wraggster
January 25th, 2013, 23:28
http://hackadaycom.files.wordpress.com/2013/01/rpi-beacon-transmitter.jpg?w=580&h=406
[m0xpd] got his hands on an inexpensive AD9850 DDS Module from eBay but needed a way to control it. He took inspiration from the projects that used a PIC microcontroller, but decided to add his own twist by using a Raspberry Pi to build a multi-mode beacon transmitter (http://m0xpd.blogspot.co.uk/2013/01/multi-mode-beacon-on-rpi.html).
At the center of this breadboarded circuit lies the green AD9850 module. To its left is a level converter he built to get the 3.3V levels from the RPi board to work with the rest of the 5V hardware. The signal then feeds into a QRP amplifier and a low pass filter.
He didn’t start from square one when it came time to write the code for the RPi. Instead he grabbed an Arduino sketch for the very same DDS and ported it over to Python. The first test signal was his call sign sent in Morse code at QRSS speeds (http://en.wikipedia.org/wiki/QRP_operation#QRSS). But he also managed to get Hellschreiber (http://hackaday.com/2012/01/12/hellduino-hellschreiber-radio-transmissions-from-an-arduino-board/) messages working, making it a multiple-mode device.
http://hackaday.com/2013/01/25/raspberry-pi-used-as-a-beacon-transmitter/
[m0xpd] got his hands on an inexpensive AD9850 DDS Module from eBay but needed a way to control it. He took inspiration from the projects that used a PIC microcontroller, but decided to add his own twist by using a Raspberry Pi to build a multi-mode beacon transmitter (http://m0xpd.blogspot.co.uk/2013/01/multi-mode-beacon-on-rpi.html).
At the center of this breadboarded circuit lies the green AD9850 module. To its left is a level converter he built to get the 3.3V levels from the RPi board to work with the rest of the 5V hardware. The signal then feeds into a QRP amplifier and a low pass filter.
He didn’t start from square one when it came time to write the code for the RPi. Instead he grabbed an Arduino sketch for the very same DDS and ported it over to Python. The first test signal was his call sign sent in Morse code at QRSS speeds (http://en.wikipedia.org/wiki/QRP_operation#QRSS). But he also managed to get Hellschreiber (http://hackaday.com/2012/01/12/hellduino-hellschreiber-radio-transmissions-from-an-arduino-board/) messages working, making it a multiple-mode device.
http://hackaday.com/2013/01/25/raspberry-pi-used-as-a-beacon-transmitter/