Wrong image values / strange rollover about pylepton HOT 6 CLOSED

Thanks Itay, this is very interesting and odd. I presume that this something that happens during continuous capture? If you power off the module and do a single frame capture, does it return data as expected?

There's a line counter in there which returns values from 0-59 (in the LS first 12 of 16 bits of a line), and there's also a CRC that is computed against that counter (second 16 bits), and I wonder if that's what we're seeing here.

If not keeping up with real time demands of the module (which we are just barely now in Python), we can pretty easily get out of sync with the driver and start getting crazy data. For example I've had issues re-allocating the capture buffer every time.

Another thing I noticed the other day is that the SPI Mode is set wrong (0, which was not set in the original C program), where according to the docs, it is supposed to be 3 (CPOL=1, CPHA=1), so we could be clocking out data with the wrong polarity on the wrong edge, arg! Strangely an fortuitously, this setting must be ignored by the driver. It might be worth changing that though.

Please let me know if you learn any more. When I've got a chance soon I'll do some investigation too.

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Got it!

You're right, it was the SPI mode.
I tried setting it at 3, but got garbage.
The magic number is mode 1, i.e. the trailing edge.

I'll do some thorough testing tomorrow, but right now it seems to have solved this sync problem.

Thanks so much!

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Are you on a Raspberry Pi or some other platform with spidev?

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I'm using RPi 2, running Raspbian 8 (Jessie).
What would you like me to check?

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Just checking. Please let me know if this continues working for you. Mode 2 is CPOL=1, CPHA=0, which isn't quite what the datasheet calls out. Considering that this was basically working with CPOL=0 before, I'm still a little confused by this.

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Hey Itay, I pushed a couple fixes to improve throughput and reliability (just to avoid potential issues there) and set SPI mode 3. This is working well for me and I have values in the correct range. Please let me know if you are still having problems.

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