Hi, Tom, I suggest using an oscilloscope to probe the SPI signals on the ZDOK0 ADC card while writing to it. Based on this schematic:
https://casper.berkeley.edu/wiki/images/d/d2/Schematic_ADC_A2_5G_DMUX11.pdf ...it looks like you can probe them at CN5 or CN2 since you know the cards themselves are good (since they both work OK in ZDOK1). You might find that one of the SPI signals is not present (e.g. maybe because of a bad solder joint on the ZDOK connector). Or you might find that none of the SPI signals are present (e.g. maybe because of a software bug). Hope this helps, Dave On Sep 12, 2014, at 6:28 AM, Geelen, T.F.G. wrote: > Hi, > > Here is some clarification. > > To be precise it seems impossible to calibrate the ADC board connected to > ZDOK0. (the other one than Ricardo mentioned). We have a script which tries > to calibrate the 4 cores inside the ADC board considering phase,amplitude and > offsets. > > So what we do is essentially the following: > - We take a snapshot of the ADC output when it is still uncalibrated using a > 10 MHz sine wave on the input. > - We calculate the gain, offset and phase of the received signal to balance > the cores > - We write the values back to the OGP registers in the ADC. > - We take a second snapshot to check if it worked. > > For the ADC connected to ZDOK1 this all seems to go fine and the resulting > wave is a perfect sine wave. When we try to write however to the ADC in ZDOK0 > it does not seem to respond. > The resulting sine wave is still exactly the same and it seems the OGP > registers do not get written. > > Furthermore if we switch the actual ADC boards from ZDOK it seems that the > problem stays in ZDOK0. > > Parameters we use: > - demux 1:1 mode > - single channel mode > - ADC board: https://casper.berkeley.edu/wiki/ADC1x5000-8 > > Kind regards, > > Tom > ________________________________________ > Van: casper-boun...@lists.berkeley.edu [casper-boun...@lists.berkeley.edu] > namens Geelen, T.F.G. [t.f.g.gee...@student.tue.nl] > Verzonden: dinsdag 9 september 2014 17:19 > Aan: CASPER Mailing List > Onderwerp: [casper] Problem calibrating ADC for ROACH2 > > Hi everyone, > > We have trouble here in the laboratory trying to calibrate the ADC's for our > ROACH2. It is still the same problem we had been having a month ago. > > We started working with the paper: 'CHARACTERIZING THE PERFORMANCE OF A > HIGH-SPEED ADC FOR THE SMA DIGITAL BACKEND' and the code provided. > Modifying the code as necessary we have been succesfully able to calibrate > the ADC connected to ZDOK1. The other ADC however does not seem to get > calibrated at all. > We checked if it was a hardware issue by switching the ADC's from ZDOK port > and the problem switched too. Somehow the ADC board in ZDOK0 is not > calibrated correctly. > > Since it works on one perfectly and not on the other the obvious place to > look was in our code but so far we have not been able to find a mistake in > the code. At the moment we are a bit stuck as to ideas what could be causing > this problem. > > Any suggestions from the community? > > Regards, > > Tom
