This Open Research Institute (ORI) projects report details significant progress and challenges across multiple FPGA and radio system initiatives. Aaron reported successfully porting a DVBS2 encoder to the OpenCPI framework, overcoming VHDL 2008 compatibility issues to generate a valid bitstream for a ZCU104 board. Paul announced a major breakthrough in resolving critical timing and data gap issues in the software feeding a PlutoSDR, achieving a stable data stream to the FPGA modem, which was verified using a high-speed spectrum analyzer. Debugging efforts on an MSK modem revealed a complex issue where it performs perfectly with internal test data but fails with external data streams, leading to an in-depth investigation of its dual Costas loops. The radio astronomy team celebrated a major success with the detection of the faint and fast-spinning Crab Pulsar, validating the telescope's sensitivity, while also troubleshooting data collection software for a galaxy drift scan experiment. The meeting also covered future plans for automated network testing, new hardware acquisitions, and upcoming conference presentations.
ORI Project Updates and Roundtable Highlights
00:00:26 DVBS2 Encoder Ported to OpenCPI: Aaron successfully ported a DVBS2 encoder to the OpenCPI framework. He overcame VHDL 2008 compatibility issues by creating a Vivado design checkpoint and importing it as a primitive, leading to a successful bitstream generation for a Xilinx ZCU104 board.
02:10 Next Steps for Encoder Integration: The next phase involves writing the logic to initialize the encoder's IP core through its AXI4-Lite interface, which will bring the modulator online for use.
06:01 PlutoSDR Data Flow Issues Resolved: Paul has fixed critical timing and latency problems in the software that feeds data from a network interface to the PlutoSDR. The fix eliminates data gaps that were disrupting the FPGA modem, which requires a perfectly steady data stream.
08:25 Stable Data Transmission Achieved and Verified: The new software plan ensures a data frame is sent reliably every 40 milliseconds with minimal jitter. This stability was confirmed using the "Maia" project as a high-speed spectrum analyzer, showing the transmission gaps have been eliminated.
11:33 Advanced Hardware for Debugging: To assist with complex USB and network data flow issues, the team is acquiring a USB tracing device and has obtained advanced PlutoSDR clones like the Libre SDR, which feature Ethernet support and larger FPGAs.
19:53 MSK Modem Simulation Fails with External Data: A simulation testbench for the MSK modem shows it works perfectly with an internal pseudo-random (PRBS) data source but fails to produce coherent output when fed with an external data stream via its AXI interface.
24:03 Investigating Complex Costas Loop Behavior: The team is investigating why the modem's received data is garbled with external inputs. An initial theory of "error starvation" in the dual Costas loops was partially addressed, but the underlying issue persists, suggesting a more complex problem.
31:55 Radio Astronomy Data Pipeline Troubleshooting: Rick is working to diagnose performance issues in the galaxy drift scan data collection pipeline at the Haswell (DSES) site by comparing results from two different GNU Radio-based analysis packages to isolate the problem.
46:21 Major Milestone: Crab Pulsar Detected: The team successfully detected the Crab Pulsar, the weakest (550 mJy) and fastest-spinning (33ms period) pulsar the project has ever captured. This achievement serves as a key validation of the radio telescope's high sensitivity and system performance.
01:03:09 Automated Network Testing Environment: Paul plans to create a repeatable, automated test environment for the data flow software using TCP Replay, an open-source tool that can play back captured network traffic to simulate real-world conditions.