[casper] Roach2 i2c read/write failures

Hi ALL!!! I have one ROACH-2 boards (ver.2) telling somethings about i2c read/write failures at boot time (log attached). I have checked all internal cables and wires and it seems to be all ok, all fans are rotating at nominal speed (they sound like other ROACHs). Does anybody have got the same

Re: [casper] Roach2 i2c read/write failures

Hi ALL!!! I have one ROACH-2 boards (ver.2) telling somethings about i2c read/write failures at boot time (log attached). I have checked all internal cables and wires and it seems to be all ok, all fans are rotating at nominal speed (they sound like other ROACHs). Does anybody have got the

Re: [casper] Roach2 i2c read/write failures

Thanks John, but I see this behaviour only on one board out of 4 with the same conditions, I guess should be deterministic, doesn't it? 2014-11-17 13:22 GMT+01:00 John Ford jf...@nrao.edu: Hi ALL!!! I have one ROACH-2 boards (ver.2) telling somethings about i2c read/write failures at boot

Re: [casper] Roach2 i2c read/write failures

Yes the same U-boot version and boot procedure. How can test it without looking at the terminal console? Thanks, Andrea 2014-11-17 13:40 GMT+01:00 John Ford jf...@nrao.edu: Thanks John, but I see this behaviour only on one board out of 4 with the same conditions, I guess should be

Re: [casper] Roach2 i2c read/write failures

Yes the same U-boot version and boot procedure. How can test it without looking at the terminal console? Does the message end up in dmesg? I can't remember. If so, you can log in via ssh or by plugging in the usb as suggested by Bob Stricklin and look there. This problem was very repeatable

Re: [casper] Roach2 i2c read/write failures

This problem is likely the FTDI not being configured to tristate the IIC pins on reset, hence they are likely driven. This may be weakly enough that IIC open drain might work, or possibly some are configured to tristate and other aren't, or the config is random - just a thought.