Integrations

ESPGeiger exposes radiation data through several channels (MQTT, Webhook, JSON endpoint). This page shows how to connect these to common monitoring and automation platforms.

JSON Endpoint

The built-in web server exposes a JSON endpoint at /json:

http://192.168.1.100/json

Response:

{"ut":66080,"c":30.00,"s":0.17,"c5":26.19,"c15":27.55,"cs":0.50,"r":175.0,"tc":29099,"mem":22447,"rssi":-69,"tube":1,"sat":0,"hv":394.00,"t":20.78,"tu":0,"h":48.20,"p":1027.40}

Field	Description
`ut`	Uptime in seconds
`c`	Current CPM
`s`	Current μSv/h
`c5`	5-minute smoothed CPM
`c15`	15-minute smoothed CPM
`cs`	Current CPS
`r`	μSv conversion ratio
`tc`	Total clicks since boot
`mem`	Free heap memory in bytes
`rssi`	WiFi signal strength in dBm
`tube`	`1` while counts are arriving, `0` once the tube has been silent longer than expected for its count rate
`sat`	`1` when the count rate is close to the tube’s dead-time limit, so readings will under-report
`hv`	HV reading in volts (ESPGeiger-HW only)

Environmental sensor

Present only when a BME280, BMP280, AHTxx or AHT20 + BMP280 combo sensor is detected. Each field is left out when the sensor does not measure it, for example h on a BMP280.

Field	Description
`t`	Temperature, in the unit chosen in the sensor settings
`tu`	Temperature unit: `0` °C, `1` °F, `2` K
`h`	Relative humidity, %
`p`	Pressure in hPa, corrected to sea level when an elevation is set

MQTT, WebAPI, the webhook and UDP always send temperature in °C; only /json follows the display unit.

UDP receiver builds

Field	Description
`loss`	Packet loss on the feed, as a percentage (appears once a producer has been heard)

/json?raw=1 adds memory and load diagnostics; see HTTP endpoint schemas.

GeigerLog

GeigerLog is a free cross-platform log/plot tool for Geiger counters. ESPGeiger exposes a GeigerLog-compatible endpoint at /lastdata that works with GeigerLog’s built-in WiFiServer device (the one that polls a device URL).

Configure GeigerLog

In GeigerLog open Device → WiFiServer → Config WiFiServer Device.
Set the IP address and port to the ESPGeiger device (port 80).
Point the data URL at /lastdata.
Save, then connect the WiFiServer device.

The /lastdata endpoint returns a single comma-separated line in GeigerLog’s 12-variable order. Fields the device can’t provide are left empty:

22.50, 0.37, 21.90, , 21.40, , , , 24.50, 1013.00, 48.00, 0.0720

Position	GeigerLog variable	ESPGeiger value
1	CPM	Current CPM
2	CPS	Current CPS
3	CPM1st	5-minute CPM
5	CPM2nd	15-minute CPM
9	Temp	Temperature, if an environment sensor is fitted
10	Press	Pressure, if fitted
11	Humid	Humidity, if fitted
12	Xtra	HV in volts (ESPGeiger-HW), otherwise dose rate in µSv/h

Positions 4, 6, 7 and 8 (CPS1st / CPS2nd / CPM3rd / CPS3rd) are always empty.

Notes

Polling is driven by GeigerLog - ESPGeiger responds on each request, so cadence is whatever you configure on the GeigerLog side.
The endpoint is always available; there is no toggle in the ESPGeiger portal.
Environment fields appear only when a sensor is detected; otherwise those positions stay empty.

Prometheus (native `/metrics`)

ESPGeiger exposes a native Prometheus text exposition endpoint at /metrics. No proxy or exporter needed.

Scrape config

# prometheus.yml
scrape_configs:
  - job_name: espgeiger
    metrics_path: /metrics
    scrape_interval: 30s
    static_configs:
      - targets:
          - 192.168.1.100   # your device(s)
          - 192.168.1.101

For automatic discovery, each device advertises a _geiger._tcp mDNS service on port 80 (alongside the standard _http._tcp), so you can point your service-discovery layer at _geiger._tcp to find every ESPGeiger on the network.

