Values greater than approx. 100 ms are unreliable for connectable unidirected advertisements, ex. 150 ms equals more likely to 800 ms, 1280 ms - 6500 ms (with high variations). Non-connectable unidirected advertisements' intervals are reliable. BTstack it is not the root of the problem. It is the same with or without it - just HCI commands written by cyw43 driver. To reproduce, just use some BTstack example, like hog_mouse_demo.c:
adv_int_min and adv_int_max are values of intervals in number of time slots (0,625 ms). Min value is 32 (0x20), max 16384 (0x4000). adv_type of 3 will switch it to non-connectable unidirected. It seems to be more likely firmware or CYW43439 ROM for Bluetooth.
Values greater than approx. 100 ms are unreliable for connectable unidirected advertisements, ex. 150 ms equals more likely to 800 ms, 1280 ms - 6500 ms (with high variations). Non-connectable unidirected advertisements' intervals are reliable. BTstack it is not the root of the problem. It is the same with or without it - just HCI commands written by cyw43 driver. To reproduce, just use some BTstack example, like
hog_mouse_demo.c:adv_int_minandadv_int_maxare values of intervals in number of time slots (0,625 ms). Min value is 32 (0x20), max 16384 (0x4000).adv_typeof 3 will switch it to non-connectable unidirected. It seems to be more likely firmware or CYW43439 ROM for Bluetooth.