Do you know what the register write commands should be to put the OV2640 into standby ?
The OV2640 has a different register structure to the OV3660, it looks like you need to write register 0x09 in bank 1 with a value of 0x10.
I tried this;
sensor->set_reg(sensor, 0xFF, 0xFF, 0x01); //camera to reg bank 1
sensor->set_reg(sensor, 0x09, 0xFF, 0x10); //camera to standby
but get an error;
E (29729) sccb: SCCB_Write Failed addr:0x30, reg:0xff, data:0x01, ret:263
E (31730) sccb: SCCB_Write Failed addr:0x30, reg:0x09, data:0x00, ret:263