David Swinnard replied to the topic 'Flat Panels Question' in the forum. 5 months ago

Regarding the two versions of the Alnitak command sequence protocol (Rev 3 of 2011 and Rev 44 of 2017).

I used the later one for my first cut of Arduino code (using command strings with capital "O" rather than with zeros). Initial testing back in September (Kstars 3.5.5) brought up some issues that Jasem fixed for 3.5.7. With 3.5.7 installed further testing results prompted me to monitor the USB packets exchanged between Ekos/Indi to the Arduino controller. I discovered these commands used the older version of the protocol, the one with zeros. Looking at the indi_flipflat driver source code (flip_flat.cpp) confirmed commands issued use the zeros structure (e.g. "if (!sendCommand(">P000", response))" which results in " >P000CR" being sent to the flat panel's Arduino controller.

I investigated all the Arduino programs listed in this thread but eventually settled on a modified (by me) version of the code found on the gluonfield.com site ( gluonfield.com/spacelike/content/astrophotography-flats-panel ). Basically I went back to using the zeros and the CR an LF command terminators.

As I mentioned I used a DIY LED based solution with a few 3D printed parts (courtesy of my son) to make a panel that slips over my OTAs dew shield like a lens cap. The Arduino with a MOSFET to switch the 12V required by the LED string mount on top of the panel assembly.

Although this flat panel solution has taken months of time and trial and error it did save me some money and provided an opportunity to add to my (minimal) programming and fabrication skills. Being essentially confined to home and literally having no opportunities to take astrophotos since my last session in late October this project along with a dew heater controller has kept me somewhat sane.

Dave

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