Raspberry pi Notes

raspberry_pi_notes_1.md

Setting Raspbery pi zero for wifi

• setting up tutorial
• Download Raspbian lite
• Flash Raspbian lite zip file into SD card using etcher software
• If SD card is showing wrong capacity or shown as 2 disks, goto device management and delete all partitions of sd card, create new simple volumn of type FAT32. Even then, if etcher could not flash raspbian, try using another laptop.
• save a file named ssh (no extension) in the sd card
• write the following in a file named wpa_supplicant.conf and save it in the sd card

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

 
network={
    ssid="WIFI-NAME"
    psk="WIFI-PASSWORD"
    scan_ssid=1
}

• use Advanced IP Scanner to find the ip address of raspberry pi.
• use PuTTY to connect to raspberry pi ssh terminal. Port is 22, connection type is SSH.
• Putty login and password credentials are pi and raspberry (default password).
• To transfer files from your pc to raspberry pi use WinSCP software.

Running python flask webserver in raspberry pi

• Link for code - https://github.com/adafruit/Pi_Internet_Thing_Videos/tree/master/Part_1
• Install python and flask in raspberry pi by typing the following 3 commands in putty after logging into the pi.

sudo apt-get update
sudo apt-get install -y python3
sudo apt-get install -y python-pip3 python3-dev
sudo pip3 install flask

• Transfer files from your PC to raspberry pi connected in the same wifi using winscp
• After transfering the files, you can verify the presence of files in putty using ls command
• To run the web server, use the standard command like python main.py

GPIO Pins

• Raspberry Pi zero w layout diagram -
• GPIO pins should be given voltages not above 3.3 V and currents not more than 0.5mA. If we use a 3.3 V power source, use resistor of atlease 6 KOhms - link