conversion_gain

Conversion gain note

All FSM:GO sensors implemented on NXP support high and low conversion gain functionality, with low conversion gain being the default one.

To change from low to high conversion gain you can use the v4l2-ctl command via

 v4l2-ctl -d /dev/v4l-subdev1 -c conversion_gain=1

This will change the mode to high conversion one, so its basic functionality can be tested.

The limitation is that if Auto Exposure algoritm (AEC) is used the algorithm will still use minimal gain for low conversion mode. In order to set minimum high conversion for isp one must rebuild the source with setting

.min_again = gain_reg2times[IMX838_GAIN_REG_LEN]

This will set a minimum gain to minimal high conversion gain for isp auto exposure algorithm.