tests/multi_bluetooth/ble_mtu: Split peripheral/central-initiated.

btstack only supports central-initiated, so this allows us to have a test
that works on both (ble_mtu.py), and then another one for just the NimBLE
supported behavior (ble_mtu_peripheral.py).
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>

tests/multi_bluetooth/ble_mtu.py

-# Test MTU exchange (initiated by both central and peripheral) and the effect on
-# notify and write size.
-
-# Seven connections are made (four central->peripheral, three peripheral->central).
+# Test MTU exchange (initiated by central) and the effect on notify and write
+# size.
+#
+# See ble_mtu_peripheral.py which tests peripheral-initiated MTU exchange (not supported on btstack).
+#
+# Four connections are made:
 #
 # Test | Requested | Preferred | Result | Notes
 #   0  |  300 (C)  |  256 (P)  |  256   |
 #   1  |  300 (C)  |  200 (P)  |  200   |
 #   2  |  300 (C)  |  400 (P)  |  300   |
 #   3  |  300 (C)  |  50  (P)  |  50    | Shorter than 64 so the notification is truncated.
-#   4  |  290 (P)  |  256 (C)  |  256   |
-#   5  |  290 (P)  |  190 (C)  |  190   |
-#   6  |  290 (P)  |  350 (C)  |  290   |
 #
 # For each connection a notification is sent by the server (peripheral) and a characteristic
 # is written by the client (central) to ensure that the expected size is transmitted.
-#
-# Note: This currently fails on btstack for two reasons:
-# - btstack doesn't truncate writes to the MTU (it fails instead)
-# - btstack (in central mode) doesn't handle the peripheral initiating the MTU exchange
 
 from micropython import const
 import time, machine, bluetooth
@@ -97,37 +92,28 @@ def instance0():
     multitest.globals(BDADDR=ble.config("mac"))
     ((char_handle,),) = ble.gatts_register_services(SERVICES)
     ble.gatts_set_buffer(char_handle, 500, False)
-    print("gap_advertise")
-    ble.gap_advertise(20_000, b"\x02\x01\x06\x04\xffMPY")
     multitest.next()
+
+    default_mtus = [256, 200, 400, 50]
     try:
-        for i in range(7):
-            if i == 1:
-                ble.config(mtu=200)
-            elif i == 2:
-                ble.config(mtu=400)
-            elif i == 3:
-                ble.config(mtu=50)
-            elif i >= 4:
-                ble.config(mtu=290)
-            else:
-                # This is the NimBLE default.
-                ble.config(mtu=256)
+        for i in range(4):
+            ble.config(mtu=default_mtus[i])
+
+            print("gap_advertise")
+            ble.gap_advertise(20_000, b"\x02\x01\x06\x04\xffMPY")
+            multitest.broadcast(f"peripheral:adv:{i}")
 
             # Wait for central to connect to us.
             conn_handle = wait_for_event(_IRQ_CENTRAL_CONNECT, TIMEOUT_MS)
 
-            if i >= 4:
-                print("gattc_exchange_mtu")
-                ble.gattc_exchange_mtu(conn_handle)
-
             mtu = wait_for_event(_IRQ_MTU_EXCHANGED, TIMEOUT_MS)
 
+            multitest.wait(f"client:discovery:{i}")
+
             print("gatts_notify")
             ble.gatts_notify(conn_handle, char_handle, str(i) * 64)
 
-            # Extra timeout while client does service discovery.
-            wait_for_event(_IRQ_GATTS_WRITE, TIMEOUT_MS * 2)
+            wait_for_event(_IRQ_GATTS_WRITE, TIMEOUT_MS)
 
             print("gatts_read")
             data = ble.gatts_read(char_handle)
@@ -135,10 +121,6 @@ def instance0():
 
             # Wait for the central to disconnect.
             wait_for_event(_IRQ_CENTRAL_DISCONNECT, TIMEOUT_MS)
-
-            print("gap_advertise")
-            ble.gap_advertise(20_000, b"\x02\x01\x06\x04\xffMPY")
-
     finally:
         ble.active(0)
 
