Frigg's Day

See Wikipedia.

Today getting 175 Hz consistent pulse rate, after turning off INFO messages.  If I also turn off warnings, we avoid crashes, and get LOST_PULSES messages that tell us how many pulses were dropped.

Based on the present line length, my calculation is that a max of about 180 Hz is theoretically achievable based on the 115,200 baud rate, 10 bit-clocks per byte, 64 bytes per line.  In practice it looks like we can only get about 175 Hz sustainably though.  This is not too surprising, since there will inevitably be some amount of dead time in the serial link due to flow control.


Ray is talking about writing a paper.  I need to read the Stanev book, also "Astroparticle Physics" by Grupen, which he says I can get from the library.

On tap for next week (Ray's priorities):

1. Replicate the input capture datapath 3 times (not 4 yet) for the 3 paddles;
2. Also generalize the firmware to handle the multiple input sources;
3. Work on coincidence detection algorithm
4. Analysis for shower direction triangulation

Also, my own to-dos:

• It would be nice to have an occasional "heartbeat" from the FEDM, which will confirm that the main loop of the firmware is still running and hasn't crashed (to distinguish this from a case where the PMT is powered down or malfunctioning).  Perhaps a good way to do this would be to just poll the newlib clock() function in the main loop.  I need to write a new module heart.{c,h} to do this.  Heartbeats should carry a sequence number.
  
• Figure out why firmware isn't running automatically when .sof file is loaded.  Somehow it's not getting compiled into the design (I just did a recompile today, still no dice).  

BTW, I confirmed we're still working at 2 ns time resolution, although the timing analyzer reports fmax=480MHz.