Tethered shoot in AV mode (Canon 400D)
I used "tethered shoot" in "darktable 0.9.1+101 g5bd9b16" together with my Canon 400D (frmwre 1.1.1) to create my very first time lapse and it worked perfectly as long as the light conditions didn't change too much. I shot 240 pictures at 30sec intervals, totaling 2 hours, and it went smooth.
When I tried to do the same later in the evening, with light changing fast, I added properties "aperture" and "autoexposuremode" to the "properties" tab under "camera settings", I set the aperture to 3.5 (max for my cheap lens) and the "autoexposuremode" to "AV", hoping that this would automatically modify the shutter speed as needed. It didn't. It took all the pictures at the established intervals, but the shutter speed didn't change, resulting in very dark pictures.