BLE Multiple Connections

docs/keycodes.md

@@ -268,6 +268,8 @@
 
 ## [Bluetooth Keys]
 
-|Key                          |Aliases            |Description                 |
-|-----------------------------|-------------------|----------------------------|
-|`KC.BT_CLEAR_BONDS`          |`KC.BT_CLR`        |Clears all stored bondings  |
+|Key                          |Aliases            |Description                       |
+|-----------------------------|-------------------|----------------------------------|
+|`KC.BT_CLEAR_BONDS`          |`KC.BT_CLR`        |Clears all stored bondings        |
+|`KC.BT_NEXT_CONN`            |`KC.BT_NXT`        |Selects the next BT connection    |
+|`KC.BT_PREV_CONN`            |`KC.BT_PRV`        |Selects the previous BT connection|

kmk/ble.py

@@ -1,70 +1,101 @@
 from adafruit_ble import BLERadio
-from adafruit_ble.advertising import Advertisement
 from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
 from adafruit_ble.services.standard.hid import HIDService
-from kmk.hid import (
-    HID_REPORT_SIZES,
-    AbstractHID,
-    HIDReportTypes,
-    HIDUsage,
-    HIDUsagePage,
-)
+from kmk.hid import HID_REPORT_SIZES, AbstractHID
 
 BLE_APPEARANCE_HID_KEYBOARD = 961
+# Hardcoded in CPy
+MAX_CONNECTIONS = 2
 
 
 class BLEHID(AbstractHID):
     def post_init(self, ble_name='KMK Keyboard', **kwargs):
-        self.devices = {}
-
-        hid = HIDService()
-
-        advertisement = ProvideServicesAdvertisement(hid)
-        advertisement.appearance = BLE_APPEARANCE_HID_KEYBOARD
-
-        ble = BLERadio()
-        ble.name = ble_name
-        # ble.tx_power = 2
-
-        if not ble.connected:
-            ble.start_advertising(advertisement)
-            while not ble.connected:
-                pass
-
-        for device in hid.devices:
-            us = device.usage
-            up = device.usage_page
-
-            if up == HIDUsagePage.CONSUMER and us == HIDUsage.CONSUMER:
-                self.devices[HIDReportTypes.CONSUMER] = device
-                continue
-
-            if up == HIDUsagePage.KEYBOARD and us == HIDUsage.KEYBOARD:
-                self.devices[HIDReportTypes.KEYBOARD] = device
-                continue
-
-            if up == HIDUsagePage.MOUSE and us == HIDUsage.MOUSE:
-                self.devices[HIDReportTypes.MOUSE] = device
-                continue
-
-            if up == HIDUsagePage.SYSCONTROL and us == HIDUsage.SYSCONTROL:
-                self.devices[HIDReportTypes.SYSCONTROL] = device
-                continue
+        self.conn_id = -1
+
+        self.ble = BLERadio()
+        self.ble.name = ble_name
+        self.hid = HIDService()
+        self.hid.protocol_mode = 0  # Boot protocol
+
+        # Security-wise this is not right. While you're away someone turns
+        # on your keyboard and they can pair with it nice and clean and then
+        # listen to keystrokes.
+        # On the other hand we don't have LESC so it's like shouting your
+        # keystrokes in the air
+        if not self.ble.connected or not self.hid.devices:
+            self.start_advertising()
+
+        self.conn_id = 0
+
+    @property
+    def devices(self):
+        """Search through the provided list of devices to find the ones with the
+        send_report attribute."""
+        if not self.ble.connected:
+            return []
+
+        result = []
+        # Security issue:
+        # This introduces a race condition. Let's say you have 2 active
+        # connections: Alice and Bob - Alice is connection 1 and Bob 2.
+        # Now Chuck who has already paired with the device in the past
+        # (this assumption is needed only in the case of LESC)
+        # wants to gather the keystrokes you send to Alice. You have
+        # selected right now to talk to Alice (1) and you're typing a secret.
+        # If Chuck kicks Alice off and is quick enough to connect to you,
+        # which means quicker than the running interval of this function,
+        # he'll be earlier in the `self.hid.devices` so will take over the
+        # selected 1 position in the resulted array.
+        # If no LESC is in place, Chuck can sniff the keystrokes anyway
+        for device in self.hid.devices:
+            if hasattr(device, "send_report"):
+                result.append(device)
+
+        return result
+
+    def _check_connection(self):
+        devices = self.devices
+        if not devices:
+            return False
+
+        if self.conn_id >= len(devices):
+            self.conn_id = len(devices) - 1
+
+        if self.conn_id < 0:
+            return False
+
+        if not devices[self.conn_id]:
+            return False
+
+        return True
 
     def hid_send(self, evt):
-        # int, can be looked up in HIDReportTypes
-        reporting_device_const = self.report_device[0]
+        if not self._check_connection():
+            return
 
-        report_size = HID_REPORT_SIZES[reporting_device_const]
+        device = self.devices[self.conn_id]
 
-        while len(evt) < report_size + 1:
+        while len(evt) < len(device._characteristic.value) + 1:
             evt.append(0)
 
