Tag: interactive media

GPS on Raspberry Pi

Successfully installed this GPS board on the R-Pi.

By Kevin Townsend at adafruit.com

http://learn.adafruit.com/adafruit-ultimate-gps-on-the-raspberry-pi/introduction

The drivers for the console cable were already in the Raspian distribution on the R-Pi.

I installed the gpsd (daemon) software as directed in the above tutorial.

Documentation for gpsd is here:

http://gpsd.berlios.de/client-howto.html

Sample C code is: gpxlogger.c and cgps.c – which can be found in tkzic/rpi/gpsd 3.7/

(todo – write sample code and add to telemetry tracker)

Google+ hangouts studio mode

(update)  The studio mode option in Hangouts only appears on the settings menu after you have checked ‘hangouts on air’ and then actually started the Hangout. Only then can you goto settings (gear icon) and select studio mode.

Uses the Celt codec: http://support.google.com/plus/bin/answer.py?hl=en&answer=2664557

GOOGLE+ HANGOUTS ON AIR: AUDIO SETUP GUIDE FOR STUDIO MODE

By David Santy Music

http://davidsantymusic.com/hangouts-on-air-studio-mode-audio-guide/

Raspberry-Pi RTTY beacon and streaming webcam – success

Update: 5/2014

Retrying this experiment using the Arduino circuit described here: http://reactivemusic.net/?p=12161

notes
  • 300 baud
  • 300 Hz carrier shift
  • 8 bits
  • 2 stop
  • no parity
  • filter at 300 Hz
  • Normal mode (not reverse)
  • AFC on
There are 2 programs:
  • serial.c – sends a beacon then transmits a 640×480 picture
  • serial-beacon.c – just sends a beacon
In order to view the picture as it comes in in dl-fldigi, you need to open up the SSDV RX window in the View menu.
The frequency is not very stable and occasionally you need to just restart dl-fldigi because the screen fills with trash characters.
Also, in Max, you need to tune on the right half of the picture.
Will be setting up a test with smaller photos

 

Success: Got an accurate beacon at 300 baud today and send a jpeg picture file , taken by a webcam connected to the R-Pi using fswebcam and SSDV.

http://www.slblabs.com/2012/09/26/rpi-webcam-stream/

Used the same circuit as the previous post about the Arduino RTTY beacon.

The difference is that we’re using a C program to write the text directly to the serial port which modulates the NTX2 transmit frequency.

Transmission can be stopped and started using the sleep() function but the timing is not exact.

Local code

tkzic/rpi/serial/serial1 –

  • using command line SSDV converter in tkzic/rpi/ssdv-master.
  • Using dl-fldigi to decode RTTY and SSDV pictures.
  • Using logictech c210 webcam – see link above for how to take a picture and save to file use fswebcam.

 

 

[Todo:]

  • Set up a shell script to take pictures and transmit regular intervals.
  • upload code and photos
  • Build some antennas
  • Field test
  • Buy a balloon

 

 

how to open, read, and write from a serial port in C (linux)

With applications for Raspberry Pi

notes

by hobbytronics.com

http://www.hobbytronics.co.uk/raspberry-pi-serial-port

C – programming example:

http://stackoverflow.com/questions/6947413/how-to-open-read-and-write-from-serial-port-in-c

An R-Pi thread about connecting Arduino to R-Pi. R-Pi does TTL (3.3 v level and Arduino is rs-232 5v) so you need a level converter for them to communicate.

http://www.raspberrypi.org/phpBB3/viewtopic.php?f=31&t=23873

Another similar example, connecting Arduino and R-pi via USB

http://www.raspberrypi.org/phpBB3/viewtopic.php?f=32&t=28801

The WiringPi library for serial io:

https://projects.drogon.net/raspberry-pi/wiringpi/serial-library/