drv/bluetooth_stm32_cc2640: fix technic hub broadcast

Broadcasting was not working on Technic hub when it was not connected
to another device (e.g. computer or remote control). This adds a check
for connected state and applies the same hack of using ADV_IND like
City hub if needed.

Fixes: pybricks/support#1086

CHANGELOG.md

@@ -13,8 +13,10 @@
 ### Fixed
 - Fixed BLE broadcast not working on City hub.
 - Fixed crash on BTStack hubs when program stopped during call to `ble.broadcast()`.
+- Fixed BLE broadcast not working on Technic hub when not connected ([support#1086]).
 
 [support#402]: https://github.com/pybricks/support/issues/402
+[support#1086]: https://github.com/pybricks/support/issues/402
 
 ## [3.3.0b5] - 2023-05-16
 

lib/pbio/drv/bluetooth/bluetooth_stm32_cc2640.c

@@ -864,7 +864,10 @@ static PT_THREAD(broadcast_task(struct pt *pt, pbio_task_t *task)) {
             // send something over the air.
             ADV_IND,
             #else
-            ADV_NONCONN_IND,
+            // Technic hub will send non-connectable advertisements only if
+            // it is connected to something else, otherwise we need the same
+            // hack as the City hub.
+            (conn_handle == NO_CONNECTION && remote_handle == NO_CONNECTION) ? ADV_IND : ADV_NONCONN_IND,
             #endif
             GAP_INITIATOR_ADDR_TYPE_PRIVATE_NON_RESOLVE, NULL,
             GAP_CHANNEL_MAP_ALL, GAP_FILTER_POLICY_SCAN_ANY_CONNECT_ANY);