Red Wire Technologies

To work with the RWT Oxygen SDR, a computer running Linux or similar operating system is required. At the current time Microsoft Windows is not supported. Also being familiar with Linux, ssh, and the Linux command line will improve your use and understanding of the RWT Oxygen SDR.

A Hard case containing:

1. RWT Oxygen SDR Development kit
2. 12-V Power power supply
3. GPIO breakout cable
4. USB3-Type A to USB-C cable
5. USB-C to USB-C cable
6. A microSDXC card which is pre-loaded with the latest release of software for the RWT Oxygen SDR
7. Console/Debug port header extension connector (Samtec ESQ-106-44-L-D)

Remove the microSDXC card from the case and insert it in the sd card slot, which is under the rubber cover on the side of the case closest to the the labeled GPS SMA connector. Connect a USB-C cable to the port labeled “DEVICE” and the other end to your host computer. Connect the barrel end of the power supply to the power connector on the Oxygen SDR, which is located under a rubber cover between the power button and the LED power indicator. Plug the power adapter in. The LED indicator will appear as an orange light. Press and hold the power button for 5 seconds to power up the Oxygen SDR. The LED indicator light will change to green when the system is turned on and operating. Your host computer should display a new Ethernet interface in 1-2 minutes. To access the command line of the Oxygen SDR type

  ssh -X root@192.168.10.1

in a terminal window on the host computer. Answer “yes” to the question concerning the security key being provided.

The Linux image which is provided with the RWT Oxygen contains GNU Radio 3.10 plus multiple OOT modules to maximize the use of the software defined radio. To start GNU Radio Companion type:

  gnuradio-companion

on the command line in the terminal window which was used to log into the Oxygen SDR. The first time this command is run it may take a few minutes for GNU Radio Companion to start. The GNU Radio blocks for controlling the Oxygen SDR are in the block section “RWT”. For first time testing use the blocks “RWT Sink” and “RWT Source” to control the Oxygen SDR. In order to receive or transmit, an antenna will need to be connected to the correct ports of the radio covering the desired band of operation. For users who are not experienced with GNU Radio, RWT recommends completing the GNU Radio tutorials at https://wiki.gnuradio.org/index.php/Tutorials.

If you desire to directly control the enabled state of the RX and TX on the chip, this can be done through the command line.

First, you must run the following command after having loaded the FPGA. The FPGA may be loaded either via the fpgaloader command (as detailed here).

  echo pinctrl_fdd_indep > /sys/bus/iio/devices/iio:device1/ensm_mode    

After running this command you can control the RX and TX directly via GPIO pins. To turn on/off the RX, you will set GPIO pin 125 to 1/0 respectively.

  gpioset 0 125=1

Similarly, to turn on/off the TX, you will set GPIO pin 126 to 1/0 respectively.

  gpioset 0 126=1 

RWT has provided examples of GNU Radio Companion files to demonstrate some capabilities of the RWT Oxygen hardware. More details are on the examples page.

The RWT Oxygen has more advanced capabilities, including the ability to reload the FPGA while running, the ability to custom build a Linux OS, and the ability to operate in a network attached mode using IIO controls. The radio can be used with GR-IIO. More details are on the advanced operations page