_CharLCD from adafruit is used. Enter the following command into the terminal for the installation: sudo pip3 install adafruit-circuitpython-charlcd
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Segment Anzeige
For the segment display the library Adafruit_CircuitPython_HT16K33 from adafruitis used. Enter the following commands into the terminal for the installation: sudo apt-get install python3-pip sudo apt-get install python3-pil sudo pip3 install adafruit-circuitpython-ht16k33
LED-Matrix
For the LED matrix the library luma.led_matrix from rm-hull is used. Enter the following command into the terminal for the installation: sudo wget https://github.com/rm-hull/luma.led_matrix/ archive/refs/heads/master.zip Now extract the downloaded archive: sudo unzip master.zip Now navigate to the library folder and edit the setup.cfg file with the following commands: cd luma.led_matrix-master sudo nano setup.cfg Now remove the following line from the file: ws2812; platform_machine==”armv7l” and platform_system==”Linux” Save the changes with Ctrl + O and close the file with Ctrl + X. After that you can install the library with the following command: sudo pip3 install ­e .
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RFID-MFRC522
For the RFID Module the library MFRC522-python from lucassarcanjo is used. Furthermore the library SPI-Py from lthiery is required. Enter the following commands into the terminal for the installation:
sudo git clone https://github.com/lthiery/SPI-Py.git
cd SPI-Py/
sudo python3 setup.py install
sudo git clone –single-branch –branch python3-spi-updates https:// github.com/lucassarcanjo/MFRC522-python.git Note that also the last command must be entered as just one line.
IR-Sensor
For the IR-Sensor the library IR-Remote-Receiver-Python-Module from owainm713 is used. Enter the following commands into the terminal for the installation: sudo git clone https://github.com/owainm713/IR-RemoteReceiver-Python- Module.git You can save the file IRModule.py in your library folder under “/usr/lib/ python3.7/IRModule.py”. This allows you to run the sample script from any folder. You can use this command to do this: sudo mv /home/pi/IR- Remote-Receiver-Python-Module/ IRModule.py /usr/lib/python3.9/IRModule.py
DHT11
For the DHT11 the library DHT11_Python from szazo is used. Enter the following command into the terminal for the installation:
sudo pip3 install Adafruit_DHT
6.3 Performing Python scripts
After we successfully downloaded our script, we would like to execute it. Open the terminal again and follow the instructions below to run the script: 1. Enter the command sudo python3