Sample output

# HELP device_info Device metadata; value always 1. Join via on(chipid) for naming.
# TYPE device_info gauge
device_info{chipid="d5536d",name="Garage",model="ESPGeiger-HW",ver="0.11.0",env="espgeigerhw"} 1

# HELP geiger_cpm Counts per minute (window label selects averaging period)
# TYPE geiger_cpm gauge
geiger_cpm{chipid="d5536d",window="1m"} 31.50
geiger_cpm{chipid="d5536d",window="5m"} 30.20
geiger_cpm{chipid="d5536d",window="15m"} 29.80

# HELP geiger_cps Instantaneous counts per second
geiger_cps{chipid="d5536d"} 0.52

# HELP geiger_usv_per_hour Dose rate in microsieverts per hour
geiger_usv_per_hour{chipid="d5536d"} 0.2086

# HELP geiger_lifetime_clicks_total Total clicks counted over device life
# TYPE geiger_lifetime_clicks_total counter
geiger_lifetime_clicks_total{chipid="d5536d"} 1845231

# HELP device_uptime_seconds Seconds since boot
device_uptime_seconds{chipid="d5536d"} 90523

# HELP device_free_heap_bytes Free heap memory
device_free_heap_bytes{chipid="d5536d"} 19432

# HELP device_wifi_rssi_dbm WiFi signal strength
device_wifi_rssi_dbm{chipid="d5536d"} -54

# HELP geiger_usv_ratio CPM per uSv/h conversion ratio
geiger_usv_ratio{chipid="d5536d"} 151.00

# HELP geiger_tube_alive 1 while counts arrive, 0 once silent longer than expected for the rate
geiger_tube_alive{chipid="d5536d"} 1

# HELP geiger_saturated 1 when the count rate is near the dead-time limit
geiger_saturated{chipid="d5536d"} 0

# HELP device_hv_volts Tube high voltage
device_hv_volts{chipid="d5536d"} 392.00

# HELP env_temperature_celsius Temperature
env_temperature_celsius{chipid="d5536d"} 21.63

# HELP env_humidity_percent Relative humidity
env_humidity_percent{chipid="d5536d"} 48.20

# HELP env_pressure_hpa Pressure, sea-level corrected when an elevation is set
env_pressure_hpa{chipid="d5536d"} 1026.38

# HELP geiger_pulse_interval_seconds Inter-pulse intervals in seconds, log2 buckets
# TYPE geiger_pulse_interval_seconds histogram
geiger_pulse_interval_seconds_bucket{chipid="d5536d",le="0.000064"} 0
geiger_pulse_interval_seconds_bucket{chipid="d5536d",le="0.000128"} 0
...
geiger_pulse_interval_seconds_bucket{chipid="d5536d",le="+Inf"} 1845231
geiger_pulse_interval_seconds_count{chipid="d5536d"} 1845231

Metrics

Metric	Type	Description
`device_info`	gauge	Always 1; labels carry name, model, firmware version and build
`geiger_cpm`	gauge	Counts per minute; `window` label is `1m`, `5m` or `15m`
`geiger_cps`	gauge	Counts per second
`geiger_usv_per_hour`	gauge	Dose rate in μSv/h
`geiger_usv_ratio`	gauge	CPM per μSv/h conversion ratio
`geiger_lifetime_clicks_total`	counter	Clicks over the device’s life
`geiger_tube_alive`	gauge	`1` while counts arrive, `0` once the tube has been silent longer than expected for its count rate
`geiger_saturated`	gauge	`1` when the count rate is close to the tube’s dead-time limit
`geiger_pulse_interval_seconds`	histogram	Time between pulses, cumulative since boot
`device_uptime_seconds`	gauge	Seconds since boot
`device_free_heap_bytes`	gauge	Free heap memory
`device_wifi_rssi_dbm`	gauge	WiFi signal strength
`device_hv_volts`	gauge	Tube high voltage (ESPGeiger-HW only)
`env_temperature_celsius`	gauge	Temperature, always °C
`env_humidity_percent`	gauge	Relative humidity
`env_pressure_hpa`	gauge	Pressure in hPa, corrected to sea level when an elevation is set
`geiger_udp_loss_percent`	gauge	Packet loss on the feed (UDP receiver builds, once a producer has been heard)

The env_ metrics appear only when a sensor is detected and each only if the sensor measures it.

