Give BLE scan more options.

Most users shouldn't touch them, but for power users it's nice to have
them available.

lib/ble/ble.toit

@@ -1084,7 +1084,7 @@ ble-create-central-manager_ adapter-resource:
 ble-create-peripheral-manager_ adapter-resource bonding secure-connections:
   #primitive.ble.create-peripheral-manager
 
-ble-scan-start_ central-manager passive duration-us:
+ble-scan-start_ central-manager passive/bool duration-us/int interval/int window/int limited/bool:
   #primitive.ble.scan-start
 
 ble-scan-next_ central-manager:

lib/ble/remote.toit

@@ -58,11 +58,33 @@ class Central extends Resource_:
   Connections cannot be established while a scan is ongoing.
 
   Stops the scan after the given $duration.
-  */
-  scan [block] --duration/Duration?=null --active/bool=false:
+
+  The $interval is the time between the start of two consecutive scan windows. It is
+    given in units of 0.625 ms. If it is 0, the default value of the system is used.
+
+  The $window is the time the scanner is active during a scan window. It is given in
+    units of 0.625 ms. If it is 0, the default value of the system is used. The window
+    must be less than or equal to the interval.
+
+  If $limited-only is true, only limited discoverable devices are reported. Devices
+    declare during advertising whether they are limited (advertising for a limited
+    duration) or general (continuously broadcasting). This flag filters out general
+    devices.
+  */
+  scan -> none
+      --interval/int=0
+      --window/int=0
+      --duration/Duration?=null
+      --limited-only/bool=false
+      --active/bool=false
+      [block]:
+    if interval != 0 and not 4 <= interval <= 16384:
+      throw "Invalid interval"
+    if window != 0 and not 4 <= window <= interval:
+      throw "Invalid window"
     duration-us := duration ? (max 0 duration.in-us) : -1
     resource-state_.clear-state COMPLETED-EVENT_
-    ble-scan-start_ resource_ (not active) duration-us
+    ble-scan-start_ resource_ (not active) duration-us interval window limited-only
     is-macos := system.platform == system.PLATFORM_MACOS
     try:
       while true:

src/primitive.h

@@ -346,7 +346,7 @@ namespace toit {
   PRIMITIVE(create_central_manager, 1)       \
   PRIMITIVE(close, 1)                        \
   PRIMITIVE(release_resource, 1)             \
-  PRIMITIVE(scan_start, 3)                   \
+  PRIMITIVE(scan_start, 6)                   \
   PRIMITIVE(scan_next, 1)                    \
   PRIMITIVE(scan_stop, 1)                    \
   PRIMITIVE(connect, 3)                      \

src/resources/ble_darwin.mm

@@ -826,8 +826,10 @@ - (id)initWithResource:(toit::BleResource*)resource {
 }
 
 PRIMITIVE(scan_start) {
-  ARGS(BleCentralManagerResource, central_manager, bool, passive, int64, duration_us);
-
+  ARGS(BleCentralManagerResource, central_manager, bool, passive, int64, duration_us, int, interval, int, window, bool, limited);
+  USE(interval);
+  USE(window);
+  USE(limited);
   Locker locker(central_manager->scan_mutex());
   bool active = [central_manager->central_manager() isScanning];
 

src/resources/ble_esp32.cc

@@ -2417,7 +2417,7 @@ PRIMITIVE(close) {
 }
 
 PRIMITIVE(scan_start) {
-  ARGS(BleCentralManagerResource, central_manager, bool, passive, int64, duration_us)
+  ARGS(BleCentralManagerResource, central_manager, bool, passive, int64, duration_us, int, interval, int, window, bool, limited)
 
   Locker locker(central_manager->group()->mutex());
 
@@ -2443,10 +2443,10 @@ PRIMITIVE(scan_start) {
   disc_params.passive = passive ? 1 : 0;
 
   /* Use defaults for the rest of the parameters. */
-  disc_params.itvl = 0;
-  disc_params.window = 0;
+  disc_params.itvl = interval;
+  disc_params.window = window;
   disc_params.filter_policy = 0;
-  disc_params.limited = 0;
+  disc_params.limited = limited ? 1 : 0;
 
   err = ble_gap_disc(BLE_ADDR_PUBLIC, duration_ms, &disc_params,
                      BleCentralManagerResource::on_discovery, central_manager->token());

tests/hw/esp32/ble6-advertise-shared.toit

@@ -62,12 +62,17 @@ main-peripheral:
   next-semaphore.down
   peripheral.stop-advertise
 
+  is-general-advertisement := false
   advertise := : | blocks scan-response-blocks |
     advertisement = AdvertisementData blocks
     scan-response := scan-response-blocks
         ? AdvertisementData scan-response-blocks
         : null
-    peripheral.start-advertise --allow-connections advertisement --scan-response=scan-response
+    peripheral.start-advertise
+        advertisement
+        --allow-connections
+        --scan-response=scan-response
+
     next-semaphore.down
     peripheral.stop-advertise
 
@@ -93,9 +98,11 @@ main-peripheral:
     [  // The scan response.
       DataBlock.services-128 [TEST-SERVICE],
     ]
-
-
-
+  advertise.call [
+      DataBlock.flags --general-discovery,
+      DataBlock.name "Test",
+    ]
+    null
 
   done = true
 
@@ -188,7 +195,7 @@ main-central:
 
   advertisement/AdvertisementData? := null
   scan-response/AdvertisementData? := null
-  while true:  // Use loop to be able to break out of the block.
+  while true:  // Use a loop to be able to break out of the block.
     central.scan --duration=(Duration --s=3) --active: | device/RemoteScannedDevice |
       if device.address == address:
         if device.is-scan-response:
@@ -205,6 +212,17 @@ main-central:
 
   characteristic.write #[central-test-counter++]
 
+  // Test limited scanning.
+  central.scan --duration=(Duration --s=1) --limited-only: | device/RemoteScannedDevice |
+    if device.address == address: unreachable
+  // But we should find the device with general scanning.
+  while true:  // Use a loop to be able to break out of the block.
+    central.scan --duration=(Duration --s=3): | device/RemoteScannedDevice |
+      if device.address == address: break
+    unreachable
+
+  characteristic.write #[central-test-counter++]
+
   remote-device.close
   central.close
   adapter.close