@@ -147,41 +129,36 @@ def instance0():
 def instance1():
     multitest.next()
     try:
-        for i in range(7):
-            if i < 4:
-                ble.config(mtu=300)
-            elif i == 5:
-                ble.config(mtu=190)
-            elif i == 6:
-                ble.config(mtu=350)
-            else:
-                ble.config(mtu=256)
-
-            # Connect to peripheral and then disconnect.
-            # Extra scan timeout allows for the peripheral to receive the previous disconnect
-            # event and start advertising again.
+        for i in range(4):
+            ble.config(mtu=300)
+
+            multitest.wait(f"peripheral:adv:{i}")
+
             print("gap_connect")
-            ble.gap_connect(BDADDR[0], BDADDR[1], 5000)
+            ble.gap_connect(BDADDR[0], BDADDR[1], TIMEOUT_MS)
             conn_handle = wait_for_event(_IRQ_PERIPHERAL_CONNECT, TIMEOUT_MS)
 
-            if i < 4:
-                print("gattc_exchange_mtu")
-                ble.gattc_exchange_mtu(conn_handle)
+            # Central-initiated mtu exchange.
+            print("gattc_exchange_mtu")
+            ble.gattc_exchange_mtu(conn_handle)
 
             mtu = wait_for_event(_IRQ_MTU_EXCHANGED, TIMEOUT_MS)
 
-            wait_for_event(_IRQ_GATTC_NOTIFY, TIMEOUT_MS)
-
             print("gattc_discover_characteristics")
             ble.gattc_discover_characteristics(conn_handle, 1, 65535)
             value_handle = wait_for_event(_IRQ_GATTC_CHARACTERISTIC_RESULT, TIMEOUT_MS)
             wait_for_event(_IRQ_GATTC_CHARACTERISTIC_DONE, TIMEOUT_MS)
 
-            # Write 20 more than the MTU to test truncation.
+            multitest.broadcast(f"client:discovery:{i}")
+
+            wait_for_event(_IRQ_GATTC_NOTIFY, TIMEOUT_MS)
+
             print("gattc_write")
-            ble.gattc_write(conn_handle, value_handle, chr(ord("a") + i) * (mtu + 20), 1)
+            ble.gattc_write(conn_handle, value_handle, chr(ord("a") + i) * (mtu - 3), 1)
             wait_for_event(_IRQ_GATTC_WRITE_DONE, TIMEOUT_MS)
 
+            time.sleep_ms(300)
+
             # Disconnect from peripheral.
             print("gap_disconnect:", ble.gap_disconnect(conn_handle))
             wait_for_event(_IRQ_PERIPHERAL_DISCONNECT, TIMEOUT_MS)

