Hi Daniel, On Tuesday 31 May 2011 11:45:13 Daniel Lundborg wrote: > > On Thursday 26 May 2011 15:06:17 Daniel Lundborg wrote: > > > > On Thursday 26 May 2011 10:57:39 Daniel Lundborg wrote: > > > > > Hello, > > > > > > > > > > I am developing a camera sensor driver for the Aptina MT9V034. I > > > > > am only using it in snapshot mode and I can successfully trigger > > > > > the sensor and receive pictures using the latest omap3isp driver > > > > > from git://linuxtv.org/pinchartl/media.git branch > > > > > omap3isp-next-sensors with kernel 2.6.38. [snip] > > > > > My trouble is that I am always receiving whiter pictures when I > > > > > wait a moment before triggering the sensor to take a picture. If I > > > > > take several pictures in a row with for instance 20 ms between > > > > > them, they all look ok. But if I wait for 100 ms the picture will > > > > > get much whiter. > > > > > > > > > > I have turned off auto exposure and auto gain in the sensor and > > > > > the LED_OUT signal always have the same length (in this case 8 > > > > > msec). > > > > > > > > I assume you've measured it with a scope ? > > > > > > > > Try disabling black level calibration and row noise correction as > > > > well. > > > > > > > > Please also double-check that AEC and AGC are disabled. I've had a > > > > similar issue with an MT9V032 sensor, where a bug in the driver > > > > enabled AEC/AGC instead of disabling them. > > > > > > The register on 0xaf (MT9V034_AGC_AEC_ENABLE) is set to 0 and is 0 > > > when I read from it. > > > bit 0 - AEC enable context A, bit 1 - AGC enable context A, bit 8 - > > > AEC enable context B, bit 9 - AGC enable context B > > > > > > The register on 0x47 (MT9V034_BL_CALIB_CTRL) is set to 0 and is 0 > > > when I read from it. > > > bit 0 - (1 = override with programmed values, 0 = normal operation), > > > bit 7:5 - Frames to average over > > > > If I'm not mistaken "normal operation" means that automatic black > > level calibration is enabled. Try to set bit 0 to 1 to override the > > automatic algorithm (and program a zero value in register 0x48). > > This did not work unfortunately.. :( I have solved this by always taking > 2 pictures and ignoring the first of them... :-/ Any chance you will submit the driver for inclusion in the kernel ? -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
