RaspberryPiSetup

Raspberry Pi 3 Quick Start Guide

Transfer image to microSD card

Mac: Unmount card's partition first, e.g. /dev/rdisk4s1 by launching Disk Utilities, then click boot partition then click Unmount.

sudo dd bs=1m if=2020-02-13-raspbian-buster-full.img of=/dev/rdisk4 conv=sync

Fix laggy mouse pointer (Microsoft keyboard with touchpad)

Add usbhid.mousepoll=0 to /boot/cmdline.txt

sudo nano /boot/cmdline.txt to open

CTRL+O to wrie-out changes, Enter to confirm

CTRL+X to exit Nano editor.

Disable screensaver

sudo apt-get install xscreensaver and disable using xscreensaver's UI

Flip image vertically

In /boot/config.txt, add lcd_rotate=2

Adjust 7" Touchscreen Brightness

Open /sys/class/backlight/rpi_backlight/brightness and modify integer value, 0-255

Update Raspbian

First, update your system's package list by entering the following command:

sudo apt-get update

Next, upgrade all your installed packages to their latest versions with the command:

sudo apt-get dist-upgrade

Clear downloaded package files (.deb files) in /var/cache/apt/archives:

sudo apt-get clean

Make terminal alias

In home directory: nano .bashrc

Add: alias ll='ls -lah'

Edit 7" touchscreen backlight 'file' permission

Edit the backlight rules file: sudo nano /etc/udev/rules.d/backlight-permissions.rules

Insert line: SUBSYSTEM=="backlight",RUN+="/bin/chmod 666 /sys/class/backlight/%k/brightness /sys/class/backlight/%k/bl_power"

Automatic backlight brightness change by Cds sensor

Code:

from gpiozero import LightSensor
from time import sleep
offset = 15
max = 255
min = 15
prev = 0
delta = 0
f = open('/sys/class/backlight/rpi_backlight/brightness', 'w')
sensor = LightSensor(18, charge_time_limit=0.2, threshold=0.1)
while True:
    print("Sensor value: ", sensor.value)
    lightValue = round(255 * sensor.value + offset)

    if lightValue > max:
        lightValue = max
    if lightValue < min:
        lightValue = min
    print("Light value: ", lightValue)
    delta = abs(lightValue - prev)
    if delta > 1:
        print("Delta: ", abs(lightValue - prev))
        prev = lightValue
        f.seek(0)
        f.write(str(lightValue))
        f.truncate()
    sleep(1)

Enable autorun of autobrightness.py on boot, by making it a systemd service

In /etc/systemd/system Make autobrightness.service file.

Put in following:

[Unit]
Description=Get auto brightness service running at boot
After=mosquitto.service mysql.service

[Service]
ExecStart=/usr/bin/python3 /home/pi/autobrightness/autobrightness.py
Restart=always
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=autobrightness
User=pi
Group=pi

[Install]
WantedBy=multi-user.target

Enable service:

sudo systemctl enable autobrightness.service

Start clock for current boot only:

sudo systemctl start autobrightness.service

Check if it's running:

systemctl status autobrightness.service

GPIO Diagnostics Routine - change pin number to desired pin, and either source or sink an LED with 10K resistor. LED should blink:

import RPi.GPIO as GPIO
import time

pin = 18

GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
GPIO.setup(pin,GPIO.OUT)
while True:
        print(pin,"HIGH")
        GPIO.output(pin,GPIO.HIGH)
        time.sleep(0.5)
        print(pin,"LOW")
        GPIO.output(pin,GPIO.LOW)
        time.sleep(0.5)

dandydanny/RaspberryPiSetup