tests/multi_bluetooth/ble_mtu.py.exp

@@ -31,43 +31,15 @@ _IRQ_GATTS_WRITE
 gatts_read
 characteristic len: 47 d
 _IRQ_CENTRAL_DISCONNECT
-gap_advertise
-_IRQ_CENTRAL_CONNECT
-gattc_exchange_mtu
-_IRQ_MTU_EXCHANGED 256
-gatts_notify
-_IRQ_GATTS_WRITE
-gatts_read
-characteristic len: 253 e
-_IRQ_CENTRAL_DISCONNECT
-gap_advertise
-_IRQ_CENTRAL_CONNECT
-gattc_exchange_mtu
-_IRQ_MTU_EXCHANGED 190
-gatts_notify
-_IRQ_GATTS_WRITE
-gatts_read
-characteristic len: 187 f
-_IRQ_CENTRAL_DISCONNECT
-gap_advertise
-_IRQ_CENTRAL_CONNECT
-gattc_exchange_mtu
-_IRQ_MTU_EXCHANGED 290
-gatts_notify
-_IRQ_GATTS_WRITE
-gatts_read
-characteristic len: 287 g
-_IRQ_CENTRAL_DISCONNECT
-gap_advertise
 --- instance1 ---
 gap_connect
 _IRQ_PERIPHERAL_CONNECT
 gattc_exchange_mtu
 _IRQ_MTU_EXCHANGED 256
-_IRQ_GATTC_NOTIFY 64 0
 gattc_discover_characteristics
 _IRQ_GATTC_CHARACTERISTIC_RESULT UUID('00000000-1111-2222-3333-444444444444')
 _IRQ_GATTC_CHARACTERISTIC_DONE
+_IRQ_GATTC_NOTIFY 64 0
 gattc_write
 _IRQ_GATTC_WRITE_DONE
 gap_disconnect: True
@@ -76,10 +48,10 @@ gap_connect
 _IRQ_PERIPHERAL_CONNECT
 gattc_exchange_mtu
 _IRQ_MTU_EXCHANGED 200
-_IRQ_GATTC_NOTIFY 64 1
 gattc_discover_characteristics
 _IRQ_GATTC_CHARACTERISTIC_RESULT UUID('00000000-1111-2222-3333-444444444444')
 _IRQ_GATTC_CHARACTERISTIC_DONE
+_IRQ_GATTC_NOTIFY 64 1
 gattc_write
 _IRQ_GATTC_WRITE_DONE
 gap_disconnect: True
@@ -88,10 +60,10 @@ gap_connect
 _IRQ_PERIPHERAL_CONNECT
 gattc_exchange_mtu
 _IRQ_MTU_EXCHANGED 300
-_IRQ_GATTC_NOTIFY 64 2
 gattc_discover_characteristics
 _IRQ_GATTC_CHARACTERISTIC_RESULT UUID('00000000-1111-2222-3333-444444444444')
 _IRQ_GATTC_CHARACTERISTIC_DONE
+_IRQ_GATTC_NOTIFY 64 2
 gattc_write
 _IRQ_GATTC_WRITE_DONE
 gap_disconnect: True
@@ -100,43 +72,10 @@ gap_connect
 _IRQ_PERIPHERAL_CONNECT
 gattc_exchange_mtu
 _IRQ_MTU_EXCHANGED 50
-_IRQ_GATTC_NOTIFY 47 3
-gattc_discover_characteristics
-_IRQ_GATTC_CHARACTERISTIC_RESULT UUID('00000000-1111-2222-3333-444444444444')
-_IRQ_GATTC_CHARACTERISTIC_DONE
-gattc_write
-_IRQ_GATTC_WRITE_DONE
-gap_disconnect: True
-_IRQ_PERIPHERAL_DISCONNECT
-gap_connect
-_IRQ_PERIPHERAL_CONNECT
-_IRQ_MTU_EXCHANGED 256
-_IRQ_GATTC_NOTIFY 64 4
-gattc_discover_characteristics
-_IRQ_GATTC_CHARACTERISTIC_RESULT UUID('00000000-1111-2222-3333-444444444444')
-_IRQ_GATTC_CHARACTERISTIC_DONE
-gattc_write
-_IRQ_GATTC_WRITE_DONE
-gap_disconnect: True
-_IRQ_PERIPHERAL_DISCONNECT
-gap_connect
-_IRQ_PERIPHERAL_CONNECT
-_IRQ_MTU_EXCHANGED 190
-_IRQ_GATTC_NOTIFY 64 5
-gattc_discover_characteristics
-_IRQ_GATTC_CHARACTERISTIC_RESULT UUID('00000000-1111-2222-3333-444444444444')
-_IRQ_GATTC_CHARACTERISTIC_DONE
-gattc_write
-_IRQ_GATTC_WRITE_DONE
-gap_disconnect: True
-_IRQ_PERIPHERAL_DISCONNECT
-gap_connect
-_IRQ_PERIPHERAL_CONNECT
-_IRQ_MTU_EXCHANGED 290
-_IRQ_GATTC_NOTIFY 64 6
 gattc_discover_characteristics
 _IRQ_GATTC_CHARACTERISTIC_RESULT UUID('00000000-1111-2222-3333-444444444444')
 _IRQ_GATTC_CHARACTERISTIC_DONE
+_IRQ_GATTC_NOTIFY 47 3
 gattc_write
 _IRQ_GATTC_WRITE_DONE
 gap_disconnect: True

