SPC900 Exposure idea Help

[JKB]

OK not sure if I'm heading the right way but had an idea.

I have a LX modded SPC which I have started to use as a guide cam.

Does anyone know if rather than having a parallel lead to control exposure it could be done with a 555 Timer chip?

What I'm thinking is making a small curcuit with a 555 that would send pulses to the LX wire to make, say 5 sec exposure times. This would save having to control via the PC and would be stand alone.

Any idea if this will work or is that not the way the LX lead works?

Thanks for your help

[samtheeagle]

I've been experimenting with a similar notion, but using an Arduino board to control the LX signal. It basically works, but what you have to realise is that the software needs to know which frame is the LX one. The camera apparently keeps returning frames during an LX exposure, they just don't have any data in them. So the software needs to know when to look for the LX frame. To get it to work I think it would require it's own ASCOM driver to handle the stream of frames from the webcam so that you could pick out the ones we're interested in.

It's a wee project I've got on the back burner atm, but I'll get to it eventually...

[JKB]

Thanks for the info Sam. Will do some experimenting and see what I can do.

Cheers

[malc-c]

If you have the serial modded version and the ability to monitor the RTS and DTR lines, you'll see that the RTS line will turn on and off at various times through the exposures, so I guess it's not a simple case of tieing a pin high or low for a fixed time so as to make the camera perminatly in LX mode

[theodore]

Hi,

any progress on this? I'd really like to do it because I can't use ports on my netbook.

Is there a way to sync the 555 'on' signal with the one telling the cam to take a frame? Or just split it?

Thanks,

Theo