-        return self.devices[reporting_device_const].send_report(
-            evt[1 : report_size + 1]
-        )
+        return device.send_report(evt[1:])
 
     def clear_bonds(self):
         import _bleio
 
         _bleio.adapter.erase_bonding()
+
+    def next_connection(self):
+        self.conn_id = (self.conn_id + 1) % len(self.devices)
+
+    def previous_connection(self):
+        self.conn_id = (self.conn_id - 1) % len(self.devices)
+
+    def start_advertising(self):
+        advertisement = ProvideServicesAdvertisement(self.hid)
+        advertisement.appearance = BLE_APPEARANCE_HID_KEYBOARD
+
+        self.ble.start_advertising(advertisement)
+
+    def stop_advertising(self):
+        self.ble.stop_advertising()

kmk/handlers/stock.py

@@ -259,3 +259,13 @@ def led_mode_breathe(key, state, *args, **kwargs):
 def bt_clear_bonds(key, state, *args, **kwargs):
     state.config._hid_helper_inst.clear_bonds()
     return state
+
+
+def bt_next_conn(key, state, *args, **kwargs):
+    state.config._hid_helper_inst.next_connection()
+    return state
+
+
+def bt_prev_conn(key, state, *args, **kwargs):
+    state.config._hid_helper_inst.previous_connection()
+    return state

kmk/keys.py

@@ -642,6 +642,8 @@ def _argumented_key(*user_args, **user_kwargs):
 make_key(names=('LED_MODE_PLAIN', 'LED_M_P'), on_press=handlers.led_mode_static)
 make_key(names=('LED_MODE_BREATHE', 'LED_M_B'), on_press=handlers.led_mode_breathe)
 make_key(names=('BT_CLEAR_BONDS', 'BT_CLR'), on_press=handlers.bt_clear_bonds)
+make_key(names=('BT_NEXT_CONN', 'BT_NXT'), on_press=handlers.bt_next_conn)
+make_key(names=('BT_PREV_CONN', 'BT_PRV'), on_press=handlers.bt_prev_conn)
 
 
 make_key(

user_keymaps/dzervas/lab68.py

@@ -21,7 +21,7 @@
 
 keyboard.debug_enabled = True
 
-keyboard.col_pins = (mcp.get_pin(0), mcp.get_pin(1), mcp.get_pin(2), mcp.get_pin(3), mcp.get_pin(4), mcp.get_pin(5), mcp.get_pin(5), mcp.get_pin(6), mcp.get_pin(7), mcp.get_pin(8), mcp.get_pin(9), mcp.get_pin(10), mcp.get_pin(11), mcp.get_pin(12), mcp.get_pin(13), mcp.get_pin(14))
+keyboard.col_pins = (mcp.get_pin(8), mcp.get_pin(9), mcp.get_pin(10), mcp.get_pin(11), mcp.get_pin(12), mcp.get_pin(13), mcp.get_pin(14), mcp.get_pin(15), mcp.get_pin(4), mcp.get_pin(5), mcp.get_pin(6), mcp.get_pin(7), mcp.get_pin(3), mcp.get_pin(2), mcp.get_pin(1), )
 keyboard.row_pins = (board.D7, board.D6, board.D5, board.D3, board.D2)
 keyboard.diode_orientation = DiodeOrientation.COLUMNS
 
@@ -61,13 +61,14 @@
     # `------------------------------------------------------------------------------------------+------+------'
     # CLR: Clear bonds
     [
-        XXXXXXX, KC.F1,   KC.F2,   KC.F3,   KC.F4,    KC.F5,   KC.F6,   KC.F7,   KC.F8,   KC.F9,   KC.F10,  KC.F11,   KC.F12,  XXXXXXX, KC.BT_CLR,
-        KC.TAB,  XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX,  XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, KC.PSCR, XXXXXXX, KC.PAUSE, _______, XXXXXXX, _______,
-        KC.ESC,  XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX,  XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX,  XXXXXXX, XXXXXXX, _______,
-        KC.LSFT, XXXXXXX, KC.MPLY, KC.MSTP, KC.MPRV,  KC.MNXT, KC.VOLD, KC.VOLU, KC.MUTE, XXXXXXX, XXXXXXX, KC.RSFT,  XXXXXXX, _______, XXXXXXX,
-        KC.LCTL, KC.LGUI, KC.LALT, XXXXXXX, XXXXXXX,  KC.SPC,  XXXXXXX, XXXXXXX, FN,      KC.RALT, KC.RCTL, _______,  XXXXXXX, _______, _______,
+        XXXXXXX, KC.F1,   KC.F2,   KC.F3,   KC.F4,    KC.F5,   KC.F6,   KC.F7,   KC.F8,   KC.F9,   KC.F10,  KC.F11,    KC.F12,  XXXXXXX, KC.BT_CLR,
+        KC.TAB,  XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX,  XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, KC.PSCR, XXXXXXX, KC.PAUSE,  _______, XXXXXXX, _______,
+        KC.ESC,  XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX,  XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX, XXXXXXX,   XXXXXXX, XXXXXXX, _______,
+        KC.LSFT, XXXXXXX, KC.MPLY, KC.MSTP, KC.MPRV,  KC.MNXT, KC.VOLD, KC.VOLU, KC.MUTE, XXXXXXX, XXXXXXX, KC.RSFT,   XXXXXXX, _______, XXXXXXX,
+        KC.LCTL, KC.LGUI, KC.LALT, XXXXXXX, XXXXXXX,  KC.SPC,  XXXXXXX, XXXXXXX, FN,      KC.RALT, KC.RCTL, KC.BT_PRV, XXXXXXX, _______, KC.BT_NXT,
     ],
 ]
 
 if __name__ == '__main__':
     keyboard.go(hid_type=HIDModes.BLE, ble_name='Lab68')
+    # keyboard.go(hid_type=HIDModes.USB)