tests/multi_bluetooth/ble_mtu_peripheral.py

+# Test MTU exchange (initiated by peripheral) and the effect on notify and
+# write size.
+#
+# This is not supported on btstack (only the central may initiate MTU exchange).
+#
+# Test | Requested | Preferred | Result | Notes
+#   0  |  290 (P)  |  256 (C)  |  256   |
+#   1  |  290 (P)  |  190 (C)  |  190   |
+#   2  |  290 (P)  |  350 (C)  |  290   |
+#
+# For each connection a notification is sent by the server (peripheral) and a characteristic
+# is written by the client (central) to ensure that the expected size is transmitted.
+
+from micropython import const
+import time, machine, bluetooth
+
+TIMEOUT_MS = 5000
+
+_IRQ_CENTRAL_CONNECT = const(1)
+_IRQ_CENTRAL_DISCONNECT = const(2)
+_IRQ_GATTS_WRITE = const(3)
+_IRQ_PERIPHERAL_CONNECT = const(7)
+_IRQ_PERIPHERAL_DISCONNECT = const(8)
+_IRQ_GATTC_CHARACTERISTIC_RESULT = const(11)
+_IRQ_GATTC_CHARACTERISTIC_DONE = const(12)
+_IRQ_GATTC_WRITE_DONE = const(17)
+_IRQ_GATTC_NOTIFY = const(18)
+_IRQ_MTU_EXCHANGED = const(21)
+
+SERVICE_UUID = bluetooth.UUID("A5A5A5A5-FFFF-9999-1111-5A5A5A5A5A5A")
+CHAR_UUID = bluetooth.UUID("00000000-1111-2222-3333-444444444444")
+CHAR = (
+    CHAR_UUID,
+    bluetooth.FLAG_READ | bluetooth.FLAG_WRITE | bluetooth.FLAG_NOTIFY,
+)
+SERVICE = (
+    SERVICE_UUID,
+    (CHAR,),
+)
+SERVICES = (SERVICE,)
+
+waiting_events = {}
+
+
+def irq(event, data):
+    if event == _IRQ_CENTRAL_CONNECT:
+        print("_IRQ_CENTRAL_CONNECT")
+        waiting_events[event] = data[0]
+    elif event == _IRQ_CENTRAL_DISCONNECT:
+        print("_IRQ_CENTRAL_DISCONNECT")
+    elif event == _IRQ_GATTS_WRITE:
+        print("_IRQ_GATTS_WRITE")
+    elif event == _IRQ_PERIPHERAL_CONNECT:
+        print("_IRQ_PERIPHERAL_CONNECT")
+        waiting_events[event] = data[0]
+    elif event == _IRQ_PERIPHERAL_DISCONNECT:
+        print("_IRQ_PERIPHERAL_DISCONNECT")
+    elif event == _IRQ_GATTC_CHARACTERISTIC_RESULT:
+        if data[-1] == CHAR_UUID:
+            print("_IRQ_GATTC_CHARACTERISTIC_RESULT", data[-1])
+            waiting_events[event] = data[2]
+        else:
+            return
+    elif event == _IRQ_GATTC_CHARACTERISTIC_DONE:
+        print("_IRQ_GATTC_CHARACTERISTIC_DONE")
+    elif event == _IRQ_GATTC_WRITE_DONE:
+        print("_IRQ_GATTC_WRITE_DONE")
+    elif event == _IRQ_GATTC_NOTIFY:
+        print("_IRQ_GATTC_NOTIFY", len(data[-1]), chr(data[-1][0]))
+    elif event == _IRQ_MTU_EXCHANGED:
+        print("_IRQ_MTU_EXCHANGED", data[-1])
+        waiting_events[event] = data[-1]
+
+    if event not in waiting_events:
+        waiting_events[event] = None
+
+
+def wait_for_event(event, timeout_ms):
+    t0 = time.ticks_ms()
+    while time.ticks_diff(time.ticks_ms(), t0) < timeout_ms:
+        if event in waiting_events:
+            return waiting_events.pop(event)
+        machine.idle()
+    raise ValueError("Timeout waiting for {}".format(event))
+
+
+# Acting in peripheral role.
+def instance0():
+    multitest.globals(BDADDR=ble.config("mac"))
+    ((char_handle,),) = ble.gatts_register_services(SERVICES)
+    ble.gatts_set_buffer(char_handle, 500, False)
+    multitest.next()
+    try:
+        for i in range(3):
+            ble.config(mtu=290)
+
+            print("gap_advertise")
+            ble.gap_advertise(20_000, b"\x02\x01\x06\x04\xffMPY")
+            multitest.broadcast(f"peripheral:adv:{i}")
+
+            # Wait for central to connect to us.
+            conn_handle = wait_for_event(_IRQ_CENTRAL_CONNECT, TIMEOUT_MS)
+
+            # Peripheral-initiated mtu exchange.
+            print("gattc_exchange_mtu")
+            ble.gattc_exchange_mtu(conn_handle)
+
+            mtu = wait_for_event(_IRQ_MTU_EXCHANGED, TIMEOUT_MS)
+
+            multitest.wait(f"client:discovery:{i}")
+
+            print("gatts_notify")
+            ble.gatts_notify(conn_handle, char_handle, str(i) * 64)
+
+            wait_for_event(_IRQ_GATTS_WRITE, TIMEOUT_MS)
+
+            print("gatts_read")
+            data = ble.gatts_read(char_handle)
+            print("characteristic len:", len(data), chr(data[0]))
+
+            # Wait for the central to disconnect.
+            wait_for_event(_IRQ_CENTRAL_DISCONNECT, TIMEOUT_MS)
+
+            print("gap_advertise")
+            ble.gap_advertise(20_000, b"\x02\x01\x06\x04\xffMPY")
+
+    finally:
+        ble.active(0)
+
+
+# Acting in central role.
+def instance1():
+    multitest.next()
+    try:
+        default_mtus = [256, 190, 350]
+        for i in range(3):
+            ble.config(mtu=default_mtus[i])
+
+            multitest.wait(f"peripheral:adv:{i}")
+
+            print("gap_connect")
+            ble.gap_connect(BDADDR[0], BDADDR[1], 5000)
+            conn_handle = wait_for_event(_IRQ_PERIPHERAL_CONNECT, TIMEOUT_MS)
+
+            mtu = wait_for_event(_IRQ_MTU_EXCHANGED, TIMEOUT_MS)
+
+            print("gattc_discover_characteristics")
+            ble.gattc_discover_characteristics(conn_handle, 1, 65535)
+            value_handle = wait_for_event(_IRQ_GATTC_CHARACTERISTIC_RESULT, TIMEOUT_MS)
+            wait_for_event(_IRQ_GATTC_CHARACTERISTIC_DONE, TIMEOUT_MS)
+
+            multitest.broadcast(f"client:discovery:{i}")
+
+            wait_for_event(_IRQ_GATTC_NOTIFY, TIMEOUT_MS)
+
+            # Write 20 more than the MTU to test truncation.
+            print("gattc_write")
+            ble.gattc_write(conn_handle, value_handle, chr(ord("a") + i) * (mtu + 20), 1)
+            wait_for_event(_IRQ_GATTC_WRITE_DONE, TIMEOUT_MS)
+
+            # Disconnect from peripheral.
+            print("gap_disconnect:", ble.gap_disconnect(conn_handle))
+            wait_for_event(_IRQ_PERIPHERAL_DISCONNECT, TIMEOUT_MS)
+    finally:
+        ble.active(0)
+
+
+ble = bluetooth.BLE()
+ble.active(1)
+ble.irq(irq)

