Skip to content

Instantly share code, notes, and snippets.

@kmdm
Last active June 26, 2024 17:13
Show Gist options
  • Save kmdm/c01c0693b1380d826af200a3e9b2a656 to your computer and use it in GitHub Desktop.
Save kmdm/c01c0693b1380d826af200a3e9b2a656 to your computer and use it in GitHub Desktop.
esphome, esp32 ble tracker and Home Assistant mqtt_room sensors
# MQTT broker configuration
mqtt:
broker: !secret mqtt_broker
username: !secret mqtt_username
password: !secret mqtt_password
discovery: False # Only if you use the HA API usually
id: mqtt_client
# Define the room for this ESP32 node
substitutions:
room_name: bedroom
# Push the room name into a global
globals:
- id: room_topic
type: std::string
initial_value: '"room_presence/${room_name}"'
# Configure the esp32_ble_tracker to push beacon advertisements to MQTT
esp32_ble_tracker:
on_ble_advertise:
- then:
- lambda: |-
if (x.get_ibeacon().has_value()) {
std::string uuid;
esp_bt_uuid_t raw_uuid = x.get_ibeacon().value().get_uuid().get_uuid();
char sbuf[64];
char *bpos = sbuf;
switch (raw_uuid.len) {
case ESP_UUID_LEN_128:
for (int8_t i = 0; i <= 15; i++) {
sprintf(bpos, "%02x", raw_uuid.uuid.uuid128[i]);
bpos += 2;
if (i == 6 || i == 8 || i == 10 || i == 12)
sprintf(bpos++, "-");
}
sbuf[47] = '\0';
uuid.assign(sbuf);
break;
default:
uuid = x.get_ibeacon().value().get_uuid().to_string();
std::transform(uuid.begin(), uuid.end(), uuid.begin(), [](unsigned char c){ return std::tolower(c); });
break;
}
char mbuf[32] = {0};
sprintf(mbuf, "-%hu-%hu", x.get_ibeacon().value().get_major(), x.get_ibeacon().value().get_minor());
uuid.append(mbuf);
int8_t tx_power = x.get_ibeacon().value().get_signal_power();
if (tx_power >= 100) {
tx_power = -69;
}
float dist = pow(10, (float)(tx_power - x.get_rssi()) / (10 * 2));
if (dist < 50) {
ESP_LOGD("ble_adv", "Sending MQTT room update for '%s' (%s): %.03fm (%d rssi, %d sigpow)",
x.get_name().c_str(), uuid.c_str(), dist, x.get_rssi(), tx_power);
id(mqtt_client).publish_json(id(room_topic), [=](JsonObject root) {
root["id"] = uuid;
root["name"] = x.get_name();
root["distance"] = dist;
root["rssi"] = x.get_rssi();
root["tx_power"] = tx_power;
});
} else {
ESP_LOGD("ble_adv", "Skipping MQTT room update for '%s' (%s): %.03fm (%d rssi, %d sigpow)",
x.get_name().c_str(), uuid.c_str(), dist, x.get_rssi(), tx_power);
}
}
# Configure the sensors in Home Assistant as normal:
sensor:
- platform: mqtt_room
name: Test beacon 1
device_id: aabbccdd-eeff-1122-3344-5566778899aa-0001-0002
state_topic: room_presence
@greghesp
Copy link

greghesp commented May 2, 2022

@greghesp Ah, & removed!

I think you mean if (dist < max_distance) otherwise you're only submitting readings over the max_distance which seems to be the opposite of what you'd like!

Out of interest, what's the use case for filtering here instead of just letting HA decide which room the device is in?

Whoops! Bit sleepy still. I'm also not sure if 5 is a correct float.

As for the distance. I've not got presence sensors in every room, so I may go into 1 room and it reports to HA that I'm in room X when I'm not even in a room with a sensor. This way, HA would just report that I'm home, rather than in a room im not

The bottom of this post gives a good example:
https://www.reddit.com/r/homeassistant/comments/ma02pv/how_to_fine_tune_room_assistant_ble/?utm_medium=android_app&utm_source=share

@kmdm
Copy link
Author

kmdm commented May 2, 2022

@greghesp I've updated the gist to include a better calculation for distance using the signal power reported by the BLE beacon. I've added a dist filter but just hardcoded it at 50.

(In the HA companion app you can set what this value is)

The check for a tx_power of 100 is for some weird beacons I have which appear to set the transmit power to 100 so it's just badly fixed back to the default I was using before, it could be unnecessary for you but you can monitor the rssi/tx_power values on the esp32 logs and also the MQTT broker since I've added those values there as well (although any dist >= 50 won't be on MQTT obviously).

@greghesp
Copy link

greghesp commented May 5, 2022

@kmdm What is the dist value measured in? Im assuming its not meters?

@gastonMM
Copy link

gastonMM commented Aug 9, 2022

Thank you so much for sharing it.
modify the max_distance and remove almost all false positives. Is there any other parameter that you recommend me to change?

Thanks again

@mihsu81
Copy link

mihsu81 commented Dec 25, 2022

@kmdm Would it be possible to specify only certain UUIDs?

@greghesp
Copy link

@mihsu81 you can do this on the HA side. It'll just ignore the rest that's sent

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment