bv3ue radio blog

Raspberry Pi and RTL-SDR

Raspberry Pi and RTL-SDR
1. Installation package
Web: http://www.hamradioscience.com/raspberry-pi-as-remote-server-for-rtl2832u-sdr/

For RTL-SDR(Elonics E4000 or Rafael Micro RT-820 silicon tuner + Realtek RTL2832U IF demodulator), do the following command
=====
sudo apt-get install git
sudo apt-get install cmake
sudo apt-get install libusb-1.0-0.dev
sudo apt-get install build-essential
git clone git://git.osmocom.org/rtl-sdr.git
cd rtl-sdr/
mkdir build
cd build
cmake ../
make
sudo make install
sudo ldconfig
=====

2. Check and execution
a. insert RTL-SDR dongle into RPi's USB port(SSH connection will be interrupt then reconnect again)
b. run "lsusb" to see RTL2838 DVB-T is shown and supported
c. run "sudo rtl_tcp -a 192.168.1.11", 192.168.1.11 is IP of RPi, default port is 1234
d. open Windows SDRSharp to select RTL-SDR/TCP
e. Configure as Hostname: 192.168.1.11, Port: 1234
f. Play to work

RPi and FunCubeDongle Pro

Raspberry Pi Basic Usage

Raspberry Pi Basic Usage

1. Raspberry Pi(RPi) connect with power and network only
2. use Xshell4(SSH protocol) to connect the RPi in terminal mode
3. start the VNC server in RPi and connect TightVNC in Window mode
4. transfer the data between RPi and computer with Winscp

Step 1 power and network connection

Step 2: Xshell4 connection

(192.168.1.11 is RPi's IP assigned by my DHCP serveri, 5901 is the VNC connection default port)

Step 3: tightVNC connection setup and connected screen picture

Step 4: Winscp connection

Notes:
a. The router will play as DHCP server and RPi will request an IP address from the DHCP server
b. Use Ws_ping ProPack to scan the network for finding the RPi assigned IP or open the DHCP server UI to assign a fixed IP to RPi
c. RPi will start the SSH server automatically(see /etc/rc2.d/S02ssh). To use the SSH client(Xshell4 or SecureCRT) to connect RPi
d. For X Window access, install tightVNC server as "sudo apt-get install tightvncserver", then start vncserver as "vncserver"
e. tightVNC viewer to connect vncserver(vncserver password need provided)
f. Winscp to work as ftp clinet to upload/download to RPi

Good sides for this connection

a. RPi need connect power and network only,no USB keyboard and mouse, neither to concern about HDMI or Video setting to get high resolution output. SSH connection will use less system resource
b. The desktop PC can connect Internet and Rpi same time. To Google the question and cut-and-paste result to SSH terminal for trying

Raspberry Pi usage log

Raspberry Pi usage log

Booting setup
=====
1. expand_rootfs Expand root partition to fill SD card(*** necessary)
to use the SD card fully and improve the execution performance

02. configure_keyboard Set keyboard layout(*** necessary, for direct keyboard connection), *option(for SSH connection, the SSH client will handle the keymap)
RPi default with UK keyboard and some character is not match the US keyboard layout. To select the US keymap to solve it

03.change_pass Change password for 'pi' user(*option)
RPI default account and password is "pi" and "raspberry"

04.boot_behaviour Start desktop on boot?(*option)
To save the computing resource, run the terminal mode(SSH login) as default. (Should we boot straight to desktop? No), "startx" restart the X Window

ps. run "sudo raspi_config" to start the menu again later time

Navspark: Arduino compatible GPS module

Navspark: Arduino compatible GPS module

Taiwan GPS chip provider Skytraq is working on an Arduino-like board with additional GNSS, GLONASS, Beidoo position capability.
http://www.indiegogo.com/projects/navspark-arduino-compatible-with-gps-gnss-receiver

If you buy and use the Arduino board(UNO, Nano...), you will feel the GPS function is provided as free!!

Want to get centimeter position accuracy ? there is a carrier-phase raw measurement kit provided. You can do a post-processing with RTKLIB to get that position accuracy.

Board picture

Satellite Constellation

Funcube Dongle Plus Pro information

1. Funcube Dongle Pro+ front-end chip is Mirics's MSi001(or Msi002). Its block diagram show 6-ways LNA to cover different impedance and frequency range. RF signal is down-converted to LIF or ZIF and seperated to I/Q signal. The I/Q signal is filtered and amplified for ADC.

2. Mirics provide IF IC - MSi2500 to get ADC resolution to 10bits. It is better than RTL2832 in 8 bits. The highest sample rate reach 12Msps. Due to the USB 2.0 HS(480Mbps), the selected sampling rate is about 2 to 3Msps.

3. FCDP use the audio codec with maximum sampling rate to 192Ksps. For Funcube satellite, it is adequate. There is another SDR USB dongle called SDRplay using FE filter+MSi001+MSi2500 to get wider signal bandwidth and better noise immunity.

Msi001 and Msi2500 chipset Block Diagram

Funcube Dongle Plus Block Diagram

BLDC evaluation platform PT2431

Motor IC Evaluation and Demo Platform

Design Concept

The motor control IC PT2431 feature with

PWM input signal for speed control

FG output for speed indication in open-drain configuration

RD output for lock indication in open-drain configuration

We want to build a user interface(UI) in computer or mobile phone to control motor speed with different PWM ratio and get the reading of FG and RD for speed and lock information

In the same time, the evaluation board is also equipped with PWM control and information display in case there is no computer and mobile phone provided.

Free developing toolchain: Arduino, Python and QT

Design project idea - FM Radio and Alarm

Design project idea - FM Radio and Alarm

Feature
1. FM Radio
2. Different device can exchange information
3. Alarm with time accuracy below 1ms daily
4. Alarm to talk hour and specified voice

One time charge to survive 1 month
Time sync with GPS or BLE
Voice sync with BLE thru handset, handset can deliver voice thru network as answer machine
Each device can sync time, radio station and voice information thru RDS or BLE

Hardware
BLE: nRF51822
GPS: SkyTraq Navspark