tests/multi_bluetooth/ble_mtu_peripheral.py.exp

+--- instance0 ---
+gap_advertise
+_IRQ_CENTRAL_CONNECT
+gattc_exchange_mtu
+_IRQ_MTU_EXCHANGED 256
+gatts_notify
+_IRQ_GATTS_WRITE
+gatts_read
+characteristic len: 253 a
+_IRQ_CENTRAL_DISCONNECT
+gap_advertise
+gap_advertise
+_IRQ_CENTRAL_CONNECT
+gattc_exchange_mtu
+_IRQ_MTU_EXCHANGED 190
+gatts_notify
+_IRQ_GATTS_WRITE
+gatts_read
+characteristic len: 187 b
+_IRQ_CENTRAL_DISCONNECT
+gap_advertise
+gap_advertise
+_IRQ_CENTRAL_CONNECT
+gattc_exchange_mtu
+_IRQ_MTU_EXCHANGED 290
+gatts_notify
+_IRQ_GATTS_WRITE
+gatts_read
+characteristic len: 287 c
+_IRQ_CENTRAL_DISCONNECT
+gap_advertise
+--- instance1 ---
+gap_connect
+_IRQ_PERIPHERAL_CONNECT
+_IRQ_MTU_EXCHANGED 256
+gattc_discover_characteristics
+_IRQ_GATTC_CHARACTERISTIC_RESULT UUID('00000000-1111-2222-3333-444444444444')
+_IRQ_GATTC_CHARACTERISTIC_DONE
+_IRQ_GATTC_NOTIFY 64 0
+gattc_write
+_IRQ_GATTC_WRITE_DONE
+gap_disconnect: True
+_IRQ_PERIPHERAL_DISCONNECT
+gap_connect
+_IRQ_PERIPHERAL_CONNECT
+_IRQ_MTU_EXCHANGED 190
+gattc_discover_characteristics
+_IRQ_GATTC_CHARACTERISTIC_RESULT UUID('00000000-1111-2222-3333-444444444444')
+_IRQ_GATTC_CHARACTERISTIC_DONE
+_IRQ_GATTC_NOTIFY 64 1
+gattc_write
+_IRQ_GATTC_WRITE_DONE
+gap_disconnect: True
+_IRQ_PERIPHERAL_DISCONNECT
+gap_connect
+_IRQ_PERIPHERAL_CONNECT
+_IRQ_MTU_EXCHANGED 290
+gattc_discover_characteristics
+_IRQ_GATTC_CHARACTERISTIC_RESULT UUID('00000000-1111-2222-3333-444444444444')
+_IRQ_GATTC_CHARACTERISTIC_DONE
+_IRQ_GATTC_NOTIFY 64 2
+gattc_write
+_IRQ_GATTC_WRITE_DONE
+gap_disconnect: True
+_IRQ_PERIPHERAL_DISCONNECT