Add exposure notifications (#1135)

esphome/components/esp32_ble_tracker/esp32_ble_tracker.h

@@ -28,6 +28,7 @@ class ESPBTUUID {
   bool contains(uint8_t data1, uint8_t data2) const;
 
   bool operator==(const ESPBTUUID &uuid) const;
+  bool operator!=(const ESPBTUUID &uuid) const { return !(*this == uuid); }
 
   esp_bt_uuid_t get_uuid();
 
@@ -74,6 +75,8 @@ class ESPBTDevice {
 
   uint64_t address_uint64() const;
 
+  const uint8_t *address() const { return address_; }
+
   esp_ble_addr_type_t get_address_type() const { return this->address_type_; }
   int get_rssi() const { return rssi_; }
   const std::string &get_name() const { return this->name_; }

esphome/components/exposure_notifications/__init__.py

@@ -0,0 +1,28 @@
+import esphome.codegen as cg
+from esphome import automation
+import esphome.config_validation as cv
+from esphome.components import esp32_ble_tracker
+from esphome.const import CONF_TRIGGER_ID
+
+DEPENDENCIES = ['esp32_ble_tracker']
+
+exposure_notifications_ns = cg.esphome_ns.namespace('exposure_notifications')
+ExposureNotification = exposure_notifications_ns.struct('ExposureNotification')
+ExposureNotificationTrigger = exposure_notifications_ns.class_(
+    'ExposureNotificationTrigger', esp32_ble_tracker.ESPBTDeviceListener,
+    automation.Trigger.template(ExposureNotification))
+
+CONF_ON_EXPOSURE_NOTIFICATION = 'on_exposure_notification'
+
+CONFIG_SCHEMA = cv.Schema({
+    cv.Required(CONF_ON_EXPOSURE_NOTIFICATION): automation.validate_automation(cv.Schema({
+        cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(ExposureNotificationTrigger),
+    }).extend(esp32_ble_tracker.ESP_BLE_DEVICE_SCHEMA)),
+})
+
+
+def to_code(config):
+    for conf in config.get(CONF_ON_EXPOSURE_NOTIFICATION, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID])
+        yield automation.build_automation(trigger, [(ExposureNotification, 'x')], conf)
+        yield esp32_ble_tracker.register_ble_device(trigger, conf)

esphome/components/exposure_notifications/exposure_notifications.cpp

@@ -0,0 +1,49 @@
+#include "exposure_notifications.h"
+#include "esphome/core/log.h"
+#include "esphome/core/helpers.h"
+
+#ifdef ARDUINO_ARCH_ESP32
+
+namespace esphome {
+namespace exposure_notifications {
+
+using namespace esp32_ble_tracker;
+
+static const char *TAG = "exposure_notifications";
+
+bool ExposureNotificationTrigger::parse_device(const ESPBTDevice &device) {
+  // See also https://blog.google/documents/70/Exposure_Notification_-_Bluetooth_Specification_v1.2.2.pdf
+  if (device.get_service_uuids().size() != 1)
+    return false;
+
+  // Exposure notifications have Service UUID FD 6F
+  ESPBTUUID uuid = device.get_service_uuids()[0];
+  // constant service identifier
+  const ESPBTUUID expected_uuid = ESPBTUUID::from_uint16(0xFD6F);
+  if (uuid != expected_uuid)
+    return false;
+  if (device.get_service_datas().size() != 1)
+    return false;
+
+  // The service data should be 20 bytes
+  // First 16 bytes are the rolling proximity identifier (RPI)
+  // Then 4 bytes of encrypted metadata follow which can be used to get the transmit power level.
+  ServiceData service_data = device.get_service_datas()[0];
+  if (service_data.uuid != expected_uuid)
+    return false;
+  auto data = service_data.data;
+  if (data.size() != 20)
+    return false;
+  ExposureNotification notification{};
+  memcpy(&notification.address[0], device.address(), 6);
+  memcpy(&notification.rolling_proximity_identifier[0], &data[0], 16);
+  memcpy(&notification.associated_encrypted_metadata[0], &data[16], 4);
+  notification.rssi = device.get_rssi();
+  this->trigger(notification);
+  return true;
+}
+
+}  // namespace exposure_notifications
+}  // namespace esphome
+
+#endif

esphome/components/exposure_notifications/exposure_notifications.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/core/automation.h"
+#include "esphome/components/esp32_ble_tracker/esp32_ble_tracker.h"
+#include <array>
+
+#ifdef ARDUINO_ARCH_ESP32
+
+namespace esphome {
+namespace exposure_notifications {
+
+struct ExposureNotification {
+  std::array<uint8_t, 6> address;
+  int rssi;
+  std::array<uint8_t, 16> rolling_proximity_identifier;
+  std::array<uint8_t, 4> associated_encrypted_metadata;
+};
+
+class ExposureNotificationTrigger : public Trigger<ExposureNotification>,
+                                    public esp32_ble_tracker::ESPBTDeviceListener {
+ public:
+  bool parse_device(const esp32_ble_tracker::ESPBTDevice &device) override;
+};
+
+}  // namespace exposure_notifications
+}  // namespace esphome
+
+#endif