Optical flow gives no values in Kakute F7 Mini. Same thing works on Kakute F7 on Copter 3.6.12 though. Copter 4.0.0 has the same issue with kakute F7 too. Also, this is after the fix suggested in #10105.
I also tried deleting all the code in AP_OpticalFlow.cpp to force it to use PX4Flow such that the only code remaining in void OpticalFlow::init(uint32_t log_bit) is backend = AP_OpticalFlow_PX4Flow::detect(*this); and backend->init();. No luck.
OK, thanks for the report. I’ve added it to the Copter-4.0 issues list so it won’t be forgotten. There seem to be at least 2 other reports of this issue as well.
It’s possible that this small fix to check all I2C ports may resolve the issue on the KakuteF7 mini. It’s also possible that there is a boot timing issue. It may help to increase the BRD_BOOT_DELAY parameter to 6.