Raspberry Pi Notes

Installation
============
Cek microSD card
$ lsblk

Unmount
$ umount /dev/sdb1

Install
$ unzip -p 2018-04-18-raspbian-stretch.zip | dd bs=4M of=/dev/sdX status=progress conv=fsync
$ sync

Now go to the SD card /boot
$ cd /media/gungsukma/boot

$ touch ssh
$ nano wpa_supplicant.conf
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
network={
    ssid="YOUR_NETWORK_NAME"
    psk="YOUR_PASSWORD"
    key_mgmt=WPA-PSK
}

Okay. Installation finished.

Setup
- Ubah password, aktifkan WiFi
- Aktifkan kamera, SSH, serial, remote GPIO
- Pilih timezone, keyboard layout
$ sudo raspi-config
$ sudo apt-get update
$ sudo apt-get upgrade


GPIO
====
old/new
#1 3V3         #2 5V
#3 0/2(SDA0/1) #4 5V
#5 1/3(SCL0/1) #6 Gnd
#7 4           #8 14(TX)
#9 Gnd         #10 15(RX)
#11 17         #12 18
#13 21/27      #14 Gnd
#15 22         #16 23
#17 3V3        #18 24
#19 10(MOSI)   #20 Gnd
#21 9(MISO)    #22 25
#23 11(SCLK)   #24 8
#25 Gnd        #26 7

$ sudo python
> import RPi.GPIO as GPIO
> GPIO.RPI_INFO
> GPIO.RPI_INFO['P1_REVISION']
> GPIO.VERSION
> GPIO.setwarnings(False)
> GPIO.setmode(GPIO.BCM)
> GPIO.setup(23, GPIO.IN)
> GPIO.setup(23, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)
> GPIO.setup(24, GPIO.IN, pull_up_down=GPIO.PUD_UP)
> if GPIO.input(23) == 1:
>   pass
> GPIO.wait_for_edge(23, GPIO.RISING)
> GPIO.wait_for_edge(23, GPIO.FALLING)
> GPIO.setup(23, GPIO.OUT, initial=GPIO.HIGH)
> GPIO.output(23, GPIO.LOW)
> GPIO.cleanup()


Kamera
======
Hidupkan kameranya
$ sudo raspi-config

Tiga ribu milidetik menuju cheese
$ raspistill -t 3000 -o test.jpg
JPEG quality 10% ukuran VGA
$ raspistill -w 640 -h 480 -n -t 100 -q 10 -e jpg -th none -o vga_100ms_jpg10.jpg

Biar punya /dev/video0
$ sudo modprobe bcm2835-v4l2
$ sudo nano /etc/modules
tambahkan baris bcm2835-v4l2


RPI-Clone
=========
$ wget https://github.com/billw2/rpi-clone/archive/master.zip
$ unzip master.zip
$ cd rpi-clone
$ sudo cp rpi-clone rpi-clone-setup /usr/local/sbin
$ sudo rpi-clone sdb
$ sudo rpi-clone sdb -s new_hostname


Save SD Card Life
=================
$ sudo nano /etc/fstab
Tambahkan ini
none	/var/log	tmpfs	size=1M,noatime				0	0
tmpfs   /tmp    	tmpfs   defaults,noatime,mode=1777,size=30m	0	0
$ sudo dphys-swapfile swapoff
$ sudo dphys-swapfile uninstall
$ sudo update-rc.d dphys-swapfile remove


Python Get CPU Temperature
==========================
def getCPUtemperature():
    res = os.popen("vcgencmd measure_temp").readline()
    temp =(res.replace("temp=","").replace("'C\n",""))
    return int(float(temp))

Python Get Raspi Serial Number
==============================
http://www.raspberrypi-spy.co.uk/2012/09/getting-your-raspberry-pi-serial-number-using-python/
def getserial():
  # Extract serial from cpuinfo file
  cpuserial = "0000000000000000"
  try:
    f = open('/proc/cpuinfo','r')
    for line in f:
      if line[0:6]=='Serial':
        cpuserial = line[10:26]
    f.close()
  except:
    cpuserial = "ERROR000000000"
  return cpuserial


HCSR04
======
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM)

GPIO_TRIGGER = 18
GPIO_ECHO    = 24
GPIO.setup(GPIO_TRIGGER, GPIO.OUT)
GPIO.setup(GPIO_ECHO, GPIO.IN)

def distance(): # centimeter
    GPIO.output(GPIO_TRIGGER, True)
    time.sleep(0.00001)
    GPIO.output(GPIO_TRIGGER, False)

    while GPIO.input(GPIO_ECHO) == 0:
        pass
    StartTime = time.time()
    while GPIO.input(GPIO_ECHO) == 1:
        pass
    StopTime = time.time()
    distance = 34300 * (StopTime - StartTime) / 2

    return distance


WS2812B
=======
$ sudo apt-get install python-pip
$ sudo pip install rpi_ws281x
$ nano ws2812b.py
import time
from rpi_ws281x import x
LED_COUNT = 12
#GPIO18 (Pin#12)
strip = Adafruit_NeoPixel(LED_COUNT, 18, 800000, 10, False, 255, 0)
strip.begin()
for i in range(strip.numPixels()):
  strip.setPixelColor(i, Color(255,255,255))
strip.show()