nrf5/examples: Adding python eddystone example using ubluepy api.

nrf5/examples/ubluepy_eddystone.py

@@ -0,0 +1,58 @@
+from ubluepy import Peripheral, constants
+
+BLE_GAP_ADV_FLAG_LE_GENERAL_DISC_MODE       = const(0x02)
+BLE_GAP_ADV_FLAG_BR_EDR_NOT_SUPPORTED       = const(0x04)
+
+BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE = const(BLE_GAP_ADV_FLAG_LE_GENERAL_DISC_MODE | BLE_GAP_ADV_FLAG_BR_EDR_NOT_SUPPORTED)
+
+EDDYSTONE_FRAME_TYPE_URL                    = const(0x10)
+EDDYSTONE_URL_PREFIX_HTTP_WWW               = const(0x00) # "http://www".
+EDDYSTONE_URL_SUFFIX_DOT_COM                = const(0x01) # ".com"
+
+def string_to_binarray(text):
+    b = bytearray([])
+    for c in text:
+        b.append(ord(c))
+    return b
+
+def gen_ad_type_content(ad_type, data):
+    b = bytearray(1)
+    b.append(ad_type)
+    b.extend(data)
+    b[0] = len(b) - 1
+    return b
+
+def generate_eddystone_adv_packet(url):
+    # flags
+    disc_mode = bytearray([BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE])
+    packet_flags = gen_ad_type_content(constants.ad_types.AD_TYPE_FLAGS, disc_mode)
+
+    # 16-bit uuid
+    uuid = bytearray([0xAA, 0xFE])
+    packet_uuid16 = gen_ad_type_content(constants.ad_types.AD_TYPE_16BIT_SERVICE_UUID_COMPLETE, uuid)
+
+    # eddystone data
+    rssi = 0xEE # -18 dB, approx signal strength at 0m.
+    eddystone_data = bytearray([])
+    eddystone_data.append(EDDYSTONE_FRAME_TYPE_URL)
+    eddystone_data.append(rssi)
+    eddystone_data.append(EDDYSTONE_URL_PREFIX_HTTP_WWW)
+    eddystone_data.extend(string_to_binarray(url))
+    eddystone_data.append(EDDYSTONE_URL_SUFFIX_DOT_COM)
+
+    # service data
+    service_data = uuid + eddystone_data
+    packet_service_data = gen_ad_type_content(constants.ad_types.AD_TYPE_SERVICE_DATA, service_data)
+
+    # generate advertisment packet
+    packet = bytearray([])
+    packet.extend(packet_flags)
+    packet.extend(packet_uuid16)
+    packet.extend(packet_service_data)
+
+    return packet
+
+def start():
+    adv_packet = generate_eddystone_adv_packet("micropython")  
+    p = Peripheral()
+    p.advertise(data=adv_packet)