Electromagnetic Radiation Test Devices

Electromagnetic Radiation Detectors:

  • DT-1130 (very cheap) (max 2 GHz)
  • Acoustimeter (200MHz – 8 GHz)

SSH Security on Raspberry Pi

Debian tips for SSH

Login attempts file: /var/log/auth.log

cat /var/log/auth.log | grep 'sshd.*Invalid'

Change SSH settings: sudo nano /etc/ssh/sshd_config

Change port from 22 to something else.

Install fail2ban: sudo apt-get install fail2ban

SSH Tunnel with Putty

Browse using remote server:

Use Putty like a VPN.


Source Port: 12345

Destination: Dynamic


Connect to your SSH Server. Dont’t close Putty.

Open browser proxy setttings.

Socks: Port: 12345


Access remote port:


Source Port: 12345

Destination: Server_Ip:Server_Port Local


Connect to your SSH Server. Dont’t close Putty.

Raspberry Pi Torrent

sudo apt-get install transmission-daemon
sudo nano /etc/transmission-daemon/settings.json
sudo service transmission-daemon reload

Change download directory to external drive:
sudo service transmission-daemon stop
sudo nano /etc/transmission-daemon/settings.json
Change download-dir from "/var/lib/transmission-daemon/downloads" to "/media/YourDriveName"
sudo nano /etc/init.d/transmission-daemon
Change USER to root or pi (It solves permission denied error)
sudo service transmission-daemon start

Solve external drive mount problem after rasperry pi restart:
sudo pico /etc/fstab
/dev/sda1   /media/YourDriveName   ntfs-3g   defaults   0   0
If drive is FAT, use vfat instead of ntfs-3g
sudo apt-get install ntfs-3g
sudo mkdir /media/YourDriveName
sudo mount -t ntfs-3g /dev/sda1 /media/YourDriveName

SoC (System On Chip)

A typical SoC consists of:

  • a microcontroller, microprocessor or digital signal processor (DSP) core – multiprocessor SoCs (MPSoC) having more than one processor core
  • memory blocks including a selection of ROM, RAM, EEPROM and flash memory
  • timing sources including oscillators and phase-locked loops
  • peripherals including counter-timers, real-time timers and power-on reset generators
  • external interfaces, including industry standards such as USB, FireWire, Ethernet, USART, SPI
  • analog interfaces including ADCs and DACs
  • voltage regulators and power management circuits