Label model

Operational metrics carry only chipid - a stable device ID that never changes. Friendly name, model and firmware version live in the separate device_info metric. This means:

Renaming a device in the portal does not fork its historical time series.
Dashboard joins use on(chipid) group_left(name) to bring in the friendly name.

PromQL examples

# Current CPM with friendly name as legend
geiger_cpm{window="1m"} * on(chipid) group_left(name) device_info

# Dose rate averaged over 1 hour
avg_over_time(geiger_usv_per_hour[1h])
  * on(chipid) group_left(name) device_info

# Alert when any device exceeds 1 µSv/h sustained for 5 min
- alert: RadiationHigh
  expr: avg_over_time(geiger_usv_per_hour[5m]) > 1
  labels:
    severity: warning
  annotations:
    summary: " dose rate sustained above 1 µSv/h"

# Devices that haven't reported in 5 min
time() - timestamp(geiger_cpm{window="1m"}) > 300

Notes

The endpoint is always available; there is no toggle in the portal.
Histogram bucket boundaries are powers of two starting at 64 µs (inter-pulse interval). The top bucket is +Inf.
geiger_lifetime_clicks_total is a Prometheus counter (monotonically increasing); use rate() for click rate.

InfluxDB via Telegraf

Telegraf can poll /json and write to InfluxDB. Add one field block per JSON field you want:

[[inputs.http]]
  urls = ["http://192.168.1.100/json"]
  data_format = "json_v2"
  name_override = "espgeiger"
  [[inputs.http.json_v2]]
    [[inputs.http.json_v2.field]]
      path = "c"
      rename = "cpm"
      type = "float"
    [[inputs.http.json_v2.field]]
      path = "s"
      rename = "usv_h"
      type = "float"

[[outputs.influxdb_v2]]
  urls = ["http://influxdb:8086"]
  token = "YOUR_TOKEN"
  organization = "your-org"
  bucket = "radiation"

Node-RED

Node-RED can poll the JSON endpoint and route data anywhere:

[
  {
    "id": "poll",
    "type": "inject",
    "repeat": "60",
    "topic": "",
    "payload": "",
    "payloadType": "date"
  },
  {
    "id": "http",
    "type": "http request",
    "method": "GET",
    "url": "http://192.168.1.100/json",
    "ret": "obj"
  }
]

Wire poll → http → your destination (MQTT, database, dashboard, webhook, etc.).

Home Assistant

If using MQTT with Home Assistant autodiscovery enabled, ESPGeiger sensors appear automatically. See Home Assistant for details.

For REST polling without MQTT:

# configuration.yaml
rest:
  - resource: http://192.168.1.100/json
    scan_interval: 30
    sensor:
      - name: "Radiation CPM"
        value_template: ""
        unit_of_measurement: "CPM"
      - name: "Radiation uSv/h"
        value_template: ""
        unit_of_measurement: "μSv/h"
        device_class: "radiation"
      - name: "ESPGeiger WiFi RSSI"
        value_template: ""
        unit_of_measurement: "dBm"
        device_class: "signal_strength"
      - name: "ESPGeiger Free Heap"
        value_template: ""
        unit_of_measurement: "B"

Grafana Dashboard

Once data is in Prometheus or InfluxDB, Grafana can chart it. For Prometheus, start from the PromQL examples above, for example geiger_cpm{window="1m"}.

Integrations

JSON Endpoint

Environmental sensor

UDP receiver builds

GeigerLog

Configure GeigerLog

Notes

Prometheus (native /metrics)

Scrape config

Sample output

Metrics

Label model

PromQL examples

Notes

InfluxDB via Telegraf

Node-RED

Home Assistant

Grafana Dashboard

Prometheus (native `/metrics`)